300E Running Hot?
I recently bought my first Mercedes, an '86 300E with 93,000 miles on it. I'm trying to get it ready to take the family on vacation in August from L.A. to Washington/Canada. Driving in So. Calif., the AC is on quite often and it seems to run a bit hot. I'm assuming the line on the temp gauge between 80 and 120 is 100 C, and when I'm stuck in traffic or driving at low speeds through town the needle sometimes gets up almost halfway between 100 and 120. Is this too hot? With the AC off, the temp stays usually around 80 - 85. With the AC on, the electric fan comes on at some point, but doesn't seem to be pushing a lot of air. Will these fans slow down with age or use? Any easy way to test if it's running up to speed? Also, what's the best way to test the viscous fan clutch to make sure it's working as efficiently as possible.
I plan on replacing the original radiator before the neck snaps off, and the PO said the thermostat was replaced about 2 mos. ago, but I'll probably check it while I'm in there. What's the proper temp for hot weather use?
The water pump looks like it was maybe replaced, as there is silicone seal squeezed out of the joint, so I'm assuming it's probably good (no obvious leaks).
Where is the thermo switch that kicks on the fan? Can I test it with an ohmeter in hot water? What temp should trigger it?
Thanks for any help