Lakergrad

Having an issue with a thermostat not opening after complete rebuild. Truck is 93' 3.0 3VZE pickup. New motor, water pump, radiator, hoses, thermostat - complete new build. Have replaced the thermostat twice, but engine is still getting too hot because thermostat is not opening. Top rad hose hot, bottom hose is not. Heater working. Cooling system pressure tested good. Have tried to bleed air...

Ideas? Stumped.

Thx!

millball

Probably not truly full of coolant.

Disconnect top rad hose from rad, loosen hose clamp at the engine water outlet, rotate hose to vertical and slowly add coolant until coolant spills steadily from radiator top hose barb.

Then you'll know that it is very nearly full of coolant.

Lakergrad

Thanks Milball. Did exactly that this afternoon, based on previous posts. No luck.

Draining again and plan to boil thermostat, but since this is the second new one I've purchased, guessing it will be ok.

Should also mention it runs great without a thermostat!

Lakergrad

Stat tested good.

Odin

Frankly I'd just go get the Toyota OEM one from the dealership. Yes you will pay more but Japanese made is more trustable than today's junk in our local parts stores. Even Stant has problems these days. What is your time and labor worth. What happens when it sticks on you when your on a road trip?
Possibly pay me now or pay me more later.... Leaking hoses/ Towing/ Engine rebuild etc

Trents3.slow

Your not installing it backwards are you? The butt end(wax end) whatever you want to call it faces the block.

Lakergrad

No, I kind of wish I was at this point though...

Hard to argue with your advice. Think I'll pick one up tomorrow. Nothing to lose really.

arlindsay1992

iTrader: (8)

If the upper radiator hose is hot then what makes you think the thermostat is not opening? Whenever I replace the coolant in my 4Runner (22RE but the principles are the same) I run it at 2000 RPM with a towel in front of the radiator for a few minutes with the radiator about 1 inch less than full and the cap off so I can monitor everything. the top hose stays at ambient temperature until all of a sudden the thermostat opens and the top hose and top tank of the radiator are immediately hot and little wisps of water vapor come out the top of the radiator.


If the top hose is hot on yours then where is the hot water coming from?