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