Hello Peaches!

I just replaced my fan clutch for a few reasons:
1. It is hot in Texas again!
2. The engine fan would keep spinning for several seconds after I would switch off the engine.
3. Car would hit 100C, then the aux fans would come on. (sitting in traffic on the highway)
4. In my time with the 300E, I have never heard the fan "roar", it spins, but I just think it has been worn out since I had the car. I have read quite a few threads about the fan clutch, and many people mention that you should be hearing a distinct roar from the fan when the engine is at operating temp.

The fan clutch I removed from my car was a Behr unit, but it appears that it was tampered with. The bi-metallic strip was bent near the middle, and appears to have a dime or some metal disc wedged in it.

So I replaced the fan clutch this morning using the instructions from the factory service manual sheets.

After I buttoned everything up, I started up the car and checked to make sure everything I touched was still spinning true and that no odd grinding noises were coming from the fan clutch or surrounding area.

I left the car to idle for about 3 minutes in the driveway. Then I took her out for a spin around the block. The first thing I noticed is that I can finally hear the fan roar when accelerating. (AWESOME!)

After about 10 minutes of driving in this warm afternoon weather, stopping and accelerating around the neighborhood, the temp gauge never once crossed the 80C mark. (AWESOME!)

Then I remembered a thread on this forum about how Behr viscous fan clutch units are really bad and are generic designs used in tractors and heavy truck engines and are always engaged, even at high RPMS.

To test this, when I was stopped I shifted the transmission to hold 1st gear and accelerated slowly, raising the RPMs to about 4000.
THE NOISE FROM THE FAN WAS REALLY REALLY LOUD. (NOT GOOD)

So my guess it that the Behr fan clutch really is not good to use with our Mercedes-Benz cars. Peach Parts sells two brands, a Behr unit and an ACM unit. Another vender sells a Behr unit and a Fichtel-Sachs unit.

Should I try the ACM, Fichtel-Sachs or bite the bullet and get one from the dealer?


Above: Tampered Behr fan clutch pulled from car. (Old unit)

__________________
2006 BMW M5 "Heidi" @ 109,000 miles
2005 MBZ C55 AMG "Lorelai" @ 165,000 miles
1991 MBZ 300E "Benzachino II" @ 165,000 miles
1990 MBZ 500SL "Shoshanna" @ 118,000 miles

(On the hunt for a good used M103 engine as of 6/10/23, PM me if you have one to sell!)