TD5 Auto Question

[jadan]

Hi Guys, Great site and thanks for all info. I have just become the proud owner of a 2004 Discovery TD5 auto 250k`s. Great car but it seems very sluggish on hills starts. It gets to the point where i don`t think it will make it up the hill. Once the turbo kicks in at around 2000 rpm it starts to get going but before this its limited to about 5kpm! Is this normal? I have just come out of a landcruiser 4lt on gas which had a bit of go but this Disco seems Very slow of the mark. I have checked the air filter and it is clean. Any other suggestions? Thanks

[SiddersC]

How much throttle are you giving it?, they have a long stroke accellerator and you will have to put your boot into it a lot more than your petrol cruiser

Sounds about right, re turbo as it doesn't spool up until around 2000 rpm, coupled with the auto box they can be slow off the mark if you are not giving it the berries

[antond]

There is turbo lag under 2k (about 2200 is peak torque when you should really feel it kick in), but the auto box will mask this at lower revs. The raw capacity of 2.5 L trying to move 2.5 tonnes uphill means its relying on the turbo. The engine ecu will work out the fuelling and boost, but to really get going it seems to work this out better if you give it full boot from standing start rather than from rolling start or progressively increasing. If its really sluggish could be another issue. Inter cooler, pipe work or EGR could need checking?

[Xtreme]

Check your MAF (Mass Air Flow) sensor.
I had similar symptoms and a clean with MAF cleaner retured everything back to normal.

[jadan]

Thanks for your replies. I think you are right, mabye i`m a little too gentle! I will also clean the MAF and see if it makes a difference... cheers

[gazk]

If the MAF clean doesn't fix the problem, disconnect it and see if that makes a difference. If it does the MAF has probably failed. The MAF output can be tesed with a Nanocom or similar device.

[joe.woods]

I had the same problem it ended up being the oxygen flow/pressure sensor on the inlet manifold; changed that and it was a new machine...

[Franrick]

I am not disagreeing with previous comments but when I first got my D2a TD5 I thought it was a bit sluggish but when I 'learned' how to drive it it was a whole different vehicle.
I was initially very light on the throttle but I soon learned that a bit more of the right foot made a BIG difference.
Hope you sort it out. They are nice vehicles.

[OffTrack]

While the suggestions above are valid, don't fall into the trap of randomly replacing sensors in the hope that you'll fix a problem. It's a sure fire way to turn a Td5 into a money pit.

Have a look here and you should find a member nearby who has Nanocom:

https://maps.google.com.au/maps/ms'msid=218400750788295972519.0004d2028daa79a1b492 9&msa=0&ll=-27.432728,152.950287&spn=0.79592,1.319733

You'll have to send a PM via the forum to the name listed on the map to get in touch.

If you can prevail upon someone to check for engine fault codes, and to record fuelling inputs for a 5-10 minute drive you'll have a very good snapshot of whether the engine is running correctly. Members will be more than happy to help interpret the "tea leaves".

cheers
Paul

[carjunkieanon]

A few things I've learnt re a 2004 D2a.

1) It does need to be driven with a heavy right foot.
2) A genuine MAF unit works, a non genuine MAF doesn't. Don't know why. Learnt that from Davis Performance Landy.
3) I had power issues with mine for ages. MAF, EGR + still unknown, probably pressure switch. When I first bought it it would struggle to do 80km/h on the flat on the freeway, and might do 40km/h up a hill with a good run up. All sorted now.
4) It does have a limp mode which (as I understand it) can cut you down to low revs and speed to (I assume) protect the engine. This is reset by switching off the ignition. Recently after driving quickly up some very long steep winding hills, then driving quickly up some not so steep long hills, then a few more steep hills, all with good revs and now loss of power I suddenly found that when uphill, pedal flat to the floor it wouldn't rev above 3,000rpm and top speed was 60km/h (100km/h zone). At the top of the hill I pulled over, switched off, my wife took some photos and I let the kids stretch their legs. Restarted and drove off back to normal.

