Leak in EGR system - how to seal?

[mtthsk]

Hello,

Two weeks my Disco 4 MY14 3.0 SDV6 started to create problems. It now has roughly 208k on the clock.

I parked the car normally in the evening and the next morning the engine would start, but almost immediately die directly afterwards. After a while i managed to get a fault code with the IID tool: P0105-16, Manifold absolute pressure/barometric circuit - General electrical failure, leading me to replace the MAP sensor.

A few days later, new sensor installed, the engine started well and the car ran smoothly. However, after driving for a while, i got the "Reduced Power" light in the dashboard. This happened when driving uphill at 2500 rpm upwards. When i parked the car, I got the P006A-00 MAP/MAF correlation error. So this lead me to thinking, it must have something to to with the secondary turbo or the air intake system for that.

I read a dozen stories of a cracked inlet manifold and how a pain that is to replace yourself. Luckily I got proof of the previous owner that the inlet manifolds were replaced about 40k km and about 3 years ago.
I could also not visibly see any crack in any hose, manifold or throttle body. Therefore i decided to get a smoke tester to find a potential leak.

I found that the system is leaking where the LH Vacuum EGR Cooler Bypass Actuator is located:

https://www.disco3.co.uk/gallery/albums/userpics/67315/Screenshot_2024-01-20_165824.jpg




https://www.disco3.co.uk/gallery/albums/userpics/67315/IMG_7682~0.jpg



Actually seen some smoke on the other side at the same place as well, just a little less smoke.

Could that be the cause of the error messages i am getting? It would make sense to me that this results in a MAP reading that isn't expected based on the MAF reading...

Did anyone already had a leak in that postition as well? Is this sealable? I am hoping so because otherwise it would mean a replacement of the whole EGR unit, wouldn't it?

Another thing that i found online regarding my symptoms, was that the throttle body valve likes to be stuck, so i decided to take the throttle body off, check the valve and give it a nice clean. It was a bit dirty, but not too bad, i would say. Where the EGR pipes fit in, however, it was quite dirty, so i cleaned that as well. The valve opens back up, when i push it down, although when pushed down a bit more, it stays closed. Is it supposed to be opening automatically also when pushing it down quite far?

I also already removed and cleaned the compressor shutoff valve on the bottom front right of the vehicle. Bit of thick oil came out, but rod and flap moove freely, also when actuated via vacuum.

During multiple test drives last week i occasionally got the error codes:
P00CF-62 Barometric pressure - Turbocharger/supercharger boost sensor A correlation. (only got that one once, didnt come back up).
P0235-16 Turbocharger/supercharger boost sensor A circuit - General electrical failure.
P1247-00 Turbocharger boost pressure low.

But the one fault that is always coming back is P0105-16. Lately when the reduced power light came on, i only got the P006A-00 fault.
Tomorrow i will also try checking and replacing the secondary turbocharger boost pressure sensor as that is quite accessible.



Any help and further ideas are much appreciated!

Matt

[Porker]

At about the same km’s as your vehicle my top intercooler hose failed but I read that you can’t find any evidence of this happening. Sorry I’m of no other assistance.

[DiscoJeffster]

3L engines aren’t common to fail on intercooler hoses like a 2.7L.

Your leak won’t be caused by a small leak at the seal there. It’ll be somewhere more pronounced. It’s remotely possible that it’s a faulty MAF but I really doubt it.

If you are not seeing it with the smoke test it might be that the leak needs boost pressure to crack it open and leak.

Lay some white paper on the engine between the engine and the engine cover. Place one piece each over the manifolds and one over the throttle body. Put the cover back on to lock the paper in place. Take it for a hard spin and see if you can trigger the fault, then head home and check your paper. If it’s a leak around there I’d expect to find soot on the paper somewhere.

[mtthsk]

Hi there, little update:

thanks DiscoJeffster for your reply. I could believe that a leak would only be visible during an actual drive rather than with a smoke machine, needing the boost pressure.
Two weeks ago, before i got hold of a smoke tester, i already tried the paper method and couldn't find anything. On my drive home from work today I repeated the test and placed three sheets of white paper over both inlet manifolds and over the throttle body. I then provoked the fault and shortly after inspected the sheets. "Unfortunately" there were no significant stains. Only like 2 very little black spots that i presume came from the surface being not entirely clean. Am i looking for a very obvious black sheets or could a very small stain already indicate a leak in these positions?

Anyway, I will test it again with a longer and more harder drive, possibly triggering and resetting the fault multiple times to really tick that one of my list.

Do you really rule out the leak(s) at the EGR rods there? I made a small video to show the amount of smoke escaping:

https://share.icloud.com/photos/0f56GtezODOfXBvr4bQd6XmKA
The video shows the LH side, the RH side appears to be leaking less, probably half of what is seen in the video.

As I have read in another thread that the secondary turbocharger boost pressure sensor was the cause of a similar problem, I replaced the sensor together with its vacuum hose:

188698188699

Sadly this did not cure the fault.

I also removed the compressor shut-off valve (CSOV) again, cleaned it again and tested if it sticks. I would say this does look quite good, doesn't it?:

https://share.icloud.com/photos/09fjiafff9A1TitneyDfnLMiA

I found a little bit of oil in it again, although i had it disconnected and cleaned just 5 days ago. Back then it looked like this:

https://www.icloud.com/photos/#087iEhKRv7YDW-nVuE0qBMndQ

(Hope the video links are woking also for you)

Another thing causing these faults apparently can be a stuck secondary turbo actuator. After I got the wheel and three heatshields out of the way, I tried to locate this actuator rod that a lot of people are refering to, to possibly free it with a coat hanger or something similar, but i could not at all find it.. Most guides seem to direct to the primary turbo or on the (seemingly) easier 2.7L... So, I would be thankful for any guidance as to get there (is it even possible in situ?)

