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 !!?

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....