Have you tested any of the t-stats? I always test mine in a pot of hot water on the stove. Use a thermometer and see if/when the t-stat starts to open and if/when it fully opens and compare that to the number stamped on the unit.

You could also try the small hole in the flange:
- http://www.4crawler.com/4x4/CheapTri...tml#Thermostat

And I only go with OEM t-stats now, have had a few aftermarket ones fail or not work right. I have over 10 years on the one in my 22RE now and it still works like new.

 

IS the mixture of coolant-water correct? at least 50/50? Are you putting the jiggle valve on the t-stat upwards when you install it?

 

I was gonna say, each time you have messed with the t-stat you have pretty much drained out the coolant. Usually when you refill the coolant system, I just leave the cap off because as it heats up and opens the tstat you get a TON of air that has worked its way into the engine coolant lines working its way out. Its gonna burp and bubble, drop and rise for a bit. You keep a hose or your mixed coolant close by and just keep pouring in. Eventually after about 5-10 minutes all the air will work its way out and you should be ok.

 

Sounds like a head gasket failure or the water pump impellers broke.

James

 

Not that this will probably help much, but to burp these things, you have to elevate the front end, start your engine and let it warm 'til the thermostat opens, turn on your heater to hot, and add fluid 'til she won't take anymore. It took me over 2 gallons to fill mine after swapping out rads.

And yes, the 3.4 is a worthwhile swap. I've put 70 000 kms (almost 44,000 miles) on mine and regret nothing about it.

 

Yea, I second that. In fact, I consider it less a burping process and more a push out the massive air pockets that you have all over the coolant system. It takes a good bit of time to do it, you just stand there and fill it, let it push an air pocket out, the level of coolant will drop dramatically..then add more. Repeat until done. Eventually, with the cap off it will just look like a slow moving stream of green or red coolant.

 

Sorry about the late reply, i dropped the runner for a while, frustration was huge.

The water pump is new and hg is new. So its not that.

Basically i gave up for now and put my hollowed out T-stat back in to go wheeling. Stays a little cooler then usual and warming up takes forever but its better then overheating.

I am waiting on my 6 inch lift with solid axel on its way.

So i will revisit after i do the sas this summer.

I also have to finish my other project, 71 ss nova.

I will update soon with sas stuff and overheating. My plan is to get radiator cleaned and a new oem t-stat with the burping nipple.

thanks 4 all you guys help.

 

If you're talking about a t-stat housing with a burping nipple, that won't help. Air goes to the highest point in the system. That's why you have to elevate the front tires. I used ramps under mine while the back end was pointing down the driveway. I swear the front bumper was 2 feet higher than the back. That's the best way to do it, otherwise the airpockets (assuming that's the problem) will sit in the other high spots in the engine.