1983 300D Turbodiesel - Automatic - ~220,000 miles

Today, while the engine was running at idle and the car was parked, a loud shrieking noise was heard from somewhere in the left (USA drivers side) rear of the car. It almost sounded like it was IN the trunk.

It's my understanding that there is just one fuel pump, and it's on the engine itself.

I've heard this 2-3 other times, lasting just a few seconds, over the last 2 years. Today was the loudest and longest lasting, at about 15 seconds perhaps. It immediately stopped when I had moved the car...

Any ideas would be most appreciated. I'm trying to get this car tip-top. :-D



BTW - I suspect that my motor mounts are totally gone and perhaps this noise, erratically varying in pitch, may be a weird vibration being transmitted through the drive shaft or even car body, and is causing the noise in the rear left wheel or suspension??? Just my guess but perhaps this has been seen, or at least heard, before. ;-)