Do i Have an Engine Management Light? Erratic Idling?

[H17E5H]

Hi,

I recently bought a 1998 Audi A3 for my other half as a get to and from. However, when the car is idle-ing the rev counter starts to fluctuate between 800-1000rpm and a couple of times it has sounded like it is about to cut out. I've given it a full service including all filters (air, fuel etc) and spark plugs, thinking a good service would rectify most of the problem i.e having no restriction in air or fuel and having decent spark plugs for good ignition, however the problems still continues and is sometimes very noticable once the engine is at operating temperature. I've spoken to a few people including techies who said it could be the air flow meter so i replaced it with a original Audi air flow meter only to discover the fault still exists.
A friend had it put on a diagnostic machine for me but no faults existed in the engine section. I then quired if my vehicle would have a engine managment light but no one knew so we disconnect the air mass sensor and camshaft postion sensor hoping this would bring on the light but no light showed?

Just wondering if my vehicle has a Engine Management Light and what could be the cause of the idling problem? The car has one of the earlier instrument clusters without the LCD drive information system (DIS).

Thanks.

 

[Tastyterrier]

Try cleaning the throttle body, I had the same problem on my old 98 A3 1.8T and a good clean sorted it out.

 

[Wak-VAGCHECK]

Try listening to the engine around the inlet manifold, can you hear any hissing at idle?

You may have a leak in the vacuum side, i.e. the pipes that come off the manifold.

 

[H17E5H]

Hi,
Thanks for the replies. I forgot to mention i cleaned the throttle body and taught it in using diagnostic machine, the problem was still there and very noticeable.
I've tried listening to the engine especially on the inlet side a few times but don't seem to hear any leaks.

Any other suggestions?

 

[Tastyterrier]

Try following the oil breather tubes from the bottom front side of the engine to the inlet manifold with your hands rather than listening, feeling for holes all along. These tubes are particularly susceptible to damage due to the hot oil/air mix weakening the walls. A good clue of this problem is a strong smell of hot oil when the engine is fully up to temp.