While being under there and replacing the secondary pressure sensor I found the piece where its vacuum line goes quite dirty:
188700
I therefore smoke-tested this route explicitly with the CSOV removed and the smoke-pipe inserted directly to its bigger top hose. No leaks were visible. Again, I don't know if real boost pressure is needed to show a possible leak, but at least I found that suspiciously dirty. However it seems nearly impossible to get to that hose to properly inspect it without dismantling everything.

Again with test drives in the last days i only ever got the P0105-16 - MAP/barometric circuit general electric failure and the P006A - MAP/MAF correlation error. The more I think about it, and considering that I have changed both (or are there more?) MAP sensors and I get (plausible, I believe) values from both MAF sensors, there has to be air escaping somewhere. Interestingly the P0105-16 general electric circuit fault seems to appear at every start of the vehicle (I need to double check if the Pending flag is then set and later Confirmed, after the reduced performance event triggers).
I find it very suspicious that I get this error while not even driving. Leads me to think there is something not connected. But then again I can see MAP live values, so it must work generally(?).

This is how my MAF sensors look like:
188701
I thought they are looking very clean. However, I might try to swap them, just to see what happens.

Right now I am running out of ideas pretty much. I heard a faulty vacuum hose could also be a cause of these symptoms, but as there are a ton of them, which ones are the really important ones?

I am really grateful for any input, thoughts or ideas on my problem.

Thanks guys,
Matt

[Eric SDV6SE]

I need to refresh my memory, but i believe this fault is related to the solenoids themselves that are in the vacuum system for the primary and secondary turbo actuation. These are tied into the MAF and MAP sensors. Up at the top of the engine near the front trace the vac lines to their respective solenoids, you can remove these and test them on a multimeter, open circuit resistance should be infinite, if you read 0 ohms, coil is shorted and you need a new one.

Re the soot from the egrs actuator, thats normal, its just a plain bushing, not a true seal, you can ignore that as the source of your errors.

Re oil staining from a split manifold, youll see a big smear of oul and soot, when they fail they usually go with a pop. The Y piece failure is more gradual.

Also check where the 90deg elbow inlet piece connects into the y piece, the o ring seal in there is known to fail, causing loss of boost pressure and MAP sensor issues too

[mtthsk]

I need to refresh my memory, but i believe this fault is related to the solenoids themselves that are in the vacuum system for the primary and secondary turbo actuation. These are tied into the MAF and MAP sensors. Up at the top of the engine near the front trace the vac lines to their respective solenoids, you can remove these and test them on a multimeter, open circuit resistance should be infinite, if you read 0 ohms, coil is shorted and you need a new one.

Re the soot from the egrs actuator, thats normal, its just a plain bushing, not a true seal, you can ignore that as the source of your errors.

Re oil staining from a split manifold, youll see a big smear of oul and soot, when they fail they usually go with a pop. The Y piece failure is more gradual.

Also check where the 90deg elbow inlet piece connects into the y piece, the o ring seal in there is known to fail, causing loss of boost pressure and MAP sensor issues too

Thanks so much for your help!


I have measured the open circuit resistance of solenoids 7 & 8 in the following picture:
188712
These are the „Secondary Turbocharger Turbine Shut-off Solenoid Valve“(7)
and „Secondary Turbocharger Compressor Shut-off Solenoid Valve“(8)
7 had a 25,2 Ohms and 8 had 25,5 Ohms.
Are you sure about them needing to have infinite resistance?
At least for the CSOV solenoid I believe it is working as I could verify the CSOV itself moving (either after 3 minutes @ idle or when driving and accelerating above 2500 rpm)

When driving home from work today I got the reduced engine power warning light. At that time I didn‘t have the engine above 2500rpm at all. It was a flat road and the engine at ~1500 rpm. So, thats at a new state it happens..
When arriving home I read the errors and got:
188713
These are all errors I got before, but havent had them occur at that low revs.

I also inspected the 90deg air intake piece and replaced the o-ring that goes to the throttle body. I actually found some dirt underneath that region and thought that might be a place thats leaking. However, also with the new o-ring, I still get restricted performance and the P0105–16 and P006A-00 errors. Anyway, I gave it a good clean, so I should be able to tell if something leaks there after a while.

While having that part off I inspected the throttle body flap again and I don‘t know if that already counts as sticking:

https://share.icloud.com/photos/0e0REf9g_ygtSUFw4SpSD9EKw
What do you think?

I was also able to provoke the reduced power and mentioned P0105-16 and P006A-00 faults while being parked and revving up. Before I thought it needed real load, but that happens to be not neccessary. I recorded several live values, but I am not entirely sure how to interprete them. For example the following screenshots show Mass air flow and MAP readings together with engine speed. The highest engine speed marks the occurence of the reduced power event. After that i took the foot of the gas.
188711
188710
I dont know if I interprete too much into that, but the MAP and MAF already drops before the rpms do. Is that right?

Any guidance and help in how to interprete these values and what other values are relevant is much appreciated.

