I have a 1992 runner with the 3.0 and I replaced the thermastat about three months ago. It didn't leak before I did this, so I replaced it and it would leak as it set over night. And so I got a new one and replaced it again and the same thing. Last weekend I replaced it again and still the same leaking.

My question is does the water pump leak around the same spot the thermostat is. I am thinking the water pump is leaking and it is coming out by the thermostat.


And is the thermostat gasket just that little rubber o ring around the thermostat. Or is there also a three holed gasket for the thermostat housing?

 

Bump up

 

yes, there is a gasket

http://personal.utulsa.edu/~nathan-b...10thermost.pdf

 

RTV will also work.

 

That's what I used the last two times. So does the water pump when it starts leaking, leak out by the thermostat housing?

 

I didn know about the "jiggle valve", so that has to be facing up. Could that be making it leak?

 

It could be. It might be impeding flow and causing the extra pressure to come out the gasket... I'd change that for sure.

 

I just replaced my thermostat on my 94 3vze with no leaks. There is a ring gasket that goes around the outer rim of the thermostat. There is not a three hole gasket that goes between the housing and the pump (at least that is what NAPA told me when I specifically asked, Rockauto also only has the ring for sale). Also the thermostat I installed did not have the jiggle valve. Make sure both surfaces of the housing and the pump are clean and smooth.

Haynes says to use RTV but the FSM does not. I did not use RTV and had no issues.

 

no, if it's the water pump it leaks further back almost under the engine if i remember right. if you have a skid plate and the thermo is leaking it will drip out from the skid. if its from the pump it will drip on top of the plate where the back of the skid attaches to the truck.

 

Yea I don't have the skid plate on. I also get a little going down the edge above the oil pan gasket and dripping off the rear of the engine. That's why I thought mabee it is the pump.

 

The thermo stat housing on these engines is made into the water pump. You should not be putting anything into the thermo stat seal area except that O-ring that it comes with. Theres no other gaskets made for it. Just an O-ring.

Generally when the water pumps "bad" or leaking it will show signs of leaking out the "weep hole" Which is located under nieth the pump pulley sprocket. But occasonaly they leak around the housing.

The thermo stat should only fit in there on way. And thats "spring in"

Theres also another place that leaks that alot of people over look and forget. Which is the idler pulley #2 for the timing belt. Which is located behind the timing cover n between the cam sprockets.

This pulley has a coolant pipe made into it which is what the upper rad hose connects to.

Where the pully bolts to the top of the engine has a lil rubber seal that will leak... and fools mechanics into thinking its the water pump. This will usually only leak if the engine has been "run" generally like a water pump.

 

Thanks