Unofficialbmw.com

[sphudson]

Hello Everyone,

I've got a 1999 323i with about 45,500 miles. Whenever I press the gas pedal, a slight, but brief, humming noise is heard from the engine compartment. I also hear this whenever I turn off the engine.

The hum is brief (<1 second). The sound appears to be coming from the top part of the engine.

Any ideas? (could it be the timing belt?).

Thanks in advance,
Stanford Hudson
USA

[zoidJoker]

I also have a 1999 323i and encountering the same problem with a humming noise coming from the engine when I turn the engine off or give it some gas. I recently changed my belts but with no luck the humming is still there. I believe that the heat plate under the exhauster near my headers creates the noise. I have inspected the heat plate and have found that it is lose on one of the corners. I have not had a chance to fix it but when I do I will keep you posted if it fixes the problem.

P.S Be aware that you should change your belts every 70,000Km or so, if not you will get loud scretching sounds on hard accelerations

[rld777]

Hello,

Not too sure about this, but is there a chance that sound is a fuel pump or lift pump? I recall that on many late-model Chevrolet trucks, the fuel pump is rather noisy, and will run for a few seconds ater engine shutdown to prepare the system for the next start-up. Haven't noticed this on my current E-36, perhaps it's different on the E-46. Just a thought...