Thats what I was worried about - I bought the OEM Toyota T-stat as I thought it would be better than some aftermarket one.

I am not confident yet I have all of the air out of the system, so that being the easiest I'm going to give that a shot after work, try to get the truck on an incline etc....

Blowby on the HG though - that sounds scary. The truck ran perfectly fine before I changed the T-stat, however the old one was gutted to it ran open all the time.....I'm hoping he didn't gut the T-stat to avoid a more costly fix

 

sadly, he might have. put your new tstat in boiling water to make sure its working. if so, it will open. if not, it wont open. and yes, blowby on the HG DOES sound scary. im glad i have the 22re and dont have to worry about HG stuff regularly. do a compression check on all the cylinders.

 

OK - So i burped it as much as possible tonight, needle was just below the center, looked good. Reservoir/overflow bottle had lots of fluid. I drove it around the block and watched the needle soar towards the hot zone. It seemed to stop right before it hit the red, but I needed to limp it back to my driveway...hope that didn't hurt the HG.

Anyways, coolant was leaking a bit from around the top hose clamp, and the rad cap (probably cause it was so hot, never happens when its slightly cooler even) But I felt the top hose, it was hot. Felt the bottom hose, its stone cold.

So that means the T-stat is still not opening right? Its a brand new OEM stat...POS

 

take it back. tell them it doesnt work and you want another one. somethings not right... you did flush the cooling system right? and the overflow bottle is only supposed to be maybe 1/4 full. maybe thats your problem. test the thermo in boiling water before you take it back. ill go grab my service manual in the garage and see if it says anything about your problem.

 

I'm pretty sure i've flushed it right. I've left the cap off, squeezed the top rad hose until no more bubbles surfaced. Did this twice last night, then once tonight parked on more of a hill.

The heat got pretty high last night, so I think the bottle filled a bit more from overflow alone....explains why it was taking more and more fluid.

I should have felt the lower hose last night. I finally did tonight, the hose was extraordinarily cold right after I shut it down hot.

 

If the t-stat wasn't opening then the top hose should not get hot. Or it would take a long time and slowly warm up just because the coolant on the other side of the t-stat is hot. The top hose should be hot and the bottom should be cold. The hot coolant will enter the radiator via the top hose. The bottom hose is the exit for the coolant so it should be cold. Now when you say extraordinarily cold, what does that mean? Like the exact temp as it is outside? The bottom hose should feel warmer than the outside air but no hotter than about 100-110 F. If it is the same temp as the outside air then I would think that you have a blockage in the radiator itself. I know that you said that it was just replaced but maybe some junk already clogged it. As for burping the system, I would park the car facing up hill. While its till cold, pull the radiator cap and let it fully warm up. If there was air the level will go down. You should be able to see the coolant moving around when the t-stat opens. Like Ozzie said, check your t-stat in water that is about 190 or so. The t-stat should open before the water boils. I could be that the t-stat is not opening until the temp is getting way hot. Hope this helps.

 

Pulled the T-stat today and put it in a pot of water, it opened before it started to boil (about 180 degress)

So working T-stat. Im wondering about the Rad now. I put the T-stat back in today, filled the coolant, thought it was running great. Then took it around the block and it crept right to the redline. It doesn't go into the red, just before it on the needle - is that ok or way too far?

I pulled in the driveway and felt the bottom hose, and its still really cold though, so is the bottom of the rad. I wonder if the rad is clogged? It looks new to me. It should be at least warm at the bottom though no? The top of the rad and upper hose are extremely hot when I am trying this.

 

The gauge should not be going into the red or even touching it for that matter. Maybe the belt on your water pump is loose and slipping. If the bottom hose on your radiator is that cold it sounds like there is no coolant circulation. Have you tried sticking a hose into the radiator to flush it? It's possible that the radiator already got plugged.

 

Awesome thanks for your help!
Its been a blizzard here tonight so still need to flush the rad, but its next on my list....
On top of getting a compression test...I'm worried about the HG now seeing how it looks like overheating has been a problem since the previous owner had it.

Thanks for the tip and help though! I will report what I find as soon as I can get at it