idler pulley vibration 90 350 SDL
 

Well the old "rod bender" passed 250K, only problem is idler pulley vibration. I have replaced every thing that can be replaced and it still vibrates. Anyone now of a solution? Not a big problem but really noisy when cold.

Did you replace the tensioner shock?

when i said i replaced everything that could be replaced that's what i meant.

Mine vibrates a bit when the ac is running. Do you have the correct length belt? Benz specifies a different one for the 3.0, the 2.5, and the 3.5 for some reason. Don't know what the difference is, I'm using the one AutoZone spec'd, same as a Buick 3800.

-J

Does the idler feel loose and/or make noise when spun with the belt off? Is the idler bracket solidly attached to the head?

Sixto
87 300D

Look closely at all the pulley grooves,on my 91 rubber & dirt had built up in the grooves and was causing the tensioner to vibrate,cleaning them cured the problem. Not hard to do but it does take some time to do them all. Don