Also swapped both MAF-sensors, which had no effect at all.

Thanks again @all for supporting me.
Matt

[Eric SDV6SE]

Im not 100% on the infinite resistance, the fact you have >0 Ohms is a good thing, so both solenoids are working.

When i had my D4, i inspected and replaced all the vac lines i could see, as well as the joiners, the T and Y pieces in the vac lines, these can and di crack, causing odd vacuum leaks and triggering weird sensor issues.

[mtthsk]

Im not 100% on the infinite resistance, the fact you have >0 Ohms is a good thing, so both solenoids are working.

When i had my D4, i inspected and replaced all the vac lines i could see, as well as the joiners, the T and Y pieces in the vac lines, these can and di crack, causing odd vacuum leaks and triggering weird sensor issues.

All right, how did you check those vac lines? Just visually or did you hook up a pump? If so, what to expect? Should every line hold a vacuum when stationary?

A vac lines replacement kit would be nice..

[mtthsk]

Or I am wondering if i can smoke test the vacuum lines as well? Or would that damage the system somehow?

[Eric SDV6SE]

I bought a roll of suitable black rubber vac hose and a connector kit off ebay and simply replaced each and every line and joiner i could see, excluding the hard plastic lines. Easy enough to check, with engine running, disconnect at the solenoids and feel for a vacuum with your finger, the hose should stick to your finger. Work your way around all hoses and connectors if you dont get a vacuum to find the leak. Can get fancy with a vac gauge, but i didnt bother. Mine was a MY11, so at about 10yo i thought it was time to replace them.

Smoke tests wouldn't work as its a negative pressure system.

[LRD414]

When driving home from work today I got the reduced engine power warning light.
At that time I didn‘t have the engine above 2500rpm at all.
It was a flat road and the engine at ~1500 rpm. So, thats at a new state it happens..
When arriving home I read the errors and got:
188713
These are all errors I got before, but havent had them occur at that low revs.



I got logged fault codes P006A-00, P1247-00, P00BD-07 and P0235-94 which was the top intercooler hose at 3 years and 77,000km.
It was not an obvious crack or tear. Hose replaced and errors never returned. 3L 2014 TDV6

My thread for more details (see first few posts) here > Restricted Performance Event (https://www.aulro.com/afvb/l319-discovery-3-and-4-a/253796-restricted-performance-event.html)

Probably worth replacing as it's easy and relatively cheap.

Cheers,
Scott

[mtthsk]

I got logged fault codes P006A-00, P1247-00, P00BD-07 and P0235-94 which was the top intercooler hose at 3 years and 77,000km.
It was not an obvious crack or tear. Hose replaced and errors never returned. 3L 2014 TDV6

My thread for more details (see first few posts) here > Restricted Performance Event (https://www.aulro.com/afvb/l319-discovery-3-and-4-a/253796-restricted-performance-event.html)

Probably worth replacing as it's easy and relatively cheap.

Cheers,
Scott

Hi Scott,

thanks for your reply. I just ordered the top intercooler hose. You're right, it's relatively cheap and very easy to replace, so might be worth trying. Maybe the smoke testing doesn't put enough pressure in the system to show a tear.

Last weekend I drove ~600 km to another city and back. I noticed that the restricted performance does not necessarily relate solely to the second turbo kicking in at 2500 rpms. It's more load-related than solely that. When driving on the autobahn and overtaking at ~130 km/h the fault regularly showed up, when staying below 120 km/h and not on an uphill section the fault would not occur.

Before the drive back home I inspected the throttle body butterfly valve again, as it was sticking a bit. I noticed again that there was a little bit of space on the left hand-side and no space on the right-hand side of the valve, meaning it has shifted a bit and would therefore stick when fully closed. I managed to gently push the valve back to its original position, so the valve does not stick anymore. I kind of had high hopes in this fix, as I have seen this problem quite a few times on Youtube, but unfortunately it had no effect.

Thanks again for your help @ all.

The one thing I could not check, is the secondary turbo actuator rod. Can someone guide me where to gain access to that part, trying to free it with a coat hangar or similar? Most posts only tell how to do it on the 2.7L, but not on the 3.0L MY14.


Cheers,
Matt

[LRD414]

…
The one thing I could not check, is the secondary turbo actuator rod. Can someone guide me where to gain access to that part, trying to free it with a coat hangar or similar? Most posts only tell how to do it on the 2.7L, but not on the 3.0L MY14.

Post 5 in my linked thread has a link to another thread which details access to the secondary turbo actuator. And post 7 in my thread has a photo of what you’ll find on a MY14 when using a mirror

[shack]

I'm guessing you are using a gap tool to get the faults and the charts?

I know nothing about the gap but I'm guessing you can also record a downloadable log?

If so, could you post one here?

Both MAF sensors, MAP sensor and IAT as well as boost and AAP would be required.

If anything has multiple sensor like the MAF does, they will also be required.

[mtthsk]

Post 5 in my linked thread has a link to another thread which details access to the secondary turbo actuator. And post 7 in my thread has a photo of what you’ll find on a MY14 when using a mirror

Hi Scott,
thanks for taking the time.
I believe the linked thread is talking about the Compressor Shut-Off Valve (CSOV), isn‘t it? The one that is easily accessible behind the wheel. I removed and cleaned that one already.
The one I am thinking of checking is the Turbine Shut-Off Valve (TSOV), that, i believe, sits right at the secondary turbo and is therefore hard to reach, hence the question.

