Squeakt heating ducts

[Gary]

There is a loud squeak coming from the vents. It squeaks like a bad belt. It starts in the middle vents and then may shift to the driver vent. It then disappears, only to return an hour later. Once I turn the heater off it stops. Same sound when on econ mode. Could it be a motor going bad?

[Robert Goodwin]

Gary,

Is the problem with one of the 2 cars you list? If so, which one? The systems are completely different in those cars.

[Gary]

The 124 body- 300D

[Robert Goodwin]

Is the squeak speed dependent? Does it change when you change the blower speed control with the push buttons on the climate control unit? If so, I would suspect the blower unit. See the wiper motor post by ratcliff on 9-20-2004 at:
http://mbca.cartama.net/showthread.php?s=&threadid=3761
Get a pair of new dust filters before starting. You don't want to have to go back later to replace them. Use the procedure in the above link to remove the wiper motor. That will put you at the filters and top cover of the box containing the fan. A few clips hold the cover in place. Run the fan with the cover removed and confirm that that is the problem. Whether it is or not, put a few drops of ATF on either end of the squirrel cage bearings. Reinstall everything, servicing the wiper assembly on the way. You will have performed 3 seperate maintenance procedures when you are ffinished. If you are hesitant about lubing the wiper assembly, you should know that it is not an MB service procedure. They replace it and the resultant burned out motor for about$1,000. Let us know if this procedure works for you.

[Gary]

Thanks

[Jim Schaffner]

I have an 1987 300D turbo. The squeaking was driving me batty. I didn't notice it on high speed, but on automatic...it was nerve-racking.

I took it apart and put some oil on the blower bearings. Problem solved!

I would allow about 3 hours for the job.

You may want to purchase some lower windshield trim clips before you start. Mine were a bit rusty and broke when removing the trim. Six new clips and some stainless steel pop rivits will do fine.

Go Luck..

Jim Schaffner

[rwmastel]

I recently had the same problem on my 1994 E420. Replaced under Starmark.