# 2.0 TDI - lumpy idle



## Karcsi (Mar 6, 2003)

I think there may be something wrong with the engine, so would greatly appreciate some input from those with a TDI.

Cold start, and the idle is as smooth as anything (850rpm). After the engine has warmed up, the idle becomes lumpy; meaning that the whole can will jerk slightly, periodically every 1.5/2 seconds (with a couple of small kicks in between). The hotter the car gets, after longer journeys, the lumpiness is more pronounced. It does not matter how I drive, the result is the same.

As a consequence, it also seems that fuel consumption is worse for longer journeys, as the engine warms up (that's by resetting the trip to try and compare like with like).

On a shortish round trip, I can easily obtain well over 50mpg. Anything longer, and it's down to 47/48mpg even with a light right foot and 'A' road driving at 60mph. With my parent's 1.9tdi 130 that would be easily 55mpg+.

I might ask Audi to take a look when I take it in for the locking wheel nuts to be fitted. But that depends on whether any of you (or indeed 1.9tdi owners) have experienced something similar. Also, I might hold off for another couple of thousand miles to see whether it sorts itself out (I've only done 2000 so far).

My parent's car developed something similar a year or so ago, and Audi fixed it (I think with new injectors, but not sure). But I never experienced it myself, so don't know how the symptoms compared with mine.

Cheers


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## aThreeUK (Aug 11, 2003)

I've not noticed any lumpy idling.

Having just done around 3200 miles I'm getting around 52/54 mpg on a 60 mile journey - mainly motorway at 75mph. Most I've had on the motorway was 58 mpg but that was doing around 40mph in too much traffic on the M6. The overall mpg (#2 on the DIS) is 50.9

Only had one problem up to now - front windscreen wipers failed whilst driving. It may be a generic problem as another guy on another discussion group had exactly the same problem - they took their car to a dealer but has yet to post the reply as to what was the cause.

For me luckily I was fairly close to home so managed to drive home without wipers and call the RAC. When the problem happened I switched everything off, ignition off and on again but still no luck with the wipers. Other things worked OK like the rear wipe, and front washers, but no front wipers. Only when I got home and the RAC attended did they spring back in to life with no help from the RAC. Only difference to being on the side of the road was locking and unlocking the car. Some electronics obviously got confused somewhere.

I've not yet taken it to the dealer (was hoping the other guy would post something before I went) as they are fine now and the chances of the dealer finding anything is probably quite remote - unless somebody knows such failures are recorded in the computer? The RAC guy who I called didnt think it was stored, it wasnt in the old style A3.


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## Karcsi (Mar 6, 2003)

Thanks aThreeUK.

Just did a 50 mile round trip to Cambridge. 54mpg average there and back - no difference cold or warmed up. Idle was lumpy by the time I got to Cambridge though.

My DIS shows 47.5 average for the 2000 miles I've done, which is about 75% motorway driving (80mph mostly) and A roads (65 mph mostly). But I doubt that is representative, because my foot has been a little enthusiastic ;D.

I feel perhaps mpg isn't affected as much as I thought. A little more experimentation is required.

What is your idle speed? My father is surprised that mine is only 850rpm compared to his 950rpm.

On the wiper side, at the weekend it did trip up for a split second. When I switched it from intermittent to continous it stop for a second or so before restarting again. I wonder whether it's got something to do with the speed sensor which switches it between the two modes. I'll keep my eye on it.


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## aThreeUK (Aug 11, 2003)

I'm sure the MPG will improve over time, its still a new engine at 2000/3000 miles. It looks like the idle speed is about 850.

For the wipers mine has a split second "think" when I push the stalk down for single wipe - but when they stopped completely changing from intermittant to full I thought a fuse had gone. Not great when they work OK now - perhaps the onboard computer use Windows 98 and it needed a good reboot?


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## coupe-sport (May 7, 2002)

The old 1.9 was a bit lumpy at times too - i dont worry about it now. Dont worry about the fuel consumption - gets better and better as it beds in.

James.


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## Karcsi (Mar 6, 2003)

Thanks James. I will see how it behaves over the coming months. After all, there's no rush: another 34 monthg to run on the warranty!


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## AudiYaLikeIt (Dec 20, 2002)

Experienced the lumpy idle this morning.
Could feel the whole car shake every 1 or 2 seconds; first time that I've noticed it, will take it back to the dealer if it persists. It felt, in petrol engine terms, like a misfire - don't tell me they've managed to introduce the diesel equivalent of the 'coil pack' problem?!


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## Karcsi (Mar 6, 2003)

Spot on. That's what I have.

