A4 2.6 rough idle/rough at high rpm

[teccyjim]

Having shifted the Bora and bought an A4 I have a problem all ready.

When you put the key in the ignition and turn on the electrics, the water temp, brake warning and oil pressure lights flash. (is this a way of getting my attention or is this normal?). When I turn the key the car the car starts briefly before cutting out, yet blipping the throttle remidies the problem....the car is now idling. Problem is it is 'stuttering' at idle and when moving, the car pulls fine although beyond 4000rpm sounds like it's vibrating and is reluctant to rev.

Any ideas? Help, as always, appreciated.

Jim

[snigged]

Hi Jim,

I have a 95 A4 V6, yes the lights flash. Do you have a orange circle with a key in it flashing?

These cars have a key recognition system. If the orange circle continues to flash then the key has not been recognised. The car will start and then stop.

For years I have been taking the key out turning it round and trying again. I'm thinking of selling my car so I took it to Audi.

Dear Audi charged me £120 diagnostic fee, a new coil £12.27 + £30.15 labour giving a grand total of £190.84 incl Vat

The bad news, if its not the coil they change the key, if its not the key they change the barrel and if its not the bareel the change the immobiliser. Yes you pay for ALL parts even if they are ok.

This is a start but not sure if its connected to the rough idling.

David

[teccyjim]

The lights issue is ok then.

I was thinking of going down the coil/sparkplugs/ht leads route and eliminate them all. its done 100k now so leads are probably due anyway. coil seems cheap!!!? my old MR2 one was over £60!!!

Thanks for your help.

[snigged]

Hi

Have you cleaned the throttle body as someone else suggested

David

[teccyjim]

no, not yet. ive got a day off tomorrow so will 'attack' it then. Out of intrest, what would lead you to belive it to be the throttle body at fault? At low rpm/normal driving it's really smooth. Surely a throttle body fault would make the engine rough through the whole rev range????

Jim

[snigged]

Hi Jim,

Cant find the thread now but someone else had this problem.
I printed off how to do it from

http://www.mobiloil.com/USA-English/...le_Bodies.aspx

David

[snigged]

Hi Jim

Engine throttle bodies; how-to article on cleaning them appearing on www.mobiloil.com
http://www.mobiloil.com/USA-English/.../Car_Care/DIY/ Cleaning_Engine_Throttle_Bodies.aspx - 38.5KB

David

[snigged]

Found thread, yes only rough idle
David


A6 rough idle

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Just in case there is anyone with an annoying rough idle/car cutting out when clutch is grounded - here is something that sorted it for me.

Clean the throttle body as coking builds up (apparently a common issue with WAG engines)

Runs nice and sweet now!!

Cheers

Evandar
2000 A6 1.8T Avant 60K

[teccyjim]

***UPDATE***

Haven't had the opportunity to look further into the problem due to work commitments, however...

Car took 5 attempts to start this morning and 4 attempts to get me home. Does this alter peoples' opinions on the fault at all?

Gonna grad my multimeter now and check resistance of all ht leads and coil. will also check condition of plugs.

I'd like to think it's the coil as its going down a similar route to the MR2 i used to own. Coil replaced- problem solved but as a bit of a VAG 'virgin' I don't want to jump to any conclusions.

Many thanks again.

Jimbo