Have fun with your Disco.

R

[jadan]

Thanks everyone. I`ll clean the MAF tomorrow and see if it improves. If it doesn`t I`ll contact you Paul for a name. Thanks again, I`m loving it so far just not used to having to drive so hard.... cheers

[SiddersC]

You are probably not really driving it that hard, at 2500 rpm you should be taking off just fine at 3000 you should be flying, they will be a lot louder than the petrol motors at these rev range
Diesels do lack the initial poke of the petrol engines, but will keep pulling
They do take a bit of getting used to, but once mastered I am sure you will be very happy
See how you go, and as Paul said, get hold of someone with a nanocom to record some live data and check for faults

[SiddersC]

Also, a quick test of your MAF if you suspect it is to disconnect it and take it for a spin, if it is vastly improved your MAF or its circuit is suspect

[OffTrack]

Thanks everyone. I`ll clean the MAF tomorrow and see if it improves. If it doesn`t I`ll contact you Paul for a name. Thanks again, I`m loving it so far just not used to having to drive so hard.... cheers

Don't contact me ;) - have a look at the map I linked to. Find a marker or two that are close to where you live and click on them. That will tell you the members username and which vehicles their gear works with.

You shouldn't have to drive hard - 1,800-2,000rpm should be enough to get you moving. 2,400rpm is 110kph freeway cruising with torque convertor locked in top. 3,000rpm is really getting into "gunning it" territory.

One tip for hilly country - use sport mode. The auto will hang onto gears for longer before changing up which can help.

cheers
Paul

[phuma]

I use third gear in the passes etc. It locks up in third too and then it does not waste so much energy in the auto.

[mattyg]

The other question is does your disco have standard sized tyres. 235 70 16. Or 255 55 18. When I put bigger tyres on mine I struggled to get up my mildly inclined driveway from a standing start. Foot flat to the floor for about 2-3 seconds while the turbo came up to boost, then it was ok.

[jadan]

Hi, i cleaned the MAF and it did make a difference. Not huge but noticable. I am also putting a little more boot in to it and that makes a difference! I do have 18in wheels so this will make a difference as well. I went for a long drve and am loving it. Thanks for the info.... cheers:)

[Xtreme]

Hi, i cleaned the MAF and it did make a difference. Not huge but noticable. I am also putting a little more boot in to it and that makes a difference! I do have 18in wheels so this will make a difference as well. I went for a long drve and am loving it. Thanks for the info.... cheers:)

An easy job which I'd recommend you do each time you replace your air filter.

[PhilipA]

Funny, the one I have bought seems to have excellent takeoff .

It is a EU3 auto with the extra 40Nm but I was impressed with the meaty torquey feel. Almost as good as my Thor equipped 3.9.

I haven't had it over about 60Kmh though so maybe it will lay down on the first hill.
Regards Philip A

[eckolsim]

A few things I've learnt re a 2004 D2a.

1) It does need to be driven with a heavy right foot.
2) A genuine MAF unit works, a non genuine MAF doesn't. Don't know why. Learnt that from Davis Performance Landy.
3) I had power issues with mine for ages. MAF, EGR + still unknown, probably pressure switch. When I first bought it it would struggle to do 80km/h on the flat on the freeway, and might do 40km/h up a hill with a good run up. All sorted now.
4) It does have a limp mode which (as I understand it) can cut you down to low revs and speed to (I assume) protect the engine. This is reset by switching off the ignition. Recently after driving quickly up some very long steep winding hills, then driving quickly up some not so steep long hills, then a few more steep hills, all with good revs and now loss of power I suddenly found that when uphill, pedal flat to the floor it wouldn't rev above 3,000rpm and top speed was 60km/h (100km/h zone). At the top of the hill I pulled over, switched off, my wife took some photos and I let the kids stretch their legs. Restarted and drove off back to normal.

Have fun with your Disco.

R

Carjunkieanon,

Be careful, it sounds like your TD5 is getting too hot. You may need to check if you've done your gasket as these symptoms are similar to overheating. When the engine gets too hot the ECU limits the fuel.

