W124: Diagnose a Vague Sound! - PeachParts Mercedes-Benz Forum

EliotW · #1 07-19-2007, 02:32 AM

Just looking for off the top of your head suggestions. I've yet to take anything apart.

A hrrrrrrr sound. Constant without change in pitch or tone after the first h. Intermittent, it might occur twice in the 30 minute drive with each episode lasting at least three seconds and as long as eight. It appears to come from the front left of the car but that could be entirely misleading. Occurs regardless of temperature or precipitation.

The car is an E420 with 145,000 miles. The rear subframe came out last year for a job and all the rubber bits (along with the multilink) were replaced. That is not true of the front.

spit64 · #2 07-19-2007, 02:56 AM

could be the chain tensioner or belt tensioner.

EliotW · #3 07-19-2007, 04:45 AM

That sounds plausible... its a bit of squealing sound that catches itself in at the very beginning and then becomes quite even.

juribe2 · #4 07-19-2007, 09:12 AM

When was the last time you replaced the motor mounts? That sounds like the fan blades making contact with the shroud. Do you feel any vibrations? Is the car running well?

Check those motor mounts. I hope this helps.

david s poole · #5 07-19-2007, 10:06 AM

open the hood and get flashlight and look at the clearance btwn fan blades and shroud.chances are there is a lot at the top and you can't see the bottom.this usually means that the motor mounts have collapsed and the engine is too low in compartment.as stated earlier replace mounts.

EliotW · #6 07-19-2007, 07:43 PM

There was excess of inch, inch and a quarter space between the top of the shroud and the blades. At the bottom it was quite close with what looked like a light abrasion. There was also some nicking on the blades.

Thanks