Thread: Leak in EGR system - how to seal?

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.

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.

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/0f56...fXBvr4bQd6XmKA
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:

mapsensor2.jpgIMG_7795.jpg

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/09fj...1TitneyDfnLMiA

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/#087iE...DW-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:
IMG_7819.jpg
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:
IMG_7742.jpg
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

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

Originally Posted by 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

Thanks so much for your help!


I have measured the open circuit resistance of solenoids 7 & 8 in the following picture:
IMG_7802.jpg
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:
IMG_7837.jpg
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/0e0R...tSUFw4SpSD9EKw
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.
IMG_7873.jpg
IMG_7874.jpg
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

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.

Originally Posted by 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.

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..

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