Help!

From new we have had a whine at around 1400 rpm ,1500rpm, and tapering off by 2000 rpm. It is most noticeable in low gears. But on a smooth street at a steady 49 mph it can also be heard. It is also detectable in park when revving the motor.

Probing with a stethoscope it sounds like it is commuting from the straight cut gears that link the cams.

I have learned that the exhaust cam drive gears have a sandwiched spring loaded section that is intended to reduce noise.

The dealer compared my car to one of there fleet 2011's and it had the same whine. There conclusion being that they both made the same noise and thus it is normal.

Any one know of a fix? Thanks!

There's been a fair amount of bad press concerning the M272 engine

Mercedes-Benz M272 engine - Wikipedia, the free encyclopedia

Mercedes-Benz S-Class W221 2006 - Car Review | Honest John

Most of the trouble seems to be balance shaft related. Could that be the trouble you are experiencing?

__________________
1992 W201 190E 1.8 171,000 km - Daily driver
1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone
1965 Land Rover Series 2a Station Wagon CIS recovery therapy!
1961 Volvo PV544 Bare metal rat rod-ish thing

I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior



Don't leave that there - I'll take it to bits!

Thank you for the input. Read about the balance shaft and that seems to be cleaned up before 2011.

Did put the stethoscope at the balance shaft and oil pump locations but the noise seems concentrated at the front of the cams.