190 E COOLING PROBLEMS HELP/ADVICE PLEASE

[TJC46]

Hi guys newbie on here just visiting from the TVR chiamera forum. Problem is my fathers 1992 190 E automatic is giving him a few overheating problems. The car has always been fine on the move but the temp did tend to creep up when stationary i.e. in heavy traffic. Just lately its been going very hot in traffic, so im wondering how the fan on this model works. It seems to be totally free spinning and not driven in anyway by the water pump, is this right? I do have a good mechanical knowledge[i own a TVR chiamera so you have too] and most cooling systems operate at there optimum with the car on the move with cold air forced thru the radiator and when stationary in traffic via a temp probe which when it has reached a certain temp, operates a switch to turn on the electric fan, but with this fan totally free spinning, how is the radiator cooled, The system has been totally flushed and checked for leaks, and the thermostat has also been removed, its fine when on the move but wants to overheat when stationary. Any one please help/ideas, especially concerning the "FREESPINNING FAN" thanks Tom.

[Pentoman]

Bit late but... the fan is free spinning until you hit about 107 degrees, maybe 108 on the gauge. Then the fan switch, a simple metal thermostat, is activated and closes a connection to start the fan spinning. The fan isn't electric it is clutched to the engine. When the fan cuts in and activates you can feel the high loss of engine power if you accelerate up the rev range, and you can hear the loud sound too. I panic in my 190 when in traffic as the gauge goes uncomfortably high but the temp always comes down once the fan kicks in.

Nice simple system. Better get a new (from Mercedes - my dodgy aftermarket one from GSF did not work and the fan was always on..) one, not expensive and 2 minutes to change with engine cool.

You can even test the fan by shorting the connector that goes on to the fan switch. Keep hands clear of fan!

[derin100]

As above ^^^

I had exactly this problem on my 190E and found this thread and the chaps here to be very helpful:

http://s14.zetaboards.com/mercedes_190_club/topic/...

Nearer the end of the thread you'll see links/photos of the sensor switch which is likely to be the culprit. If you bridge across the terminals on the connector to it you should here the electromagnets for the fan "Click".

[TJC46]

Thanks guys put a link in on the 2no wires and the fan worked perfectly, in this case its magnetic , when the critical temp is reached the thermo switch closes the loop and you hear and can actually see the once free spinning fan magnetically pull towards the water pump pulley, one new thermo switch later[genuine merc for £14] all works perfectly.

[Pentoman]

I have to credit my Dad with the tip about shorting the connector to test the fan, first showed me that way back in 2002 or something. Lifelong mechanic, must have some good knowledge up there in his brain.

190s are so damn solid.