While cold, the engine is fine. It occurs only when the engine has properly warmed up - after about 10 minutes or so. It's worse on some occaisons than others - like someone giving the car a knock every second or so

I'm going to speak to my dealer tomorrow and see what they say. My father has confirmed that his 1.9 did behave like this, and was caused by some fuel feed problem and was sorted. But I would not be surprised if their response is that it's a "characteristic" of the 2.0 TDI - i.e. it's not quite as refined as the 1.9 nor as refined as they claim!

Have you noticed anything with the clutch/transmission on these cold days? A grinding noise of sorts when changing gear (like the release bearings not being fully lubricated) until about 15-20 minutes into a journey?


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## Karcsi (Mar 6, 2003)

Spoken to my dealer. Tech guy said that these engines are quite tight when new, so I advised me to give it another couple of thousand miles before taking it in for a butchers. That was my first thought, so I'll wait and see.


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## Broad_Marsh (Nov 20, 2003)

Hi everyone. I joined this forum after looking at all the other Audi related ones as it seems more civilised and I have just purchased a new Audi A3 Sport 2.0 litre Tdi, after owning Golfs since 1982 (sad I know), with the last one being a chipped S Reg 1999 Golf GT Tdi 110.

I am also experiencing what seems to be termed lumpy idle by some people when the engine is at its normal operating temperature. I would term it a misfire if it was a petrol engine. There is not a lot more to say on the subject at the moment, as I have only covered 1600 miles. My initial observation is that it does not do it when the engine is cold, but once I have driven some distance and stopped and sat in a quiet location I notice it. I have not considered it too much of an issue yet, as it does not do it under load.


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## spiderman (Jun 7, 2003)

mine does it as well (now done 5000 miles) but I just assumed that it was a 'normal' diesel thing - can't say that it bothers me too much

incidently, MPG and performance is noticably improving with the added miles

the traction/stability control is really coming into it's own at the moment - inspires real confidence


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## Karcsi (Mar 6, 2003)

Welcome Broad_Marsh. Nice to see another TDI owner on here.

Seems like it is a "characteristic" of the engine. But it is something that just should not happen. All we can really do is stick with it and see whether it will smooth out with age.

From new I have always had the feeling that when coasting in a high gear there is more resistence (engine braking) than there really should. Perhaps this is also attributable to a tight new engine.


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## dynamodollishill (Jun 29, 2003)

Either I'm lucky or else this is due to come to me but I've never had the 'lumpy idle' experience.

So it doesn't affect all engines. I wonder if there is some cross reference to when the cars were delivered and those that have this problem (mine was mid Sept.). Just a thought.


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## Broad_Marsh (Nov 20, 2003)

Hi Karcsi

Thanks for the welcome.

You said
"Seems like it is a "characteristic" of the engine. But it is something that just should not happen. All we can really do is stick with it and see whether it will smooth out with age.

From new I have always had the feeling that when coasting in a high gear there is more resistence (engine braking) than there really should. Perhaps this is also attributable to a tight new engine".

I think it is all down to the ECU maintaining the engines fuel air ratio so as to make sure the engine runs within the latest emission limits. As you are probably aware, this engine is one of the cleanest on the planet.

Your coasting comment leads me to think along the same lines! I am not sure where I read it, but on my previous car 1999 Golf GT Tdi 110, I understood that when you take your foot of the throttle, the ECU cuts all the fuel off until it was down down to idle RPM. This not only saves fuel, but reduces emissions and of course makes the engine act as a brake. IMHO my brand spanking new machine does not slow down anymore or less than the Golf Tdi.


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## Karcsi (Mar 6, 2003)

I got mine first week in September.

As I was writing it, I was thinking it's probably more a ECU think than mechanical that's causing the lumpiness. It was a fuel feed problem that caused by father's 1.9 to do the same thing. On the mechanical lines, I was thinking that as things warm up, perhaps they get tighter. Although the opposite is just as likely - just depends on the comparitive composition of the materials.

I noticed the switching on/off of fuel with my father's 1.9. When just drifting along at 10-15 mph (middle of night when it's nice and quiet) you can really hear the engine almost switching on and off as you play with the throttle.

[I think modern petrol engines do the same thing. My Uncle regularly takes his car out of gear and coasts to save fuel. I've always thought that to save fuel you just stick it in a high gear and take your foot off the throttle. If you take it out of gear, fuel has to be feed to the engine to keep it going (at tickover), if it's in gear the motion of the car will keep it going without the need for fuel.]

So there is nothing different with this engine from the last. I just wonder whether the running gear is tight at the moment, so there's more resistence in it. My father's car seems to coast much more easily, and the engine spin much more easily. Although his has almost 20k miles on it.


