I am an admitted newbie to these forums and to a recently purchased 1990 190E, 2.6. So far this forum has been a huge help, but now I am lost & confused in a multiude of postings regarding cooling problems. I have done several searches for this info before posting and bothering anybody, but the replys are numerous and seem to mix information between models/engines.

To make it simple, what is controling the main radiator fan (magnetic?) on my 2.6?

Is it indeed an electromagnetic fan clutch on this model or is it only electromagnetic on the 2.3?

Is it the 3 pin engine coolant sensor located toward the rear of the block closest to the firewall that engaes the clutch?

The two electric aux fans are controlled by the aux fan sensor (front of block) and the aux fan resistor, is this correct?

Is there also a fan relay (orange/40 amp protected) on the top of the fuse box in the 2.6? Is this relay used in the electric aux fan circuit or the magnetic clutch fan circuit?

These simple answers will sort out my confusion and get me on my way.

Thanks,

Perry

The mechanically driven fan on the 190E 2.6 is a thermo-viscous drive. It keys off radiator exit air temperature, but the clutch typically tightens at about 100C coolant temp (as displayed on your IP gage), and at this point you will probably hear "fan roar" at 2000 revs.

The early 2.3s have an electromechanical clutch that actuates the mechanical fan. I'm not sure if later 2.3s are the same or viscous.

The electric fans on your car should engage at high speed at about 105C coolant temp, and when the A/C is on they will engage at low speed periodically in low speed driving based on A/C cooling demand.

I recently posted a way to test all the fan functions.

Duke

That sorts it out for me. Thanks for the help!

Perry

While trying to purchase a replacement, Fast Lane and some other sites show two different P/N's for this 1990, 190E 2.6 visco clutch depending on engine series.

********, whom I've been using for parts in the past, only shows one part number (better price). I would like to buy from them unless unadvisable for some reason.

Also, Fast Lane is advising that three OEM nuts are needed for install if engine is within specific range.

Any guidance out there?