I have recently developed what sounds to be a grinding pulley noise on my 87 420sel, just broke 100000 miles. I have had the valve covers off and replaced those seals a 100 miles or so ago. At that time the timing chain guides looked OK, not sure if they were replaced but looked OK. The "grinding noise" I hear sounds to come from a pulley not internal. I am having trouble isolating it. The car starts and runs fine but the sound is constant. AC unit, failing water pump, fan clutch? Any help would be cool...
JD

You would have a better shot at securing a reply by posting this question in the Tech Help section of this website.

Maybe so but they wouldn't get the smart arsed remarks and political disagreements they can get on this forum!

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I'm pretty sure that Obama's birth in Kenya wouldn't cause a grinding sound in a M116 engine.

Pulling the accessory belts one at a time may isolate the item for you. Or if serpentine belted let you hand check each one. Could be as simple as the tensioner pulley.
]Care with a device used as a sound locator might also help before removing belt or belts.

When I run into something like this I use a cheap Stethoscope and a wooded dowel rod.

Just place the end of the dowel on the end of the stethoscope and then use it as a probe to see just where the noise is coming from. If somehow the dowel gets tangled in the fan or a belt then just let go of it and use another one.

You can buy these made up for automotive use, but if the probe gets into the fan it will rip the thing off your head.

This really will pin down the noise, though. You can hear an individual hyd lifter in an American V-8 with one.