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## Broad_Marsh (Nov 20, 2003)

> I got mine first week in September.
> 
> As I was writing it, I was thinking it's probably more a ECU thing than mechanical that's causing the lumpiness.


Agreed. I had noticed it in the first 2 weeks (bought mine 16 October), then forgot about it, as I always switched the engine off with the radio still playing that masked any noise or feedback through the bodywork structure. I checked last week and it did it once and then again last night when it didn't do it. Going back to my earlier days on military aircraft engines where the ECU uses air and other coolant temperatures to adjust the fuel, I would not be suprised given the level of sophistication used in modern cars that we are experiencing this automatic fuel/air ratio correction. I would not be suprised if you asked some dealers this question, that they would stick the car on the diagnostic machine and say that it is ok, as there are no error codes being displayed. What say you?


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## Karcsi (Mar 6, 2003)

You could be right, especially if it does not play up while it's on the machine!

Considering the engine fires more than 10 times a second even at idle (a quarter of that per cyclinder - is that right?), I would think that the changes in air/fuel mixture to keep the engine as lean as possible would be more subtle. I doubt that the quality of the fuel/air changes that much from cycle to cycle to require the air/fuel mixture to change so much that it makes the car jolt.

I wonder whether it only starts messing around with the air/fuel mixture once the catalytical convertor is up to proper operating temperature.

However, I am sure the misfires repeat in a set rhythm, and seem to oscillate in strength in a cycle as well. If it was just the the air/fuel mixture changing in relation to feedback from various sensors, it would be more random.


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## djtwright (Nov 23, 2003)

Good to see that others are experiencing the same lumpy idle as I have found on my 2.0 TDi Sport

Given the general consensus seems to be wait and see if it sorts itself out - then I will do (esp. seeing as I only got it on Friday)


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## Karcsi (Mar 6, 2003)

Someone on a german forum has said that the lumpy idle is due to a software fault which is due to be rectified in early 2004.

http://babelfish.altavista.com/babe.../www.motor-talk.de/t205468/f160/s/thread.html

That would make some sense if it was a software glitch messing up fuel feed. I'll ask about it when I next visit the dealer in a couple of weeks.


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## Karcsi (Mar 6, 2003)

According to the same chap on the german forum, the software update has been approved and is available from dealers for upload.

http://babelfish.altavista.com/babe.../www.motor-talk.de/t209924/f160/s/thread.html

I've yet to see my dealer. Sometime over the Christmas hols.


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## aThreeUK (Aug 11, 2003)

I noticed this the other day whilst stuck in traffic lights after leaving the motorway - anybody had this resolved by their dealer?

Checked with Audi UK (whilst chasing the wiper problem) about this "patch" but they're not aware of it.


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## Karcsi (Mar 6, 2003)

Maybe it's just the cold weather and the shorter runs I'm doing lately, but mine has done 3500 miles, and it doesn't seem to be as bad.

I also asked ACS and drew a blank. I have to pop in to my dealer over the weekend to pick up some touch-up paint (scuffed front spoiler underside on a "high" kerb - ouch), so will ask them. Could be the same as everything else: unless you have a serious problem with it and complain hard they will Audi UK will not want to fork out for a fix. Same with the wipers.


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## aThreeUK (Aug 11, 2003)

Mine now has just over 6000 miles and whilst it's not something that I'm worried about, now I know its there I can feel it sometimes and if there is a fix for it then would be good to have it. I'll get the dealer to have look when fixing the wipers, whenever that will be.


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## Guest (Jan 20, 2004)

I got the new A3 2.0 TDI, and I know where you are coming from, you are correct by lumpiness.

But its nothging that you notice unless your really sitting there to criticise the car itself. Yes I had a rattle on dash but is intermittent, and has no gone completely.

DAve


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## Guest (Jan 26, 2004)

My Golf 1.9 tdi does the same thing. When you come to a stop at traffic lights etc it feels like someone has swopped the plug leads round if it was a petrol car. I am told you will need to richen the mixture via vag com or risk the dealers!!.


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## Karcsi (Mar 6, 2003)

ogo1, I think you're right. When it's cold, the engine is provided an enriched mixture anyway, so you don't feel it. But when warm, the mixture is probably too lean.

I have spoken to my dealer. It's true, the Germans do already have a software upgrade for this and he is expecting that they will be able to get their hands on it within the next month.


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## Wolverine (Dec 22, 2002)

> ogo1, I think you're right. When it's cold, the engine is provided an enriched mixture anyway, so you don't feel it. But when warm, the mixture is probably too lean.
> 
> I have spoken to my dealer. It's true, the Germans do already have a software upgrade for this and he is expecting that they will be able to get their hands on it within the next month.