[Nicky]

Carjunkieanon,

...... When the engine gets too hot the ECU limits the fuel.

Where is this from?

[OffTrack]

From the Owners manual:


1. Temperature gauge
Once the engine coolant has reached its normal
operating temperature, the pointer will rise to a
position within the WHITE segment of the
gauge (the precise position will vary according
to climatic conditions).
If the pointer moves towards the RED segment,
this indicates that the engine coolant is
becoming too hot. Should the pointer move
INTO the RED segment and the RED warning
light within the gauge illuminates, severe
engine damage could occur (under these
circumstances, the air conditioning may switch
off and engine performance may reduce in
order to minimise engine load).
Stop the vehicle as soon as safety permits and
allow the engine to idle for five minutes in order
to cool down - DO NOT SWITCH OFF. Seek
qualified assistance before continuing.


From RAVE:


The ECT sensor is located in the coolant outlet elbow on the top of the engine. It provides the ECM with engine coolant temperature information. The ECM uses this ECT information for the following functions:

Fuelling calculations.
Temperature gauge.
To limit engine operation if coolant temperature is too high.
Cooling fan operation.
Glow plug operating time.


Apparently there are a number of strategies employed including switching off cylinders so they only pump air to assist cooling the engine.

The red coolant warning light comes on when coolant temps get to 121°C.

cheers
Paul

[carjunkieanon]

Carjunkieanon,

Be careful, it sounds like your TD5 is getting too hot. You may need to check if you've done your gasket as these symptoms are similar to overheating. When the engine gets too hot the ECU limits the fuel.

Thanks for the advice. Temp needle sits pretty much at the 3o'clock position so (hopefully) not getting too hot, but it is chipped with a DPL chip and I know that can cause the heating issues. No whistling sounds and it's been to DPL reasonably recently. I usually don't push it too hard so will have to cross my fingers....pretty broke at the moment.

[wardy1]

Mate just replace the MAF. Seeing lots of posts here about cleaning it but really, it's the best $250 I've spent on mine. Better power, better economy (10% over 2500k's including a 700km low range bit). My only beef is that I didn't do it earlier:mad:

[OffTrack]

Like most things it will only make a difference if the MAF is shagged. There is a simple check you can do with a multimeter that while give a very good idea of whether its within spec.

Replacing bits without testing them first isn't a sustainable way to maintain these vehicles.

[Len]

Hi Offtrack how do you do this test please.

[OffTrack]

Type "MAF resistance" into the "Search AULRO ONLY!" box at the bottom left of the page.

The first result will point you in the right direction:
http://www.aulro.com/afvb/discovery-2/153274-maf-resistance-values.html

[bsperka]

I've been trying to assist with this one and we've had the nanocom on the vehicle. No faults read for the engine.

Symptoms: The turbo is very slow to spool up, which makes it feel like the auto is the problem. No major spool up, even after 1500 / 2000 rpm. Fuel related problem perhaps?

The MAF is ok'ish , as per our tests (we swapped it out for a good one) http://www.aulro.com/afvb/discovery-2/138749-td5-boost-modulator.html.

It may be the boost modulator - we need to try bypassing it, as per this thread. Even though we cleaned the sensor on the inlet manifold, we could also try swapping out the oxygen sensor, if you want.

BTW: Tests done to date: Oil in the auto is clean and to the right level or perhaps a bit high even.
The nanocom indicated the MAF was reading a bit low, but ok. No resistance tests done. We swapped it out for a known good one.
Wastegate works ok. Tested with a bike pump - actuates ok.
Cleaned the sensor on the inlet manifold.
ECU connector clean (no oil).
No FPR leaks.
Checked the turbo on the inlet - no play etc.

Any other thoughts on why the engine takes forever to spool up???

