Pretacopower

I ran a search but it seems like most of them were referring to overheating after driving for awhile.
My '87 starts overheating almost as soon as you put it in gear and start moving. However, it will not overheat while idling.
Any ideas? My mechanic said that it doesn't look like a headgasket problem. I'm going to replace the t-stat just for good measure and we'll see what happens, but if anyone knows of anything else to check I'd greatly appreciate it!

seaflea

have you checked the fan clutch? If its locked up it may run a bit warmer.
Also make sure there are no bubles in the system. It seems that on the 22-re there can be a little pocket of air in the T-stat housing right where the temp sensor is. This can cause some strange problems.
Good luck.
let me know how it turns out.

castrolSi

Check and make sure that it is, in fact, over heating. Mine takes a good while to
get warmed up. Maybe you have a gauge problem? Is it really hot?

~castrol

Fahrenheit 451

Does it do this in all weather temperatures? On the 22re's in that era, the thermostat is after the heater core and when temps outside cool down the thermo gets a cold water dump on it early on when the vehicle starts. Then the engine temp will climb until the thermostat finally pops open.
Surf around and check for info on the two stage thermostat that you can get for the 22re. It will fix that particular problem. You can also get around that by drilling one or two small holes in the rim of the thermostat. Opinions vary on the size of the whole, but generally something in the 1/16-1/8" seems to be the standard.
It could also be the fan clutch, plugged radiator or maybe a plugged catalytic converter. If you keep driving does it overheat and boil over or does it eventually drop back into the normal range?
Not to be a doom crier, but having had a couple 22r headgaskets replaced, one thing I noticed was that early signs of failure was the engine would overheat early while driving then drop in temp. Once the engine temp came up and the head "swelled" the exhaust leak into the cooling system would stop. Let the truck cool down and would heat up early on again. All those "heat and cool" events keep wearing at the gasket.
Did your mechanic do a coolant test to check for the presence of exhaust? If nothing else it could bring piece of mind. I think somebody on here said before you can get a kit at places like Autone.
Good luck!

SoCal4Running

Sounds like a wiring issue to me. Frayed wire rubbing on something when you start to move, or the motor shifts, ect.

How old are your cooling accesories, water pump, radiator, thermostat, fan clutch, hoses????

Pretacopower

Thanks for all the replies!
I haven't looked at the truck yet since it overheated....my mechanic took it for a test drive after they got the engine running (no injector pulse) and that's when the overheating problems surfaced. He called me to let me know. I'm going to tow it home tomorrow and try to work on it myself.

SoCal, you might be on to something. My wiring system is BUTCHERED and I mean butchered. There's cut wires all over the place. I bought the truck for 500 bucks and someone definitley had their way with it somewhere down the line. I really could'nt tell you how old everything is...supposedly the motor was rebuilt 500 miles ago (the previous owner gave me the reciepts) but my mechanic said it doesn't look like it ever was.

Seaflea-I haven't checked the fan clutch, but will be sure to do so. I'll let you know how everything works out.

Thanks again for the replies. I'll keep them in mind when I start wrenching on it tomorrow We'll see what happens.

SoCal4Running

If your harness is so jacked you had no injector pulse, you definatly do not have a overheating problem. Check all the wires or just install and aftermarket guage.

jimbo74

you might want ot replace the tstat with the 2 stage one from toyota.... look at this http://www.4crawler.com/4x4/CheapTri...tml#Thermostat