But I am not sure if, in case of a TSOV failure, other fault codes should be showing up.

Cheers,
Matt

[mtthsk]

I'm guessing you are using a gap tool to get the faults and the charts?

I know nothing about the gap but I'm guessing you can also record a downloadable log?

If so, could you post one here?

Both MAF sensors, MAP sensor and IAT as well as boost and AAP would be required.

If anything has multiple sensor like the MAF does, they will also be required.

Hi shack,
exactly, I am using the GAP IID Tool. I can also export the log files, so sharing them here is not a problem. I will record a new log with the mentioned values:
MAF and MAP values are clear. Does IAT means Intake Air Temperature? What boost value exactly are you looking for? And AAP stands for Ambient Air Pressure?

Thanks for helping out!

Matt

[stuarth44]

Hi Scott,

thanks for your reply. I just ordered the top intercooler hose. You're right, it's relatively cheap and very easy to replace, so might be worth trying. Maybe the smoke testing doesn't put enough pressure in the system to show a tear.

Last weekend I drove ~600 km to another city and back. I noticed that the restricted performance does not necessarily relate solely to the second turbo kicking in at 2500 rpms. It's more load-related than solely that. When driving on the autobahn and overtaking at ~130 km/h the fault regularly showed up, when staying below 120 km/h and not on an uphill section the fault would not occur.

Before the drive back home I inspected the throttle body butterfly valve again, as it was sticking a bit. I noticed again that there was a little bit of space on the left hand-side and no space on the right-hand side of the valve, meaning it has shifted a bit and would therefore stick when fully closed. I managed to gently push the valve back to its original position, so the valve does not stick anymore. I kind of had high hopes in this fix, as I have seen this problem quite a few times on Youtube, but unfortunately it had no effect.

Thanks again for your help @ all.

The one thing I could not check, is the secondary turbo actuator rod. Can someone guide me where to gain access to that part, trying to free it with a coat hangar or similar? Most posts only tell how to do it on the 2.7L, but not on the 3.0L MY14.


Cheers,
Matt
when my turbo arm was sticking I got a garden pressure sprayer with a metre long wand, i ,mixed 1/2 2 stroke oil half kerosene and soaked the area
that was on my tdv6, it solved the boost problem
guten tag

[shack]

Hi shack,
exactly, I am using the GAP IID Tool. I can also export the log files, so sharing them here is not a problem. I will record a new log with the mentioned values:
MAF and MAP values are clear. Does IAT means Intake Air Temperature? What boost value exactly are you looking for? And AAP stands for Ambient Air Pressure?

Thanks for helping out!

MattCorrect on all fronts.

Don't worry about boost.

Cheers

[mtthsk]

Hi there,

today I managed to log the requested live values on my drive home from work. I exported them as a .csv-file, but I am not sure how to display them as a graph in Excel. The IIDTool also allows for export in PDF, where all the graphs are displayed together and also seperately. As it shows the total drive time, zooming in is required. (I attached both, csv & pdf file)

A few explanations:
- The whole log duration is about 300 seconds. I stopped the log while driving after the fault occured.
- I started to try to provoke the error "naturally", by just putting my foot down, starting at ~227s of the log. This did not trigger the fault. As I was gaining speed quickly, I had to slow down again.
- I then triggered the fault by using the command shift, manually shifting down three times to increase rpms. This starts at ~259s of the log.
- The fault appeared at ~272,5s of the log.

As it is quite hard to use the scale in the PDF, I prepared screenshots of the (I believe) relevant 3s where the fault occured:

188842
(full resolution picture here: iCloud Photos - Apple iCloud (https://share.icloud.com/photos/084DosqcKVrOILKFbH2aeiDdA) )

On the first screenshot, I marked the gear shifts and the position that I got the reduced performance ("Fault" in the picture). The values below the graphs show the values at the time of the vertical line (272.25s, 273.25s, 274.25s).
I find it interesting that normally the MAF values from bank 1 and 2 appear to be resulting in the "Mass air flow"-Value. In the third graph of the picture the Mass air flow-value however is lower than the bank 2(&1)-value. But then again, I don't know where the Mass air flow value comes from. Maybe it is the (wrongly?) calculated value that results from bank 1 and bank 2 readings + MAP reading (so an expected value)?

Maybe someone else can see more in these graphs than I can.

The triggered fault(s) are P006A-00 and P0105-16 again. The latter however has already been logged when I drove to work this morning (no reduced performance then). The P006A-00 was logged exactly when the fault occured.
188845

Also the top intercooler hose arrived today, so I will test swapping that one out tomorrow.
I ordered some vacuum hoses as well, I plan to check them more thoroughly on the weekend.

Thanks again @all for your help and time. It is really much appreciated!

Cheers,
Matt

[Eric SDV6SE]

Can you log map,maf and boost pressure? I think you'll see a strong correlation there.

[DiscoJeffster]

Can you log map,maf and boost pressure? I think you'll see a strong correlation there.

Well given it’s a P006a I agree, but no amount of logging is going to say where the leak is.

OP, have you tried swapping the MAF sensors around? A change in failure behaviour might indicate a faulty MAF. I think this is really unlikely but if you can’t find a leak, which P006a implies, possibly worth a try

[mtthsk]

Well given it’s a P006a I agree, but no amount of logging is going to say where the leak is.

