ok this started off as my truck had gotten hot twice, both times it was pretty cold out (like low teens to possible single digits), had to pull over and let it cool off for a few mins, (long enough to get the needle far enough away from the red to feel semi comfortable) i would start driving again and the needle would start rising again and then quickly start coming down. so today i do a chemical/water flush, put in a new t-stat refilled with new coolant/distilled water. burped the system, then got in my truck and drove 50 miles all was great, then my truck sat at roughly -1*f for about 5 hours then i got back in and started driving home, the temp gauge slowly comes up to almost the red im going about 65-70 miles per hour, i push in the clutch and start coasting looking for a place to pull over and all of a sudden the gauge starts dropping right down to where it should be and then it stayed there the rest of the 50 miles back home.

i thought for sure that the t-stat was the problem before, but now it did the same thing after 50 miles on a new t-stat? am i missing something here? or could it have been an air bubble that caused me to have a problem when leaving to come home? that seems kinda hard to believe as well after 50 miles of highway driving with no issues previous to this. is it possible a t-stat can fail after only 50 miles?

 

your water pump might be going out that is a weird overheating issue i have never seen before you could check the temp gauge itself see if its bad also when it overheats feel the radiator and the hoses to see how hot they actually are

 

I get a similar problem. I'll just smack the dash and the needle drops...whats that mean?

 

I would most likely say the guage and/or sender are being funny. Could even be something as simple as a dodgy connection. Check to make sure that your engine isn't actually overheating first however..

 

You didn't post the type of engine, but it sure sounds like the 22RE Temperature Overshoot issue:
- http://www.4crawler.com/4x4/CheapTri...tml#Thermostat

 

yes it is a 22re i forgot to add that in my post. and it is getting hot the first two times i stopped it started boiling over this last time i did not come to a stop so i don't know if it was boiling over but the air out of the heater defiantly got hotter so its not the gauge operation. 40 bucks seems high for a thermostat but the link 4crawler provided sounds like it very well could be the problem, maybe i should try just drilling a small hole in the t-stat to see if that fixes the problem of try turning the heater off if it starts getting hot again and see what happens. if that seems to fix the problem then i will get the 2 stage thermostat

 

ok this is my problem, it started to do it again on me today and i turned off the heater and the temp gauge started dropping

 

check-out the fan clutch? I had this problem once, truck was ok. on flat surface but soon it started to go up, the temp. neddle was faster, one day I pulled the thing out, opened and throw some bearing grease in it, problem solved. hope this helps.

 

mine was doing this too, typical 22r temperature overshoot, I fixed mine by drilling a 1/16 hole in the base of the thermostat. Now it does not go past slightly below halfway.

 

That sure is strange! Usually u turn the heat ON to help cool a motor, as the heater core is basicly just another smaller radiator....

 

the problem with the 22r the way I understand it is that when the heater coolant returns back to the engine it dumps right before the temperature sensor/thermostat. Causing the actual coolant temperature to be masked momentarily leading the thermostat to open later resulting in a higher engine temp.

This is why toyota made the dual stage thermostat, so the differences in the coolant temperature would be minimized, instead of going from say (not at all accurate) from 220 -150 your going from 200 -180 -150

 

Sounds like the 22RE temperature overshoot problem:
- http://www.4crawler.com/4x4/CheapTri...tml#Thermostat

 

it sounds like when i ran mine with just water and no anti freeze and the thermostat got frozen. make sure there's plenty of antifreeze. I kept forgeting about it and then all of a sudden it was 10 degrees out. I was lucky nothing broke.

 

did that affect your warm up times at all?

 

Hey EZrider......how many miles are on that radiator(over 150k)? And has anyone ever used stop leak stuff in it before?

 

haha - funny thing - that JUST happened to me this morning in my 4runner with the 4.3L - I didnt check the anti freeze (like a dummy) and yup, pretty low. So had to borrow the fiances car to go to bi-mart to get some. problem solved.

btw its for sale!

 

yes a little. hard to tell because my choke is fubarred anyway, add that to a fan clutch that was bad which I just replaced.

 

OK so I have a 92 3vze and last night while I was driving, the water temp was right at normal, but no hot air was coming into the cab. after driving for a little while, the temperature started to increase, and just before it started to overheat, the temperature went down quickly and I could feel hot air coming into the cab. It kept fluctuating like this all the way home. The only things I could think of were the water pump, T-stat, or perhaps some sort of plug somewhere. any thoughts?

 

well hopefully it doesn't have too much affect on warm up time as we will probably pretty much stay below 0 here until spring. but i think im going to try drilling the hole before i spend 40 bucks for a specialty thermostat. the funny thing is i don't remember having this problem last year but then again i hardly drove the Toyota last winter, my ford 7.3 power stroke needs new battery's so one it got cold out it needs a jump to start and right now i don't have 200 bucks to spend on battery's. it seems to be worse after putting in the new thermostat, but the last one had a very small hole in it and this one does not. now its doing it almost every time coming from an cold engine. when i get in it and start driving when the temp gauge starts coming up above where it normally sits i turn the heat off or almost all the way off and it will come down and then i'm fine for the rest of the trip.

 

t stat should have very little affect on your heater, sounds like the water pump or possibly air in the system. but i don't know much about the 3vze