Recently noticed my 85 22r was running a bit hot, found the water pump dripping from the weep hole. Since it was overdue for a timing chain, I tore it down and put in a chain, tensioner, water pump and oil pump. Since then, it wants to overheat at high rpm. Will idle or drive around town with no issues, but climb a pass and the needle climbs till I get worried and let it idle till it cools. Since its 22 years old I figured cooling system problem, replaced fan clutch, thermostat, and a new 3row radiator and new hoses. Runs better, but needle still climbs at high rpm, so what ever condition is producing the heat is still there, but the radiator is helping dissipate it. Popped the valve cover, at TDC the cam mark is at 12:00, the chain mark is at 11:45 like its supposed to be. Waved a propane cannister all over and cant find a vacuum leak. Egr system checks OK, timing is a 0 with both diaphrams disconnected and plugged. Plugs look great, has good power and no pinging with load. Burped the cooling system several times. Did a chemical test for exhaust gases in the coolant, negative, and its not loosing coolant. I am out of ideas, What am I missing? Is it possible the chain is a link off? Even though it matches up top on the cam, could it be off on the crank? The only thing I can think of is some kind of vacuum leak only at high throttle? Maybe rebuild the carb? Before I throw more parts at this, thought I would consult the gurus here. Thanks for any tips. I am totally frustrated.

 

Go with the 2 stage thermostat and see if that helps. Had a similar problem and it appears your problem occurs whe nthe truck is under load.......

 

Hmm, not to dis your advice (especially since you are the only one to respond in two days) but I have tried several thermostats that I checked on the stovetop before putting in. Even tried one that I drilled a small bypass hole in, no change. Hard to imagine that another different thermostat would change anything, guess I could go price a two stage though. I may try with no thermostat at all just to see what happens (carbed, not EFI, so no ECU to worry about). Its probably going to end up being something stupid and simple that I am just missing, like a cracked vacuum line or bad electrical connection (I hope). Thanks for the suggestion though.

 

i thought the mark on the cam sproket should be at 1200 and the bright link just slightly to the left not at 1145? That sounds too far retarted, im no expert at this but its what i was told

 

Are you sure you have a 50 50 mix of anti freeze and water? Too much water and it may be heating. I'm dropping a good link on what the 2 stage tsat will do for ya. Do you have the shroud on the radiator? If not that might be hurtin ya. I saw you put in a new fan clutch but have you tested it yet? Warm the motor, turn it off, grab the fan blade and have someone start it you should feel the drag in the clutch. This method aint for the faint of heart and is dangerous if you aren't carefull. Be sure nothing rotating is gonna hit your hand or wrist. Have your buddy shut the motor off before you let go off the fan. Have you back flushed the block? Does it cool down if you turn on the heat? Oh and I thought the cam was more like just barely off of 12:00 but its been a while since I put mine back together, I remember it being off just enough to look funny.
Jim

 

Triple check your distributor, probably off a tooth or two.

 

Mine was overheating also mine is a 22re and I put a new OEM thermostat in and flushed the radiator with a cheap kit from auto parts store let the hose run for a while and craked it up and let it go threw the heater core and put new coolent in and it fixed it. How far is the niddle going up on the gauge? Mine goes up about 1/4 up half way when I got A/C running.

 

Oops forgot the link. The dual Tstat prolly wont help ya roll down till you get to the tstat info.
Jim

http://www.4crawler.com/4x4/CheapTri...tml#Thermostat

 

what brand waterpump did you put in? did you check your ignition timing?

 

It was a cheap aftermarket pump, do you think it might not be moving enough water? I suppose its possible. I am running 50/50 with the shroud in place. Needle climbs to the top white line on long steep hills before I stop to let it cool, never did that before this last work. Timing is at 0 degrees with vacuum lines plugged. I will try the dual stage themostat (thanks for the link) but its going to be a while before it gets here, dealer wanted 45$ for one, found one on line for half that. Think I will change out the bottom radiator hose too, it feels soft maybe its collapsing. Thanks all and keep the suggestions coming.