OP, have you tried swapping the MAF sensors around? A change in failure behaviour might indicate a faulty MAF. I think this is really unlikely but if you can’t find a leak, which P006a implies, possibly worth a try

Hi,

yes I swapped the MAF sensors, to no effect.
Also swapped top intercooler hose this morning, to no effect.
One thing I noticed today that the bank 2 reading (primary) seems to not get above 180 g/s. Is that the point where the intake circuit 1 (secondary) should kick in?
because that is where a fault occured this morning. Shortly before i revved the engine and got a plausible reading from both MAFs with no fault. At the second try the MAF bank 2 peaked at 180g/s and the fault occured. Bank 1 MAF showed only 1.3 g/s or so.

Maybe this indicates a faulty solenoid, valve, actuator or whatever, so that the second air intake circuit doesnt open?
What valve exactly would be responsible for that? CSOV and/or TSOV?

Cheers,
Matt

[DiscoJeffster]

Weirdly bank 2 is the primary MAF used at low load, with bank 1 the one that kicks in at 2500rpm ish, as I recall.

[Eric SDV6SE]

Clutching at straws i guess, but when one of the turboes failed in mine, i recall the air control valve was also swapped out. Seems to me that this may be the cause of your problems, the control valve doesnt work properly, boost can't be built up as expected based on load and engine rpm, sensor reads low map and throws a code.

[shack]

This could all be wrong... So apologies if it is.

Have only just had a chance to take a look.

Of course nothing lines up with what I normally do tuning wise.. So had to start again.

I haven't got time to fully read the thread, and I have no idea how the 3.0 system works, but these are my observations.

^^read disclaimer!

MAF bank 2 seems to be always operational.

MAF bank 1 kicks in somewhere around 2500 RPM.

Both banks added together are roughly equivalent to total mass air flow...I don't know how much discrepancy is allowed.

IAT seems either incorrectly labelled or is reading abnormally low.

AAP has very little deviation which is also unusual, and if the manifold absolute pressure reading is indeed what it says...
I.e. absolute, something is wrong, it's reading lower than AAP.

In fact I'd say it's defaulting at lower pressures.

If everything is labelled correctly and is displayed at the correct factor, I'd say the map sensor is either faulty or the wrong one.

These are just calculations based on basic direct injection diesel theory, if there are any tricks going on behind the scenes this data will be wrong.

Just out of interest, does the gap tool display boost or calculated boost, it would be interesting to watch that number as you drive along.

What was your altitude and ambient temp when you did the log?

The log was interesting actually, took about an hour to convert everything, but I can now handle logs from the gap tool and make them legible!

[mtthsk]

Weirdly bank 2 is the primary MAF used at low load, with bank 1 the one that kicks in at 2500rpm ish, as I recall.
Yes, thats how I understood it as well. Sorry if my last post was a little confusing.

However, as I was getting faults way below 2000 rpms (while accelerating at relatively high speed uphill), I believe this could be more Load than solely rpm related.

I think we might be onto something here.

My theory: Maybe it is not an air leak, but a problem with opening the secondary air intake system. Because on my last post with the logs, the primary MAF peaks at 180g/s, so the car somehow calculates something and trys to activate the secondary air intake, which would then lower the primary MAF reading. As this does not happen (sticky valve / actuator maybe?) it goes into fault. You can see that I have no secondary MAF reading in the yesterday logs. And I could also observe this today, when, first both MAFs showed a reading and fault didnt occur and when trying again, only primary MAF shows flow and secondary MAF stays at very low flow.

[mtthsk]

Clutching at straws i guess, but when one of the turboes failed in mine, i recall the air control valve was also swapped out. Seems to me that this may be the cause of your problems, the control valve doesnt work properly, boost can't be built up as expected based on load and engine rpm, sensor reads low map and throws a code.
Hi Eric,
thanks for the reply. What exactly do you refer to with air control valve? It would fit the symptoms, I guess…

Cheers,
Matt

[mtthsk]

This could all be wrong... So apologies if it is.

Have only just had a chance to take a look.

Of course nothing lines up with what I normally do tuning wise.. So had to start again.

I haven't got time to fully read the thread, and I have no idea how the 3.0 system works, but these are my observations.

^^read disclaimer!

MAF bank 2 seems to be always operational.

MAF bank 1 kicks in somewhere around 2500 RPM.

Both banks added together are roughly equivalent to total mass air flow...I don't know how much discrepancy is allowed.

IAT seems either incorrectly labelled or is reading abnormally low.

AAP has very little deviation which is also unusual, and if the manifold absolute pressure reading is indeed what it says...
I.e. absolute, something is wrong, it's reading lower than AAP.

In fact I'd say it's defaulting at lower pressures.

If everything is labelled correctly and is displayed at the correct factor, I'd say the map sensor is either faulty or the wrong one.

These are just calculations based on basic direct injection diesel theory, if there are any tricks going on behind the scenes this data will be wrong.

Just out of interest, does the gap tool display boost or calculated boost, it would be interesting to watch that number as you drive along.

What was your altitude and ambient temp when you did the log?

The log was interesting actually, took about an hour to convert everything, but I can now handle logs from the gap tool and make them legible!

Hi shack,

wow thanks for your thoughts! It is really appreciated!

Regarding the MAF 1 and 2 I believe youre totally right how the system works.

IAT seems correct. As I am based in Germany and we have about 2-4 degrees Celcius right now.

AAP also seems correct to me, as this should always be the constant pressure of roughly 100 kPa, or no?

