I have been reading through the numerous overheating threads trying to track my problem down. Its been a learning experience between my various service manuals, yotatech, and mechanic's opinions, but I wanted to post on here my experience, symptoms, and solutions to help anyone else out.

Its an 84 4runner 22r with a Weber 36/38(not sure) carb, headers, some type of cam, and custom exhaust. This is the truck I purchased back after 10 years so I am not 100% on what mods have been done. The engine is from ATK and has about 25K on it.

When I went to Minneapolis to pick it up, it overheated while driving around in the city..not in the red, but it would move past the midpoint and keep moving unless I turned on the heat and pulled over. I ended up taking it to a service station and let them test it out. They were not sure either, but they did flush it and change the t-stat. All seemed good for a day until we got on the road and started heading back to TX. It would move past the middle whenever I would cruise at 2500 rpms or higher or if we encounterd large long hills or short steep ones(Arkansas scenic highway). If we came in off the highway, it would get hot too, but it never got into the red.

Back in Austin, I started switching stuff out. I put a new thermostat in, drilled a hole in it, bought a 3 row radiator, new hoses, a toyota two stage t-stat, and switched over to Toyota red. It would still overheat.
Now, I "checked the fan clutch" but I guess my idea of feeling resistance on the fan when it was hot was not correct. My mechanic immediately showed me my error and said that was the problem! I bought a new fan clutch, and put it in last night, and so far, so good...but I am crossing my fingers that it did the trick.

I just wanted to post my symptoms and solutions for anyone else that is going through the same crap.

 

Glad you got your problem fixed!

I'm still diagnosing mine. I've got a thread going too. General consensuses seems to be my radiator is clogged. New one arrived yesterday. Gonna put it in tonight.... I hope to get it all figured out.

 

its been a few days, and my truck has not gone past the mid point on the gauge. Its very hot in Austin right now, so I am going to say that the fan clutch was the problem...I hope!

 

You should know whether your fan is working correctly or not. Your trucks sound like a tractor when the fan starts to operate as oppossed to idleing.