bottedi

Quick question: In my 2002 ML320, I just started having a weird new problem. Every morning when I start the car, I hear a very high pitched noise coming from the dash area. It sounds like a pizo buzzer going crazy! Very high pitched and very loud. It lasts for about 1 - 2 minutes and then just stops. I tried to switch all of the various systems in the car on and off, but there does not seem to be a correlation.

Any help would be appreciated.

Thanks

sosh

Likely that its the E Box fan starting to fail. Not a big deal but should be corrected as soon as possible to avoid damage to the electronics from overheat.

marcelc

Go to http://www.keysolutions.com/M-Class.nsf/Home? and search for Dirty E-Box Fan submitted by Ken Yee for the process.

My e-box fan was screeching when it started on cold days so I followed the above procedure, cleaned away the dust from the brushes, oiled the bearings and replaced it all in well under half an hour and it is now as quiet as it should be although it is not cold here at the moment.

If you wish to replace it, be sure you buy the Brushless Papst replacement, according to Wolfgang, Pabst's RV40-18/12L is the replacement one (not the one with an H suffix):
http://www.ebmpapst.com/index/sid/3A...0-141568634CC1

YuCrew

I've checked with the technical folks at ebm-Papst and they say that neither the H nor the L is the correct part. The Merdedes application is somewhere in between the High and the Low performance parts and they further say the part for Mercedes has additional moisture protection. Upon further analysis and comparison of the Bosch and the ebm-Papst fan curves, I believe their statement about the performance difference is accurate. However, one could argue the L is better than NO fan running. And from the looks of the Bosch item, it's pretty clean and protected in the fusebox itself. While the RV40-18/12L and 18/12H are both readily available at around $50, they do not have the plug so you will have to use your old one.

The ebm-Papst part number on the exact Mercedes replacement part is RV40-18/12GU-015.

For $60.49, free shipping, I bought this exact part (MB#129 545 00 95). Send me a private message and I will tell you where I found this low price.

AndrewAZ

When my 2002 ml made a noise like that it turned out to be the aspirator motor. So if the Ebox fan is not the cause then check out the aspirator motor.

bottedi

Thanks for the tips, but I don't know what the E box, and more importantly, where the E box is. Same thing goes for the aspirator motor.

Can someone give me a "directions for dummies"?
Thanks!

My Self

It's a fairly simple DIY job.
I'll assume you clicked on the links above.
If that doesn't ring a bell with you, and you still need "directions for dummies", maybe you would be better served by letting professionals do it.