AntwonJenkins

Hey everyone,

I have a 98' A4 2.8 quattro and Today after I added some oil to it (1/2 quart, and she needed it, dipstick showed oil level was Juuuust above minimum) I noticed an odd howling noise coming from my engine bay. The howl comes in intervals of about 5 seconds and lasts for 2-3 seconds before fading away and returning. I tried to pinpoint where in the engine bay the noise is coming from but to no avail. I can only hear the noise at idle. I have no clue if the car is making the noise while moving, but it is loud enough to be audible from inside the car. The car runs and drives normal, however. I drove it about 20 miles with zero problems. As a matter of fact the CEL went away after I added the extra oil. I'm not sure if this is a serious problem since the car is running normal, but the noise is concerning me since it started directly after I added the oil. any ideas on what it could be? BTW its been below freezing these past couple days in NY, but the noise was still occurring when the car was fully warmed up.

Thanks.

Articus

It's possible that it's the secondary air injection pump you hear. The pump adds air to the exhaust stream to reduce emissions. As it get's colder (catalytic converters don't work well until they are warm) i believe it's more likely this pump will run especially at idle when the engine is not warm and engine compensates by running rich fuel mixture.

AntwonJenkins

Thanks for the reply Articus, but it seems that the noise has disappeared for now. I haven't heard it all day. It was a bit warmer outside today so maybe that has something to do with it. I'll keep my eye (or ear) on it.