Erratic idle '99 Audi A3 1.6L

[gtorrens]

Hi,

When my car is idling the car judders and revs up and down. This apparently is a know problem with the Audi A3 yet no mechanic has been able to cure it for me. I've recently had the throttle head cleaned but it has not helped. Is there a fix for this or is it just how Audi A3's are? Any advice would be greatly appreciated!

[boss]

Read this, The Audi A3 has an engine code of AKL, This engine did not idle perfect coming from the factory, Because the engine design is very old it does not adapt very well to thelean burn needs of todays european emmission regulations, But you definitely seem to have a problem,

The inlet manifold on the A3 is of a Banana type ans regularly the seam on the inlet manifold seems to part after a few years due to exessive underbonnet temprature, the manifold is of a plastic material.

A dirty throttle body cannot and stress that cause rough idle, maybe cause fluctuating idle speed but not roughidle,

You will find that while waming up the engine behaves good until optimum running temprature is reached, then the fueling parameters of the engine lean off a lot and it the seam in the inlet manifold is drawing in air it willl probably make one cylinder run a little lean causing shuddering and wont show any problems with a gas analyser etc.

I would save your pennies, price a new manifold and consider having a new one,

The A3 is a damn good car and are a credit to the good breeding of the Audi brand.

Hope this is of use to you and keep faith with your car.

Regards Boss

[gtorrens]

Thanks for that! You're right about the engine performing good until it has warmed up. Also another thing i've noticed now is that when i ease off the accelerator the car chugs or jerks slightly. Is this a related problem? Maybe the mechanic has wrecked my throttle body when he cleaned it? I'll definitely look into getting a new inlet. I haven't lost faith in the Audi, I've just lost what little faith i had in mechanics!