1987 190E 2.6 running hot
 

How do you find out if the heat problem comes from the headgasket going bad. Nothing drips and slowly the temp rises to the max 120 area.
the car has 115k miles
Thanks.

smells like an aux fan gone bad..

i don't think you are anywhere near a head gasket in a 103

aux fan ===about $100 diy

I didn't give enough info but both fans came on as the temp rose.
Thanks for your reply

Why not change the thermostat? Are you loosing coolant from the tank?

thermostat, next..

20 dollars.... it's either that or your radiator is clogged....not likely.

Thanks for your replys
I removed the thermostat and drove the car this evening for 1/2 hour, the temp stayed low at just below 80 deg. when I parked back on the driveway the temp started climbing up and the aux fans started running. The radiator was supposedly replaced 2 years ago.
Could it be the fan clutch acting up?

How old is the water pump? If it has been in there a while and or with green coolant the fins can corrode. Might not move enough coolant at low RPM's to keep it cool.

The water pump could be the original but I'm not sure. The coolant is green and the previous owner had it serviced a a indi mercedes shop.
How do you know if the belt driven fan is doing it's job?
Is there a way to test it with a timing light? compare it to the water pump pulley and see if it is going at the same RPM? What RPM should it be turning at in comparison? Any ideas?

If the belt driven fan (fan clutch) does not work and the aux fan does, the temp will never get past 115 degrees.

You can test it by running until above 110 and then shutting off the engine. Pop the hood and try to spin the fan by hand. If it turns easily it has failed.

I run the car until it reached about 90 deg then I shut off the motor and watched the fan spin about 5 full truns before it came to a stop.
I was able to spin it very easily 5 or 6 turns. I read that may be an indication that the fluid is gone. I will try to refill and see if it makes a difference.

Replaced the fan clutch, and car was still running hot, tested the thermostat in boiling water and it did not opne at all. Replaced it and now the temp is perfect, New fan and thermostat did the trick. Thanks guys for your info.

Don't drive it without the thermostat in place, it will overheat.

Replace the fan clutch, flush and replace the coolant with MB of Zerex G-05 ONLY -- the green stuff will eat the head, sure as the sun comes up, even if changed often.

While you have the coolant out, pull the radiator and clean all the squashed bugs and road crud of it, they fill up pretty fast if you live in an area with lots of flying insects in the summer.

Oh, and replace the radiator cap while you're at it.

Peter

Now I need to remove the crappy coolant and replace with the correct stuff. Thanks.
Wife likes the car, and I am very happy today. :cool:
If I only figure out why the emmissions are too high to pass the smog test.