[OffTrack]

Record the fuelling inputs with the Nanocom and post the file up here. If you can do a 10-15 minute recording covering a section with a hill climb where you can really put the foot down and get the turbo on boost, or overloading you should get some useful information about what the engine is actually doing.

cheers
Paul

[joel0407]

Hey mate. Wondering if you found a problem or this is how they are.

Mine is the same. I have only owned it a week. I'm not sure if I have a problem or this is how they are. I have never owned a 2+ tonne automatic 4x4. I have only driven Manual 4x4s before. I wanted a Manual but couldn't find one with 7 seats.

On the Hwy it seems sweet. I haven't watched what RPM it's at but 844km took 87 Litres. Sat on 110km/h with out a worry.

It's up my slightly steep drive way that I notice it. Maybe I'm just not giving it enough berries. Seems to rev more than I feel is right without moving. It's just the slow take offs that I notice it. Stomp on it and it's nearly enough to light it up on dirt.

Driving my Skoda Yeti 2.0 TDI today with a trailer on. I hadn't realy thought about how well it goes. I've been really happy with it and got a surprise today when I went on the weight bridge at the tip at 2.5T. It really made the Disco look bad but then the Disco is 12 years and 168,000km older.

Happy Days.

[jadan]

hi, I have had some luck. I changed all of the boost hoses and it did improve quite a bit. I noticed it is much better when I don`t have the air on. As an aside, the vehicle is back at the yard under warranty and I have been told the harmonic balancer was gone. It sounded like the air-con bearing but luckily the mechanic persisted and came up with the answer. I have not driven it yet but hopefully will get it back tomorrow. Do you think the H-B would make a difference?

Cheers Tom

[PhilipA]

Mine is the same. I have only owned it a week. I'm not sure if I have a
problem or this is how they are

Both cars definitely have something wrong.

I have owned mine ( 2002 EU3)2-3 weeks now and the step off is really excellent on mine and slightly better than my V8 3.9 with unichip and Thor.

I am pretty amazed I have to say and mine is rock stock with EGR etc etc.
Up until now it would not rev out to 4200 , but today it fixed itself.

I cannot understand your reports on slow spool at 1500 -2000 as the TC stall is 2800RPM so the engine should shoot up to 2800 then up from there as revs rise.
I wonder if diesels are driven very slowly whether the ports around the inlets and exhaust valves get gunged up so much that the performance drops off, as a series of Italian tune ups worked for mine.
Regards Philip A

[2 rocks]

Hi Philip
That's interesting to know...

I actually agree with Jadan & Joel, the slow spool up on my '01 auto has dogged me for years (esp with the air on), and over that time has given me a few "frights" when it's been reluctant to move off the way I expected it should.

This has become particularly apparent to me since buying the manual a couple of weeks ago. I know that the manual is also chipped, though I have no information on what it is (the auto is 140kW), and it has a 3" exhaust - but the difference between the two is very noticeable. I have no hesitation darting across intersections I wouldn't contemplate in the auto. :(

Which begs the question, if others have a similar experience is it a turbo or fuelling issue or is it an issue with the auto. And yes, once you can get it up to 1800-2200 rpm it starts moving and keeps charging, but that space between idle and there can be black hole. What has me scratching my head is that sometimes I can put the pedal down and away it goes. Intermittent issues area nightmare!

Good luck with it Jadan! :)
Cheers
Mike

[Mikey]

G'day, maybe I can add my own experiences to this issue. I have a 99 series 2 TD5 auto and the only way to get it moving quickly (especially with larger tyres, 32") is to give it a big dose of right foot. Feels a bit like a slingshot at times. I have done a bit of work to my disco such as a ecu remap, vnt, larger intercooler, different exhaust and manifold etc., so it is producing a little more power and torque than standard these days.

If I needed to get across a busy intersection or get up to speed quickly, I have to think and react a second or two ahead of time to allow for the torque converter in the auto box.This, hopefully from all accounts will be rectified when I put a lower stall converter in it in about two weeks time, fingers crossed.

