1990 Pioneer, STILL OVERHEATING! PLEASE HELP!

Hello all, I posted a thread a couple days ago ( I think the original thread is on the second page in this forum) in regards to my 1990 Pioneer and its overheating problems, I installed a new coolant reservoir, a volvo cap, new thermostat/ thermostat housing etc.... I took it towards the mountains this evening to test it out, on the way there I was in 30 minutes of rush hour bumper to bumper traffic and it ran at 210 the whole time. As soon as I got on the highway it started to heat up. I was driving about 65-70 mph. The temp gauge started to get near the red, I stopped and let it cool down. I headed back home at that point, it started to get back near the red on the temp gauge again, I stopped again and let it cool down. As soon as I got back into the city and driving 30 mph again it ran right at 210 for at least 30 minutes until I got home. It appears that it only wants to overheat when Im driving at high way speeds and on a small incline. Any help or ideas would be greatly appreciated! Thanks again.

If I recall from your earlier thread, you pretty much replaced all the easy stuff. I would start to suspect the water pump at this point. Are you losing any coolant, like a dribble from the water pump pulley shaft?

How old is the FanClutch? Is it easy to turn or hard when it is hot.With the motor OFF after you have been driving it for awhile check to see if the fan is easy or hard.MAKE SURE THE MOTOR IS OFF when you check.Watch it cause it well be hot

I am not leaking from the weap hole or any where else from the water pump and it is not making any loud bearing noise just yet either. Im not sure how old the fan clutch is. There is some resistance when I turn the fan clutch when the engine is hot.

1990Pioneer said:

I am not leaking from the weap hole or any where else from the water pump and it is not making any loud bearing noise just yet either. Im not sure how old the fan clutch is. There is some resistance when I turn the fan clutch when the engine is hot.

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At highway sppeds the fan clutch is not a big issue. It's there for low speeds. The water pump impellers could be corroded off or your radiator partially plugged. If yo uhave a radiator with metal tanks, take it to a local radiator shop and see if they can rod it out for you.