Today I was stuck in traffic which isn't typically. Sitting there with the radio and ac off I noticed a high pitched hum masking the sound of my engine. This was most noticeable when idling @ 750. While sitting there the rpms would slowly increase to 800 at which point the hum went away and I could hear the engine clearly. 2 seconds later it would drop back to 750 and the hum would return. When I give it the slightest amount of gas the hum goes away and is never noticeable when the car is moving. This was before it was fully warmed up. When the traffic cleared I made it to work and then sat in my parking space. The hum was still there but less noticeable. Is this normal? Any thoughts?

 

I had a similar issue and just completed repair. Dealer said it was a solenoid and hose replacement issue. You can see my post here:

https://www.6speedonline.com/forums/...ose-video.html

 

Sounds like that might be it. Actually haven't had a chance to listen to it from outside the car. Will do so tonight and see if it matches yours. The frequency of the tone sounds the same so I think it's a match. Do you remember how much the repair was? Is this an urgent repair? Thanks a lot. Really appreciate the info

 

if its higher pitched it could be a belt driven bad bearing. I had a water pump bearing go out on me.

After a certain RPM it would drown out, but at idle it was easy to hear from inside car. From outside car, even with ear in the engine bay it was hard to pinpoint.

took my dealer 4 weeks to identify and fix, fun times.

 

If it is a 2009 car then it could be the water pump. A dealer can diagnose this very easily and it is an easy fix.

 

As far as I know, it wasn't a urgent repair and note the noise would only be evident after spirited driving. My car is under warranty so I don't know exactly the cost, but the advisor told me it was a couple of hours to repair not including diagnosis.