Karcsi, have you had the lumpy idle sorted yet?


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## Karcsi (Mar 6, 2003)

No, not yet. First I have to get the dealer to sort out the scratch they kindly added to my car before asking about the patch again. 

I'll keep you posted.


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## Karcsi (Mar 6, 2003)

Spoke to my dealer today. Yes, they have the CD with the update software. But, they have lent it to another dealership. Eh?!! Why haven't Audi UK/D sent every dealer a copy.

He said to give them a ring on Friday, as the CD was meant to be in the post back to them, so they might be able to do the update at the weekend.


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## Wolverine (Dec 22, 2002)

> Spoke to my dealer today. Yes, they have the CD with the update software. But, they have lent it to another dealership. Eh?!! Why haven't Audi UK/D sent every dealer a copy.
> 
> He said to give them a ring on Friday, as the CD was meant to be in the post back to them, so they might be able to do the update at the weekend.


Unbelievable! Hopefully they'll sort it out this weekend. I'd be interested in your feedback with the new software (when you get it installed)


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## aThreeUK (Aug 11, 2003)

Had my wipers fixed today, and also said about the lumpy idle. Dealer said they dont yet have a fix for it, knew nothing about a CD or update but said that it was something Audi are trying to sort out.


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## Karcsi (Mar 6, 2003)

Typical Audi: Arse? Elbow?

The fix arrived with my dealer a little over a week ago, and they have known that they were getting it for over a month.

Mine's booked in for the 26th to be done - it had to be a weekday (so that they can connect the car to HQ via the telephone if it goes tits up!), so that 's the earliest I can do.


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## aThreeUK (Aug 11, 2003)

Typical. Looks like I'll try again towards the end of the month - maybe they'll know more then. If you manage to find out exactly what your dealer is doing (update references?) then I'll see what my dealer says about that.


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## Karcsi (Mar 6, 2003)

Got the software update done yesterday. Initial impressions are that it's solved it! But I've yet to test it out fully.

What's interesting to start off with, is that the idle revs have dropped from 875 to 825.

The dealer seemed a little sceptical about my reasons for wanting the update done. I wonder what other things this update does, as I'm sure the idle problem is just one element given the dealer's reaction; he didn't appear too confident about it solving it, like that's not the main reason for the update being issued.


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## 03Dlava (Apr 16, 2004)

Karcsi, any further details on that software upgrade I can point the service guys over here to?

They haven't heard of it yet, but they haven't sold too many 2.0 TDIs either....


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## Karcsi (Mar 6, 2003)

Sorry, I don't know what the part number is, but dealerships should have access to the CD by now. Phone around if you have more than one dealership near you - it doesn't matter who does the update, as it's done under warranty.

It has definitely worked though. Idle as smooth as a baby's bottom now.


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## djtwright (Nov 23, 2003)

Glad to hear that your upgrade has sorted the idle problem out Karcsi. I've got mine booked in for this coming Friday - so hope that it sorts my TDi out too.

As for the part number, my dealer did mention a part number last Thursday once they'd done the diagnosis, so I'll see if I can get the part number off them... They did mention that the new A3's are a big learning curve for them (read in to that what you will...)


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## delarge (Nov 3, 2003)

I had my A3 delivered at the start of the month , would this upgrade have been done before it left the factory or should i push for it now ?

Idle is a touch (and i do mean a touch) lumpy , slightly worse when warming up (after the needle has started moving)


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## Karcsi (Mar 6, 2003)

I would have thought it would have the upgrade - it came out in Germany in late December, so I would expect all cars built in 2004 would have the update. Then again, depends on where in the process the ECU gets "built", and how much of a stock of chips they had with the old code.

For the me idle was very smooth when cold, but then became very apparent once the engine had warmed through - with the needle moving slightly on occaisons.

It could be that yours did not come with the upgrade. I'd suggest that you go to the dealer and just say that yours is lumpy and you know that there is some new software that eliminates the problem. Leave it up to them to discover whether it already has it or not. They may tell you straight off from the VIN number.


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## djtwright (Nov 23, 2003)

Latest in the saga - some good news and some bad news...

The good news is that for all of you out there that may have this problem with your cars, the Audi part number for the CD that contains the fix is 8Z0906961.

The bad news is that although the garage seem to have tried valiently all day to get the upgrade on (an it seems that they have spoken to everyone and their dog in the process) the upgrade resolutely refused to go on to my ECU, and hence the garage are going to replace the ECU in my car.


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