MAP sensor was swapped, so I would guess its ok, but not guaranteed of course.

Out of curiosity: how did you convert the csv logs to make them readable?

I will try to check for boost related values and report back.
EDIT: Boost related live values are:
Boost pressure actuator - Bank 2 - Controller output
Boost pressure actuator - Bank 2 - Desired position
Boost pressure actuator - Bank 2 - Measured position
Commanded boost actuator control - Bank 2
Boost absolute pressure - Raw value

I logged these values together with engine rpms, map value and maf bank 1 (secondary). The first screenshot shows where I believe the fault was triggered. I was just accelerating, no manual shifts. And also there was an air flow in bank 1, basically disproving my theory that the opening of the second air intake was causing this.
188852 (original: iCloud Photos - Apple iCloud (https://share.icloud.com/photos/039-XO03P-oqflxdwVcXA85ZA))
for reference values a screenshot from afterwards:
188853 (original: iCloud Photos - Apple iCloud (https://share.icloud.com/photos/076DzcGOELxFtbT0nG_oHR5IA))

@shack: csv is attached, maybe you can see something here. I dont know how to interprete them at the moment.

Cheers
Matt

[shack]

Can you have the gap tool in normal driving mode and get a calculated boost number?

As mentioned before, I have no idea with these cars, but at idle manifold absolute pressure and ambient pressure should be roughly the same.

In the log I did yesterday, manifold absolute pressure was sitting at 76 kpa, this translates to roughly 2300 above MSL.

Germany may be that elevated, I don't know.

But the AAP sensor says 100kpa, so that's basically sea level.

[mtthsk]

Can you have the gap tool in normal driving mode and get a calculated boost number?
The only boost related values available, I have logged as attached to my previous post. The csv file has normal driving in it (screenshots are only zoomed to the time of the fault).
Do you also need the PDF graph for the log or any other values with the boost values? The GAP Tool only allows for 8 values to be logged at the same time.


As mentioned before, I have no idea with these cars, but at idle manifold absolute pressure and ambient pressure should be roughly the same.

In the log I did yesterday, manifold absolute pressure was sitting at 76 kpa, this translates to roughly 2300 above MSL.

Germany may be that elevated, I don't know.

But the AAP sensor says 100kpa, so that's basically sea level.

Here in northern Germany we are roughly at sea level, so 100kPa should be expected, i guess.

Why the MAP is significantly lower I dont know, unfortunately. I will have a look tomorrow again and compare the pressure values at idle.

One thing that keeps stuck in my head is the general electrical failure related to the barometric/map circuit that is pretty much always logged when the car starts, independant of if the fault occurs later or not. This leads me to thinking that maybe during startup and testing maybe an actuator or solenoid is not fully functioning…

[DiscoJeffster]

I have to keep reminding myself we’re talking a diesel here and not petrol. All my petrol knowledge is saying “ of course it’s lower, it’s in vacuum at idle”. Petrol head steps out of the chat.

[Eric SDV6SE]

Hi Eric,
thanks for the reply. What exactly do you refer to with air control valve? It would fit the symptoms, I guess…

Cheers,
Matt

The 3.0l sdv6 is a sequential turbo as you know. The primary spools up and creates early boost pressure in the system and provides low down torque. As ling as the loads remain fairly low, the secondary turbo is left alone and idles along. When engine load demands it, the air control valve (sitting at the front left of the engine in the line from primary to secondary turbo) is actuated, by solenoid and based on maf and map readings to the ecu. This is basically a flap valve, allows air flow from the primary to the secondary turbo side, the secondary spools up and provides extra power. Seems to me the signal or correlation beyween map and bost control is not working as it should. This video expains it better than me, the ACV is activated at 2500rpm and relies on map and maf sensors along with rpm, throttle etc.

Range Rover and Land Rover 2010 new TDV6 3.0 Advanced Sequential Turbo Diesel Engine Animation - YouTube (https://youtu.be/bnx5sBYWMmk'si=6xoEuPoq0CUiD90o)

[shack]

I don't know if the gap tool and the Bosch ECU will provide live data with the ignition on and engine off, a number of tools won't.

But if it will, a reading with the engine off would be interesting.

If the MAP sensor (manifold ABSOLUTE pressure) ever reads significantly lower than the AAP sensor (AMBIENT air pressure) then there's an issue with one of them.

I'm my experience, significantly lower = 3-4 kPa.

A static test (engine off) they should be identical, engine running the MAP should be higher.

Based on your current climate and elevation figures, there is something wrong with the MAP sensor or circuit.

It would be handy if anyone on here with a gap tool and twin turbo 3.0 at sea level could post a log from theirs.

[mtthsk]

I don't know if the gap tool and the Bosch ECU will provide live data with the ignition on and engine off, a number of tools won't.

But if it will, a reading with the engine off would be interesting.

The tool and ECU allow for recording with ony the ignition on.



If the MAP sensor (manifold ABSOLUTE pressure) ever reads significantly lower than the AAP sensor (AMBIENT air pressure) then there's an issue with one of them.

I'm my experience, significantly lower = 3-4 kPa.

A static test (engine off) they should be identical, engine running the MAP should be higher.

I agree with you, with everything off the pressure "inside" should be the same as "outside". I have not really noticed this before, thanks for pointing this out!

I just did a ignition on test with a couple of related values:
188868

A 25 kPa difference between ambient air pressure and what the sensor is suggesting inside the throttle body seems way off. And it also totally complies with what you figured out based on the first log:

Based on your current climate and elevation figures, there is something wrong with the MAP sensor or circuit.

