My 190e 2.6 89 MB overheats when the car is not moving. The temperature drops when the car moves, but I know it is nor a normal operation.

I suspect that the clutch is not tuning the fan faster when the temperature increases. Is there a way to test the clutch or is there a sensor that turns up the speed of the fan and how can I test it?

Any other recommendations?

benzoso

Mine started doing that just before a scheduled coolant change. While I was there I changed the plastic thermostat housing with a metal one. While I was there I changed the thermostat. WHen I saw the old thermostat I found out why it was overheating when it wan not moving: the thermostat had physically broken, I'm lucky the water pump didn't start chewing on the parts


IMHO thermostats should be regularly changed every 5 years or so. How old is yours?

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5 speed '91 190E 2.6 320,000 mi. (new car, fast, smooth as silk six, couldn't find any more Peugeots)
5 speed '85 Peugeot 505 2.5l Turbo Diesel 266,000 mi. (old car, fast for a diesel, had 2 others)
5 speed '01 Jetta V6 (new wifes car, pretty quick)
5 speed '85 Peugeot 505 2.2l Turbo Gas 197,000 mi. (wifes car, faster, sadly gone just short of 200k )
5 speed '83 Yamaha 750 Maxim 14,000 mi. (fastest)
0 speed 4' x 8' 1800 lb Harbor Freight utility trailer (only as fast as what's pulling it)

I had the same problem with my 190E 2.6. It turned out to be the thermostat. The thermostat would open only a crack and would cause poor circulation at low speeds but the temp would be normal on the highway. It is very easy to check the thermostat on these cars about 5 minutes. I would recommend replacing it as the first thing you do. It cost about $25.

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1990 190E 2.6
1996 Grand Voyager 3.3
1985 Mustang GT 5.0 5 SPD
1982 Suzuki GS 750T

My thermostat only cost me less than $11.00 here at Partsshop/Fastlane.

__________________
2006 E350 w/ 155k miles (Daily Driver)

Previous:
1993 300E 3.2L Sedan w/ close to about 300k miles
2003 E500 Brilliant Silver (Had 217k miles when totalled!)
1989 300E with 289,000 miles (had for <1 yr while in HI)
03 CLK 500 cabrio (Mom's)
2006 C230k (Dad's)
1999 S420 (Mom's/Dad's)
2000 C230k Sport sedans
2001 CLK320 Cabrio (Mom's)
1995 C280 My First Mercedes-Benz... (155k miles. EXCEPTIONAL AUTOMOBILE. Was Very hard to let go of!)

Benzoso

Unfortunatly once a viscous fan has had its day its a replacement one im afraid. The actual viscous has probably dried up and isnt operating the clutch anymore. There are a couple of things you can do.

1) replace the thermostat, this is always good practise and they are only a few £/$ or whatever to buy.
2) Get a replacement fan
3) Scrap the viscous fan altogether and fit an electric one, they are much more efficient, and dont drain valuable engine BHP when they are running.

The fan you have got is easy enough to test. The fan should come on about 100 degress on your temp gauge. at about 100 degrees, rev the engine, you will be able to hear a rush of air as the fan spins round with the speed of the engine rather than freewheeling as it normally would be. Let the temp creep to about 105-110, if by then the fan hasnt kicked in, then thats your problem, and a replacement is needed. I would never let the temp go over 110 if you can help it.

I note you say that on crusing the temp is fine, so i reckon its the fan thats at fault.

cheers