EGR valves and economy ?

[cjboddy]

Hello....

I posted a reply in another thread today re engine judder on idle, and the fact that my local audi dealership replaced the EGR valve and appeared to have fixed it.

Well yes the car has no judder now, but the economy has fallen seriously, about 10 mpg. I'm going to call them in the morning, but surely the replacement of this valve shouldn't impact the cars economy like that !!?:aargh4:

Cheers.

2006 Audi A4 Avant SE 2.0tdi 48k

[jez_h]

I've just bought an A4 2.0 TDi 140ps avant S-line, 2006 with 61k on the clock.

I've got a bit of an uneven idle, makes the car shake a little - is this the symptom you had?

I'm getting about 38-39mpg - I thought this was pretty poor really - book figure is 44mpg. I was driving very gently (75% on the motorway) to get 39mpg as well... What mpg did you get and what do you get now?

Sorry I can't help - just wondered if my idle and mpg is related at all.

[cjboddy]

Hello,

Yes that's the symptons I had, only seemed to do it once up to temperature. Much better now but still seems to have a slight shudder. At the moment I'm running a couple of tanks of fuel through it to see the results and then I'll prob return to the garage to check on the poor eco and the slight shudder that remains.

I got my 40mpg and a good eco run and couldn't drive any better so I'm not happy with that at the mo. I can put up with mpg in the 30's round town, but I was hoping to be in the 50's on motorway cruising.

Cheers.

[Audi_Convert]

Audi A4 2005 Avant 2.0 TDI.

Hearing this time and time again on the forum, engine judder at idle. Same issue here. Out of warranty now, said they couldnt find anything wrong. Typical.

I've been consistantly yielding over 40mpg (43 past few tankfulls) due to coasting in gear when possible. Pulse driving I think its called. NO hard accelleration i.e. going over 2000 revs when pulling away.

My mpg was always poor too. 38 tops. Had a remap, stayed the same. Started coasting/pulsing. Over 40 is a win.

On my TD5 defender I removed the EGR and it runs like a dream. I asked a question on here regarding its removal on the A4..... didnt hear much positive feedback. Surely you can.... Less exhaust gasses reintroduced into the cyliners the better in the Land rover world....

[c4a5er]

I'd be interested to know whether the EGR valve can be disabled also.

We have a TD4 with BMW m47 engine and the inlet manifold gets really choked with a build up of gunge from a mixture of oil vapour and exhaust carbon that affects performance noticeably.

Anyone know whether Audi diesels suffer from this?

[Audi_Convert]

We have a TD4 with BMW m47 engine and the inlet manifold gets really choked with a build up of gunge from a mixture of oil vapour and exhaust carbon that affects performance noticeably.



Tell me about it. When I removed the Defender TD5 EGR valve (29,000 miles on the clock) it was clogged to hell. Disgusting. Can't help but think the Audi's the same.....shivers like a shi**ing dog when stationary....

[jdk]

I have an 05 A4 Avant 2.0 TDI with exactly the same symptoms, the whole car shakes randomly when idling, i read many threads on the same subject but nobody seems to have a definitive answer, some suggest that it's a problem with the in head injector wiring, others the DMF and as with yours the EGR valve. Mine is telling me it's doing about 46mpg.
There must be a solution as it's such a common problem.

[Audi_Convert]

A total removal of the unit would be great like on other vehicles. Our vehicles shouldnt shake when idling. No diesel car I've EVER owned does that. My defender Td5 which is tractor status compared Audi ticks over better and smoother. Pathetic.:zx11:

[sambuka187]

Well thought I would chime in here as I am experienceing the exact same problem on my 2006 A4 Avant S-Line 140.

Its not the revs as it is ticking over fine, its the very noticeable judder once the engine seems to have warmed up.

Someone mentioned it might be the A/C but turned that off and its exactly the same.

Such a shame as I really like this car although this judder needs sorting.:zx11:

[Audi_Convert]

It's still annoying isnt it....however I do take some comfort in knowing that its not just my Audi.

Like I posted on another thread, when taken to Audi when under warrantly I got the "Computer sez no" feedback when under diagnostics. Yeah, so what mate. I dont give a **** what a computer says, how about some human physical feeling when sat in the car and a manual check. So frustrating.

I think most threads narrow it down to the the fuel filter/EGR iirc.

[cidge]

Hi I have Golf GTTDI 2.0 140, and I also get juddering at tickover sometimes, I also have a fluttering or air intake after a hard rev when slowing down again. Took it to diesel specialist and they are thinking down the road of needing a new turbo!!!? They originally suspected stepper motor on air butterfly, but that's ok. I'm taking it in to VW to have ECU update for recall on these engines, but think I will have the EGR apart to see what state it's in after. New turbo's are around £700-800.

I found when I took of the vac pipe to EGR the engine ran much better.

[c4a5er]

It's still annoying isnt it....however I do take some comfort in knowing that its not just my Audi.

Like I posted on another thread, when taken to Audi when under warrantly I got the "Computer sez no" feedback when under diagnostics. Yeah, so what mate. I dont give a **** what a computer says, how about some human physical feeling when sat in the car and a manual check. So frustrating.

I think most threads narrow it down to the the fuel filter/EGR iirc.

I've been running with EGR disabled by removing and plugging the vacuum pipe for a few hundred miles now without any negative effect so i'm going to leave it that way. I'd just rather all the exhaust sh*t go into the exhaust. As for what he computer says, VCDS shows no faults...:rolleyes:

[blknight05]

Hi i have the judder plus now the car wont rev.i had to get towed home so now without a car.my mechanic held the egr valve open which solved the problem.a new valve is almost 300£ and so am wondering if removing this vacuum pipe wil get me back on the road.where is it?