This would actually be really good:

It would be handy if anyone on here with a gap tool and twin turbo 3.0 at sea level could post a log from theirs.
Or even just some MAP readings with engine on and off.

It seems weird to me, though, as the MAP sensor was the first thing I replaced, because the car wouldn't even keep running for 1 second after starting. After swapping it out, everything seemed to be normal until i noticed the reduced performance when hitting above 2500 rpms for the first time a couple of days later.
Would be happy to swap it again and put the faults to bed, though...

Cheers,
Matt

[shack]

I'm not suggesting that it's definitely the MAP sensor, but that reading certainly seems odd to me.

I'm also surprised it won't run without the MAP sensor, I would imagine most of the fuelling is handled by the MAF's.

[DiscoJeffster]

https://uploads.tapatalk-cdn.com/20240209/a3859e8719b54af8af3c6fbedca02f17.jpg
I might have expected to see this error if in fact the correlation is wrong, but that said, it is weird they’re different. Baro seems to be from a sensor in the ECU module itself according to the above.

It might pay to did out the ecu from behind the battery and check the connectors are all clean and no water/corrosion has made their way in. The value delta implies a corroded/poor connection giving a value delta.

[shack]

Baro seems to be from a sensor in the ECU module itself according to the above.


Hmmmm, where are you seeing that?

Have you chopped off part of the image where it refers to that?

[DiscoJeffster]

Hmmmm, where are you seeing that?

Have you chopped off part of the image where it refers to that?

It refers to replacing the engine control module or map sensor as the resolution to inconsistent values hence I’ve inferred it.
I am still not sure where it’s getting the baro value from.

[DiscoJeffster]

Rereading, that DTC shows up under the 4L petrol. Still, the 3L engine does not show a distinct BARO sensor anywhere (nor does the 4L either).

So, how does it get a Baro value?

If it initially uses the map to get a baro reading then it’s not very dynamic over a journey and then wouldn’t explain the delta we can see. There must be a baro sensor therefore somewhere and I feel it might be in the ECU.

I’m also working the assumption the baro is correct and the map is off in the data above.

Q: Was the map replaced with a brand new sensor? Genuine? Correct one?

[mtthsk]

Q: Was the map replaced with a brand new sensor? Genuine? Correct one?


The sensor was not genuine, but new. It is this one:https://www.ebay.de/itm/324816890036'mkcid=16&mkevt=1&mkrid=707-127634-2357-0&ssspo=zlDQMGD1Q3G&sssrc=4429486&ssuid=vk6laFx4S8u&var=&widget_ver=artemis&media=COPY

I will pull the sensor from the throttle body and check its value. And I will also install the old, genuine one and read its value with only ignition on (if it still shows a value, i dont know).

If both still show way below 100kPa, I will check the wiring for any damage and/or install a new, genuine sensor, as this would indicate to me that something is definitely wrong with the sensor.

I actually inspected the ECU behind the battery when installing a new boost pressure sensor with its hose. To get more room I removed the battery and could ser the ECU. It was bone-dry in there with a little bit of dust which I cleaned. (My battery sits in the RH side, as my car is LH-drive)

Thanks for your continued support!

Cheers,
Matt

[shack]

That is an EXTREMELY cheap MAP sensor.

[mtthsk]

That is an EXTREMELY cheap MAP sensor.

Yes, that is what I figured now after checking it again… on different websites this is listed with double the price, though…
Anyway, I am happy to swap with genuine this time, for sure!

[DiscoJeffster]

The sensor was not genuine, but new. It is this one:https://www.ebay.de/itm/324816890036'mkcid=16&mkevt=1&mkrid=707-127634-2357-0&ssspo=zlDQMGD1Q3G&sssrc=4429486&ssuid=vk6laFx4S8u&var=&widget_ver=artemis&media=COPY

I will pull the sensor from the throttle body and check its value. And I will also install the old, genuine one and read its value with only ignition on (if it still shows a value, i dont know).

If both still show way below 100kPa, I will check the wiring for any damage and/or install a new, genuine sensor, as this would indicate to me that something is definitely wrong with the sensor.

I actually inspected the ECU behind the battery when installing a new boost pressure sensor with its hose. To get more room I removed the battery and could ser the ECU. It was bone-dry in there with a little bit of dust which I cleaned. (My battery sits in the RH side, as my car is LH-drive)

Thanks for your continued support!

Cheers,
Matt

It might still pay to remove the ECU connector just to be 100% sure there’s no corrosion. I doubt there is - it’s normally the trans ecu that corrodes.

I’m clutching at straws about the baro/map value and even if it’s a thing.

[DiscoJeffster]

Mine with ignition off


https://uploads.tapatalk-cdn.com/20240210/ddf4b48baaa9bb13629919617bb0aa65.jpg

[mtthsk]

Hi there,
I believe the new, cheap MAP sensor may well have caused all the trouble I have had for the last 4 weeks...


Mine with ignition off


https://uploads.tapatalk-cdn.com/20240210/ddf4b48baaa9bb13629919617bb0aa65.jpg

Thanks DiscoJeffster for posting your values, that confirms how it should look like.

Remember how the cheap MAP sensor read:


I just did a ignition on test with a couple of related values:
188868
There was a 25kPa difference between atmospheric and MAP reading.

