Audi A6 Avant - 2.5 TDi Auto losing power on gradients - help!

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Thu 10 Jun 2010 11:59
Audi A6 Avant - 2.5 TDi Auto losing power on gradients - help! - Hemeloid

I have an Audi A6 Avant 2.5 TDi Auto 59,000 miles in great general condition and recently serviced. For some time I have been worried as the car will not go up anything remotely resembling a gradient. It will drive very well, quietly and at high speeds on a flat motorway. However, as soon as we get to a gradient the speed starts to drop. I have tried to clean the engine out with 2 tanks of diesel with a cleaner additive. This has had the result of the engine becoming slightly quieter and the INSP display now comes on after the second additive.

I cannot get the revs past 3500 which now makes me suspect the engine rather than the gearbox. I recently had the gearbox drained and flushed and new auto gearbox fluid added. The gearbox changes up and down appropriately. Also as far as I can see, the cambelts have not been changed - could this be the source of the problem?

Also I drive 5 miles to work and back for three daysa week and once a week do a motorway trip of about 50 to 100 miles. Am I clogging the engine up?

Any help or suggestions would be gratefully received. Many thanks.

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Thu 10 Jun 2010 13:24
Audi A6 Avant - 2.5 TDi Auto losing power on gradients - help! - Collos25

Its going into limp home mode. Common problems on the A6 diesel is the egr valve which I think is built into the manifold an expensive repair it needs looking at by a proper injector/turbo/pump specialist,the last one I did it was the egr and I will not do another.

Complicated machines need expensive repairs when they go wrong.

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Thu 10 Jun 2010 13:36
Audi A6 Avant - 2.5 TDi Auto losing power on gradients - help! - Hemeloid

Thanks for the information. The A6 does not continue with no power once we get over the top of the hill it will accelerate ok. It seems to be hills/gradients that defeat it. The fact that the revs won't go past 3500 suggests a valve/breather tube maybe?

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Thu 10 Jun 2010 17:04
Audi A6 Avant - 2.5 TDi Auto losing power on gradients - help! - Collos25

Yes thats what they do

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Thu 10 Jun 2010 17:49
Audi A6 Avant - 2.5 TDi Auto losing power on gradients - help! - corax

Look at this

http://www.audi-forums.com/c5-forum/43980-powerloss-a6-2-5tdi.html

It may be your problem.

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Sun 13 Jun 2010 23:10
Audi A6 Avant - 2.5 TDi Auto losing power on gradients - help! - Hemeloid

Thanks for all the info folks. Well, I decided to take it to a VAG specialist and they hooked the A6 up to a diagnostic system for £45.00 (refundable after repair) and diagnosed a dead Airflow Meter. I looked up on internet and decided to go ahead with replacement rather than clean it on a 12 year old car. Result is for £125.00 inclusive I now have a car which goes like a "stabbed rat". (c) James May, Top Gear.

I did talk to Audi who wanted to charge me £125.00 an hour labour to diagnose the problem. Then I'm sure they would have fixed it, but not having bottomless pockets, I was worried about the eventual bill.

I came back from Kent today with about a ton of wood in the back and roared up the hills at motorway speeds with no problems at all. Very happy with the end result!

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Sun 13 Jun 2010 23:11
Audi A6 Avant - 2.5 TDi Auto losing power on gradients - help! - Hemeloid

Lastly, the INSP light is still on. Does anyone know how to reset it, please?

Edited by Hemeloid on 13/06/2010 at 23:12

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