The box is out at the moment as the 1st planetary gearset one way clutch is u/s. It is one of the components that was "upgraded" supposedly 3.5 years ago during a ridiculously expensive rebuild (lots of $$$), ah if only I had shopped around. Hindsight is a wonderful thing.

So, if your engine is performing properly then I would suggest that it is the torque converter high stall that you are experiencing. There are discussions and information on the web about this and how opinion is that the stall is too high and converter too small for the TD5, especially a tuned one.

Cheers,
Mikey

[joel0407]

Thanks for you replies guys.

I'll report back once my Disco gets to Darwin and I get it registered and do a bit of driving.


Happy days.

[PhilipA]

I really doubt whether a low stall TC will help a TD5 get off the line quicker.

When pondering what could be wrong with slow pickup on the TD5 I got to wondering whether somehow a petrol TC had been substituted for the correct TC somewhere along the line eg at a transmission rebuild as the petrol TC has a lower stall than a diesel.

I mean drag cars have Hi-stall converters fitted to IMPROVE step off, and IMHO the same theory exists for the TD5. The hi stall converter is fitted to allow the TD5 to gain useful revs to get into the torque band.

Regards Philip A

[bsperka]

We finally got time to get the nanocom onto the vehicle and record the behaviour. The file is attached. Shows as an xls to get it to upload, but is actually a csv. What I find intriguing is that the air pressure is really saw toothed, rather than squarish. The wastegate is opening when there doesn't appear to be enough boost to demand this.

I have a comparative map from my vehicle on the same run (mine has a moded map, whereas the other one is assumed and appears to be factory map) and the sawtooth behaviour is major difference. The vehicle requires foot to the floor to get it to do this, whereas mine is 1/3 to 2/3 down to the floor.

To date, MAF has been replaced (already ruled that out by temporarily replacing it with mine, which is good), air filter replaced (but was still in servicable condition), cleaned IAP sensor on inlet manifold, EGR is removed, wastegate actuator has been confirmed as operational, although wound to 10 - 11 threads. The cat is removed but still the problem is there.

Any pointers on what to else may be causing the issue would be greatly appreciated.

[OffTrack]

The obvious things look alright to me:

http://www.aulro.com/afvb/attachment.php?attachmentid=58927&stc=1&d=1365741397

c11-c10 is manifold pressure - ambient pressure to give a plot of absolute boost.

The wastegate modulator is just controlling the amount of pressure that reaches the wastegate. It's designed to allow more boost at part throttle openings, but when the modulator is fully open the wastegate behaves as if it were directly connected to the turbo outlet in the same way as a Defender.

The airflow readings are basically following the boost curve which is what you'd expect to see.

There is definitely no overboost happening. You can spot this straight off by the recurrence of the 100.00 inlet pressure readings which I can't see in the recording, and you would also see a peak boost reading of around 21-22 psi. The highest in this recording is something like 16.8 psi.

The IAT reading looks very odd to me. It's seems too high and maybe a bit too static. From what I've seen I my d2 Inlet Air Temp varies quite significantly with boost levels. The reading is moving but it's in a fairly limited range.

This was from an input recording I did on the weekend:

http://www.aulro.com/afvb/attachment.php?attachmentid=58929&stc=1&d=1365743959

You can see how the IAT rises when the boost pressures climb.

The MAP and IAT are used in conjunction to calculate the density of the air entering the cylinders and are one of the most important sensors for correct fuelling. It would be worth temporarily swapping in the MAP/IAT from your D2 just to see if that makes an improvement.

The other thing to consider is that the intercooler may be partially blocked which is resulting in the elevated IAT temps?

cheers
Paul

[OffTrack]

Just a follow up:

http://www.aulro.com/afvb/attachment.php?attachmentid=58931&stc=1&d=1365745874

I found a section of the weekend recording that had the slower roadspeeds and stop start behaviour shown in bsperka's recording.

I understand what you mean by sawtooth. The boost and airflow are very slow to peak. I still think the sensors are probably reading OK with the possible exception of the IAT.

