Hey everyone,

1982 244 B21 2.1L KJet 132k miles

Car has been running great after all the work I've put in over the last year, but over the last six weeks or so I have started hearing this high pitched whine, almost like a whistle. I can only hear it when the car is idling, and it seems to come and go, it isn't constant. Also seems to be a bit louder when the ambient temp is hotter. The pitch frequency doesn't change with throttle inputs, it only goes away when I rev the motor and then returns when settled back into idle. When I shift into a drive gear, the sound disappears completely. At speed on the road I cannot detect anything. I have never heard the sound other than being in park or neutral at idle.

After searching underneath the car and in the engine bay for some time, it seems to be coming from the top front of the motor, in the area of either the camshaft or possibly intermediate shaft. I first replaced the timing belt tensioner, belt (since I was there) and water pump, thinking it was one of those, and while the sound seems to have diminished in volume, it's still there.

I have not been able to find anything resembling these symptoms while scouring the boards. My thoughts now are possibly intermediate shaft bearings or camshaft bearings? I have never opened up one of these motors, or any motor for that matter, so my experience in diagnosing internal engine sounds is limited.

Here is a link to a video I made just the other day that highlights the issue quite well. I have since installed the new timing belt tensioner and water pump so it's not quite as loud as the video, but still quite noticeable:

https://www.youtube.com/watch?v=lGZkMkkzH_k

Thank you all in advance for your suggestions and advice!