I have a 1998 E300 diesel with 230K miles. When the engine is first started there is small squeeling sound every 1 second. As the engine warms (ie a couple of minutes), the sound gets louder. I believe it is the fan clutch. I have replaced the water pump and the central idler pulley within the last year so it is probably not those components.

When I turn the fan, it turns smoothly but stops turning as soon as I stop turning it. I am looking for the best way to touble shoot this. Any ideas?


Thanks