i have a 1978 toyota 4x4 pick up. i have an overheating problem and i have lost power, the truck never gets how when i idle but driving down the road it gets hot i have changed the themostat and the coolant any info? i also have a power problem driving down the road it just cut out on me i had the gas all the way doen and never got over 30mph any info would help thx!!!!

 

Is it a 20R or a 22? You may have a head or head gasket problem. I had an 84 doin somethin similar once til finally it just cooked itself.

 

Yeah, check your compression, and make sure there's no coolant in the oil or oil in the coolant.

 

its a 20r.

 

How hot has it gotten? It doesn't take much heat to mess them up but I have a feeling that something with the head is already messed up and that's what is causing the problem. When did it start doing this and did you do anything to the truck around the same time? A lean running engine will produce more heat say if you had done some carb tuning.

 

ok yeah i did some work on the carb and it was after that!

 

Yeah it may be running a little lean. Pull your spark plugs out and see what color they are.

 

If it gets hot driving down the road, then that is a sure sign your fan clutch is going out...

 

Could be that too its just weird that it doesn't get hot idling

 

You should probably check your ignition timing too

 

Any updates?

 

yeah i started with checking oil it was clean, then went to the fan it seems to be working fine but kinda hard for me to tell! the timing is off but i still need to get into it and i made some adjustments on the carb but didnt help!

 

Id get the timing straight and hopefully that'll take care of it. The clutch could be bad on the fan but I don't know a good way to test it. Maybe someone else will chime in

 

I don't know how to test it, either...some people stick their hand in there while it's running, and if you can stop it with your hand, it's going bad...but I decided against trying that. Someone told me to try turning it by hand right after shutting my truck off, since it should still engaged for a bit while everything's hot...but I don't really know how hard it should be to turn, so I'm not sure that'll help. The FSM has no info that I can find on how to test it.

 

well i dont think i have the balls to stick my hand in the fan while running lol! but any ideas on the power problem?

 

You might try it with a screwdriver. I don't think the clutch works unless the fan is spinning. I've never seen one that wouldn't spin while the engine was off no matter what the temp.

 

ok so i fixed the timing. and tried to see if i needed to bleed air out of the radiator i checked for leaks there was none and the coolant level stays 1 inch from the cap! it now over heats when in idle the truck has about 180,000 miles on it i think i need a new fan looks kinda small

 

I would try the new fan. Did it start overheating at idle right after you adjusted the timing or is that un related? I still have a feeling your gonna need a head.

 

well i went a got a new fan today. but it came as a pusher fan the box says to flip the blade and reverse polarity of the wires any ideas on how to do that ?

 

i got the new fan on and nada still overheating!