Overheating C280 mystery

[xychrmsme]

Have a 1995 C280 with 80k on it, just bought the car a month ago. I bought the car on a cool day, no problems noted. Next day was warm and the car was running hot. Took it to the mechanic and had thermostat changed, along with wire harness and other parts. Mechanic stated he could not get the car to run hot -was a cool day again.

Today driving with the AC, hot day, car temp creeps up towards 120, misfires, suspension making horrible noises.

The radiator and fan clutch are fine, but the aux fans only come on for 10 seconds. I thought they were supposed to come on as soon as the AC was turned on, mechanic says only periodically.

I like this car but did not expect to have so much shop time so far, and expense on a one owner Mercedes dealer maintained vehicle.

Thanks in advance

Cory

[Gunawan]

Dear xychrmsme,
I'm not expert, but I suspect several things.
1. The thermoswitch on the engine is not working properly.
2. The extra fan's resistor not working because usually corroded.
3. The thermostat is installed backward, so the coolant flow is not normal.
These are things that can make engine overheating. Living in the Tropics, overheating is one common problem for me.
Hope you find the problem.
Bye

[xychrmsme]

Wondering if the aux fans should come on when the air conditioning is turned on in w202 cars. Anyone?

[suginami]

Yes, generally speaking, the low speed fan should come on when the a/c is on.

If it doesn't, check the fuse.

Further, the high speed fan is supposed to engage at 107, and stay on until the car cools down to 100.

[Gilly]

Make sure the engine fan blade is installed into the clutch the right way. They can be installed backwards, very hard to tell. Often times it will be up to a bodyshop tech to do this work, and not meaning to slam a bodyshop tech, BUT they have been known to get it wrong, lets leave it at that.

Gilly