I have a 1981 300D with 196k. the car runs great. But as the weather is getting warmer I noticed that my engine temp is going up. This is normal. However at idle or in heavy traffic it is running much hotter than normal. Last fall I was told the fan clutch is bad. How can i verify this? I am thinking this could be the problem since the engine only gets hot at low speeds or idle. Also at what temp should the electric fan turn on? I replaced all the hoses and coolant last year as preventive maintenance and notice that it seemed to have good water flow thru the radiator. Can a bad water pump cause this? Any help is appreciated.

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Mark B

81 300D

No matter what, replace the thermostat and the cap first. If problems persist, then look elsewhere. When very hot and in neutral with the engine at 2000 or so, you should be able to here it come in and out...

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Benzmac:
Donnie Drummonds
1981 280GE SWB
1987 16V
ASE CERTIFIED MASTER AUTO TECHNICIAN
SERVICE MANAGER FOR 14 BAY FACILITY
MERCEDES SPECIALIST 8 YRS
PARTNER IN MERCEDESSHOP.COM