I have first pulled the cheap MAP sensor from the throttle body and re-read the value. It still showed 75kPa.

Then I disconnected the sensor altogether, resulting in these values:
188880
It just reads very low voltage resulting in a very low MAP, of course.

I then plugged in the old, genuine MAP sensor and also fitted it to its throttle body position. The values I got are shown here:
188879
Now, thats a lot closer! This just shows to me 100% that you guys were right with the sensor being faulty.

I proceeded with a stationary test with revving the engine up to above 3000 rpms. Normally, with the cheap MAP sensor, the fault would occur here after about 5 seconds in these conditions max. It did not occur with the old genuine sensor, even when keeping the revs for a longer time.

Later that day I took the car for a drive and manually shifted down a couple of gears to be above 3000 rpms again. Again, the fault would not trigger!

Today I will take the car for a harder testdrive on the autobahn and see if the fault is really gone.


It seems weird to me, though, as the MAP sensor was the first thing I replaced, because the car wouldn't even keep running for 1 second after starting. After swapping it out, everything seemed to be normal until i noticed the reduced performance when hitting above 2500 rpms for the first time a couple of days later.

I'm also surprised it won't run without the MAP sensor, I would imagine most of the fuelling is handled by the MAF's.

I still totally do not get it, why the sensor had problems at the beginning, the car wouldn't keep running and swapping the sensor magically fixed it (to some degree).
I cleaned the original sensor and refitted it of course, with no success. Changing the genuine with the new cheap sensor was basically everything I have changed before the car ran again. The cleaning of the CSOV, throttle body, putting the throttle body flap back into place etc. all came after swapping the MAP sensor where the car had already run again.
I absolutely don't know what else caused the problems in the first place, but this didn't happen again.

Luckily I didn't throw away the genuine sensor, even though I thought it just had it.

Anyway, I want to thank you all for guiding and helping me narrowing down the problem! Your help and input is invaluable. I didn't see the the obvious difference in the readings and would have not suspected the new MAP sensor.

I will report back after my test drive today.
If the problem does not occur, I will probably leave the old sensor installed, still buy a new, genuine one and carry it in the car.

Cheers,
Matt

[DiscoJeffster]

Nice work buddy and nice work Shack diagnosing that discrepancy

[shack]

Nice work buddy and nice work Shack diagnosing that discrepancyCheers..

I'll save final comments after we get some more definite results!

But yeah, hopefully on the right track.

[Jeffoir]

You guys are amazing!
the diagnostics in this thread are impressive.
best wishes, Jeffoir

[mtthsk]

Hi there,

this afternoon I took the car for a good ride, driving it way more aggressive than I usually would. After warming it up for a bit, I went on the autobahn and directly when accelerating onto it the car pulled again like I used to know. I drove 160, 170 kph for 5 minutes continiously and everything felt really good. Also when overtaking I really put my foot down to also trigger the CSOV opening and the second air intake path. I logged the values and everything really looked as you would expect it.

It felt really good to drive the car without hesitation that it would go into fault when accelerating too fast. It is quite stupid that I had the old sensor still in the car the whole time and probably could have fixed it way sooner.

Still I don't know why the first problems appeared and what fixed them in the end.

However, I am very happy to have that car back to normal! I really like to debug this kind of stuff and do the repairs myself, but this really put some strain on me. Not being able to find the root of this much discussed problem with so many possible solutions. In the end it seems as though it was exactly what the fault code said: a general electrical failure of the MAP circuit, with its main part being faulty. I learn from this to not even exclude freshly swapped out parts from the diagnostics and to be rather sceptical at such low price parts.

And I learned lots about the car while trying to fix it, which I really love!

Anyway, I am so grateful for the help of all of you, love the community! If you wouldn't have helped me, I believe I woud have swapped the vacuum hoses next and after another disappointment would have brought it to a local Land Rover specialist. Maybe they would have found the problem, but reading all the stories that the workshops just swap the whole turbo rather than really diagnose the problem, make me more grateful that I dont need to book an appointment in the garage and spend thousands on parts that are still good...

For now, the old sensor seems to hold up, but as I cleaned it rather drastically I don't really trust it that much, so I still ordered a new, genuine one from the UK that is due to arrive in two or three weeks. If the old sensor fails, I can still install the cheap one and drive carefully without too much load [bighmmm]

Of course if the problem comes back in any way I will report back here!

Cheers,
Matt

[shack]

It refers to replacing the engine control module or map sensor as the resolution to inconsistent values hence I’ve inferred it.
I am still not sure where it’s getting the baro value from.Just revisiting this.

I haven't worked out where the atmospheric pressure is coming from, but it would appear a number of manufacturers do actually have a sensor on the ECU board, so what you have suggested is quite possible, or even likely!

[MauMan]

Hello Matt,
many sections of your story sounds very similar to my experiences I made within the last three month with my Disco 4 SDV6 and I also observe the P0105 MAP barometric circuit issue after MAP sensor exchange with TRISCAN after market replacement. Therefore I tried another unbranded after market sensor, but the DTC P0105 still remains. So I thought that this is common behaviour for after market products but the sensor in general is doing his job and is not the root cause for my the P1247 and P006A DTC's and the red rectangle of death in my display. But while reading the end of this thread I can imagine my assumption was wrong.
So if you have not suicides before you could write that your problem came back, I would be very interested exactly which MAP sensor you ordered and also, if allowed to write, where you have ordered it.

Thanks in advance
MauMan