engine whine in 91 300E
 

Hey folks,
Just got my 1991 300E 24V back from my mechanic with a new head gasket.

It idles a little slowly but more worrisome to me is a fairly loud whine that gets louder and higher with increasing revs. Any ideas what could cause the whining?

Don't drive the car OR run the engine!!!

Most likely the chain tensioner hasn't been installed properly!

Have the valve cover removed & the chain checked for excessive tightness.

When installing the tensioner it must be "RESET" & installed disassembled.

You were right on the money. Thanks so much.

Stirling, your mechanic should have realized something was wrong before returning the car to you. He needs remedial training on timing chain tensioners. Hopefully the installation of the head gasket and resealing of the upper timing chain cover were done correctly and oil leaks don't develop soon. I recommend you find another tech for future repair work. Fortunately you sensed something was wrong and M.B.DOC's advice prevented a major problem this time.