I'm fairly sure that the issue is in the intake tract rather than the electronics. I'd be looking for restrictions or leaks somewhere between the intake manifold and the air box.

cheers
Paul

[bsperka]

Paul,

Thanks for the quick replies. Each change made makes it spool up quicker, but it doesn't have "punch" when the turbo comes on, if that makes sense, due to the slow turbo build up. I'll see when we can swap out the IAT on the manifold. This was previously cleaned, but may be u/s. Intercooler clean - damn, that's a PITA, but one area that hasn't been tried yet.

An area that I don't want to consider from a repair pov, but what would be the symptoms if the wastegate was leaking when not operated - ie not letting boost build up. Possible?

In the end the car is obviously drivable, but not performing as it should.

BTW: Hoses are ok from visual inspection. Also, from what I've read, when they collapse the exhaust is black (ie over fuelled). No black, even with the accelerator to the floor.

[OffTrack]

It's a bit of a puzzle. Obviously if the modulator or hoses to the actuator failed you'd be seeing overboot so that eliminates them as suspects. I haven't had the "pleasure" of dealing with a wastegate sticking open, but you'd have to think that it would be slow to pick up boost, so it would be worth investigating. You'd also expect to get a bit of a whistle under boost if there were hoses leaking.

The 55-60 degree IAT is a bit of a concern. Unless it was 40°C or more when you were testing that looks like the intercooler isn't working efficiently. The only time I saw 60+ IAT on the weekend was on a reasonably steep climb (Girvans Cutting on the Calder heading south from the Castlemaine turnoff for those who know the area) where the engine was sitting on 14psi boost at 110kmh for well over a minute. Ambient temps were mid-high 20's. Even that kind of performance has got me looking at a bigger intercooler.

I think of two ways for the intercooler to not be dropping the temp sufficiently. There might be more. First is a clogged intercooler which would restrict flow and mean the intake air wouldn't be cooled as much as with a clean intercooler.
The other possibility is that there is a air leak on the outlet side of the intercooler which could result in a larger volume of air passing through the cooler and less temp drop. But really that is just guess work based on the observed temps and pressures.

Perhaps have a look at what the IAT was doing on your D2 on the run you mentioned. That should give you a decent reference point to compare with, and certainly a better one than my d2.

cheers
Paul

[antond]

Just a thought... What about throttle position sensor. TD5 is drive by wire, and I believe there are two derivatives of this sensor 2 pot and 3 pot for later versions. Nanocom should give sensor readings, or swap with working vehicle (provided sensor is same type).

[OffTrack]

Just a thought... What about throttle position sensor. TD5 is drive by wire, and I believe there are two derivatives of this sensor 2 pot and 3 pot for later versions. Nanocom should give sensor readings, or swap with working vehicle (provided sensor is same type).

The accelerator readings are included the recording that was posted up and reflect the throttle inputs that were described (i.e. flat to the floor to get boost to build up).

http://www.aulro.com/afvb/attachment.php?attachmentid=58940&stc=1&d=1365753982

As you can see it's taking something like 15 seconds from application of foot to the accelerator to reaching maximum boost.

cheers
Paul

[bsperka]

So I deliberately wound my wastegate out so that it would be in the semi open position, to see if behaves like Jadan's vehicle. Nanocom data capture isn't exactly the same, due to different maps, but the air flow is sawtooth on the Nancom compared to my baseline data capture. This is in line with the problem child.

Jadan is also either going to wind out the wastegate in line with my tests to see if the behaviour doesn't change much or just go straight to the possible culprit, a leaking wastegate valve, when time permits.

For others, TD5 wastegate - Defender Forum - LR4x4 - The Land Rover Forum (http://forums.lr4x4.com/index.php'showtopic=49533) talks about one way of freeing the wastegate.

[worane]

Has any one given any thought it may be in limp mode? Remember he is new to the car and has no prior experience with the beast.

[bsperka]

No M&S lights and no faults reported by Nanocom. Also works through the gears. So not in limp home mode. As indicated, deliberately opening the waste gate to make it leak gives similar feel in a good car.