The sound came after an hour of freeway driving. It matched the engine speed and sounded like either thin metal or plastic hitting something. I pulled over and the sound became more metallic and high pitched. The engine died when it came to an idle.

I can start the engine and it will run with throttle, making these occasional high pitched, sharp noises. But it dies at idle. There was no blue smoke and no more than usual black smoke. I removed the air cleaner and ran it listening if the noise came from the turbo, but it didn't. I removed the valve cover and watched it run. The valves seemed OK. The sound seems to be coming from within the engine.

Now, I had just run the car up to 105mph a few miles earlier. It still had plenty left when I backed off the throttle and the sound didn't come up at that time.

I know one can't troubleshoot a car over the net but I'm open to ideas and at a bit of a loss as to how to proceed from here.

1984 300SD
188k miles



Thanks in advance!



randy