I did search here for noise, stayed running, fan sound, whirring, buzzing and several variations. The closest thread talked about the emissions air pump but none of the posts talked about it running after the car is turned off.

After about a 3 mile drive home after I got out of the car I heard a fan type sound up front. I didn't think too much of it knowing the car has an electric fan and it may stay on with the car turned off. Two hours later I walked out by the car and it's still making the noise. Popped the hood and the fan wasn't turning. The noise was loudest at the top front of the engine just under the cover.

Any ideas what it might be?

I started the car then shut it back off and the noise is gone.

 

I had a dremmel sounding whirl come from the top/front of my engine. Never knew what it was.

 

My guess is the air pump contacts stuck in the RCM. But why it would continue with the ignition off is puzzling, but if the RCM is always live I guess that would answer it.

 

Thanks guys. It hasn't stuck since so we'll see how it goes the next few times out.

 

I think you nailed it. I didn't have the stuck on problem again however a few weeks later I got a P0140 code. I searched the boards & found the RCM issues and the poor ground issue right at the pump. Pulled the RCM and cleaned the contacts, re-soldered some suspect connections then cleaned the ground at the pump. All is OK so far! I suspect the sticking contact then became corroded or arc burned preventing the pump from coming on thus the engine code. It's really all a guess at this point but so far no light back on. Thank You to all who have posted pics & how to's!