1996 A6 2.6SE Auto Estate Cutting Out

[moose814]

Hi
My a6 drives like a dream, unfortunately over the last two or three months it has had a tendency of INTERMITTENTLY cutting out when slowing down at traffic lights, junctions, etc..
As it slows down to a stop the revs drop, sometimes they drop where it almost cuts out then recovers, sometimes drop so low it cuts out. This problem is only when engine is warm and not cold.
Diagnostics on engine is not showing anything. Diagnostic on gearbox picked up a fault on brake switch, replaced this but no joy.
Funny thing is, when the computer is conncted for diagnostics the car runs well for a couple of weeks then back to problem again.This has happened three times, too much of a coincidence?
Mechanic thinks it could be idle valve(sealed unit expensive) but cant be sure until fault is permanent. If it is the idle valve how does this explain the running well for a couple of weeks after connecting diagnostic computer?

Could it be an electrical fault, engine management, c.o. sensors, etc.?
Besides the cutting out it drives perfectly.
Very frustrating. Please Help!!!

[Kev.trebuan]

Not sure if it helps but I also have an engine cutting problem on my 2.0 8V A6. I Googled the part number of a relay that sends the lamda voltage to the ecu and found a load of incidents of MK3 Golf GTis with an engine cuting problem when the car is slowing down. The part is 165906381. If you Google that, you will find threads on other forums. Replacing this part appears to have woked with the Golf.

[moose814]

Not sure if it helps but I also have an engine cutting problem on my 2.0 8V A6. I Googled the part number of a relay that sends the lamda voltage to the ecu and found a load of incidents of MK3 Golf GTis with an engine cuting problem when the car is slowing down. The part is 165906381. If you Google that, you will find threads on other forums. Replacing this part appears to have woked with the Golf.


Thanks for that.

This sounds likely as it was more electrical than mechanical in my mind.

I'd hate to have paid for an idle valve, as local independant suggested.

Atleast if it is not this relay it wont be costly.

Thanks again and will try

[DurbanDriver]

Hi Guys, Have been pulling my hair out. Spent a fortune at Alpine Audi trying to cure cutting out at low revs problem. Replaced plugs, cambelt and lambda sensors. Car ran fine for a week and now it lacks power again - won't accelerate fast - and cuts out occasionally when slowing down. I found a worn vaccuum hose on the side of the throttle body. Car is definitely better, but still cuts out occasionally.
Did you solve your problem?

[DurbanDriver]

By the way, it is a 1997 A6 2.6 Avant if thats any help.

[sbt]

hi i had the same problem on a 1.8 20 valve a4 a while back it turned out to be the air mass meter just try unplgging it and see if things improve doing this completly solved my problem and by the way this problem never shown up on the diagnostics check

[acetaylor]

i had similar problem with my old audi 100 2.5 tdi.

bought new rubber injector pipes, changed them (easy peasy job)

this sorted the problem.

hope it is as simple as that!!

[DurbanDriver]

Hi acetaylor,
Sorry to appear ignorant, but where exactly are the rubber injector pipes? Mine seem to be all metal chaps?

[DurbanDriver]

Hi sbt
Does the car run properly with the air mass meter unplugged? Where do I find the connection?

[sbt]

hi yes the car runs ok uses more fuel i unplugged mine the car ran ok so i bought a new one off ebay 40 quid if i remember rightly it is found on the air intake pipe after the air filter it should have a plug underneith its about 4 inches long and made from black plastic hpoe this helps

[acetaylor]

this was on my old audi (early 90's!).

but they are located on the head just by the rocker cover, the cylinders and glow plugs.

not on the pump.

these pipes had corroded over time (and from using additives in my deisel!) when the revs were high fuel flowed through no probs, when they were low they got blocked and the car just stalled.

Hope this is more helpful

Cheerio

[DurbanDriver]

Thanks sbt. Will give it a try in the morning.