. I have changed the T-stat,Radiator,fan (electric) water pump all this winter. The fan was a new thing as of last weekend. After that didnt do anything i tried backing off the timing. I have tried 5deg and 8. None of that helped so i pulled the T-stat out and tested it in boiling water. It was stuck so i cut the center out of it and put it back in thinking if that was the issue i would see a change. Nothing. The truck is now running hotter then ever. Could my water pump be pooping out already? I havent had this issue ever with this truck and the radiator that was in it when i got it was bent and the fan had smashed in to it like 3 times. I replaced it cause the guy i had do my locker said he would do it and that it was leaking(it was the cap)

Anything i should do now? Im aboutto swap out the radiator with a newone thats here and a stock fan with new shroud a new fan clutch and use the electric one too! I am sooooo sick of this!


Thanks
Russell

 

IS it burning lean? How's the engine actually run?

Not sure what you mean by drilled a hole in the T-stat? If its wide open the engine should take a damn long time to heat up...

I'd replace that Thermostat .. not sure what you did to it but get a new one anyway.. before messing with more $ on pumps and radiators

 

What exactly is happning to show you it's overheating? Is it boiling over? Temp gauge?

 

ok by cutting the center out i mean its basicly a washer made out of the t-stat.Its open all the time. Its still heating up.

the temp gauge is showing it and it will boil over heading up the hills to a trail and at elevation it has to cool all the way to finish a trail anymore

 

oh and i forgot. I never had a fan shroud for the 6 years between buying the truck and getting it back. It was smashed in the wreck. when the guy did the radiator he put one on and it still got warm but it rubbed the fan sometimes so i took it off. It was fine for a few months. but all this started after that guy worked on it. I have a webber down draft and it seems to run kinda rich but with the timing advanced it runs amazing. The slower it gets the faster it heats up in town but the more i advance it the harder it is to even drive up in the hills

 

What exactly was done to the truck?

 

maybe you could be suffering from air in the cooling system? might have to burb the cooling system. do a search on "burbing" or "air in the coolant"

 

I was thinking the same thing...

 

Overheating at slow speeds means not enough air flow, either your fan is not pulling enough air or similar. Have you pressure tested the cooling system? What sort of radiator was installed?

 

Does your cooling system hold pressure? ie. ~15 psi after engine is warm. Squeezing the radiator hose is a quick way to verify that the cooling system is pressurizing properly.

It almost sounds like you have no coolant circulating in your block.

Question to all: Does the fan clutch solely rely on coolant flow to warm it up for proper operation?

 

Only indirectly. The stock fan clutch has a bi-metal coil on it's front face that picks up heat from air flowing through the radiator. As it heats up, it twists the center shaft and that varies the internal valving to restrict silicone fluid flow inside and that makes the clutch stiffen up and spin the fan faster. Not uncommon for that center shaft to get stuck, I had to pop mine loose with a pair of pliers so it moved freely.

 

Replace that t-stat, get a fan shroud, and check your fan clutch. I'd also hook up a mechanical temp gauge or use an IR laser temp sensor gun to see the REAL temp. And check all the usual stuff like kinked hoses, air in system, etc. I would reset your timing back to the recommended setting...it's just going to mask the real problem and make your truck run like crap. Good luck.

 

try a radiator cap too, pressure leaks are a PITA.

 

X2
sounds like you're not getting the correct pressure or you have too much water vs coolant. I would start with squeezing the radiator hose, if it's floppy then check the mixture of coolant to H2O (should be ~50/50)
Then replace the radiator cap. If it still does it, look into a bad water pump.

 

Its holding pressure and i i dont know why id see an air pocket after the winter of driving every day.

I have an electric fan now,factory radiator,Replaced the cap because that was what made the guy wo worked on it think the radiator was bad. the water pump was replaced and as of now there is no thermistat at all just the outer ring to hold the gasket in.

It started out as only doing it at elevation and now its doing it in town. I used to be able to drive around and it would run right below the mid way mark. As soon as i climb in elevation it will just jump up.Im not sure the exact elevation it does it but its pretty quick. I tested the t-stat by boiling water and it was sticking. It was late and i wanted to test for the problem and just cut the center out. The electric fan is set to come on as soon as possible now to see if that helps. everything in the motor or attacthed to the motor is less then a year old. I replaced the motor in Oct. of last year and have replaced anything i could think of over the winter. My heater sucked when i put it back togeter so there was a bunch of flushing of the system and replacing parts to get it working. Now the heater gets super hot........at this point so does the truck.


Whats a better way to bleed air from the cooling system? is there a better mix of coolant and water to try? 50/50 has always worked fine.

 

Does it get hotter when the heater is on? Maybe that's why you were only seeing it at altitude...

http://www.4crawler.com/4x4/CheapTri...tml#Thermostat

 

kinda sounds like a NEW radiator will fix it.

 

So are you saying that the NEW radiator i put in less then 6months ago is now bad?


Troy, the t-stat is out and after driving it some today the heater is helping but not much at all. It didnt over heat sitting in place for a while. I drove it super nice so im thinking one option could be a fuel. Maybe my webber is leaned out top end cause i see the heat rise when im putting load on the motor more then normal. yesterday i had my 36's in the bed and drove to denver. today i didnt have anything in the truck and was easy on it. Maybe a lean condition is causeing the motor to heat up too much. I know nothing about webbers but will spend time to tweak with it if i know what screws to play with.

My friend said something that has me scared. He said when his 22r headgasket went it acted like this. He said the gasket had a small hole that would allow air in to the cooling system but wouldnt let enough coolant in to see smoke. He said about a week later the headgasket went all the way. im starting to wonder if maybe the 2 times it ran hot before i figured out the fan clutch had crapped out caused the headgasket to blow? Im just out of ideas here. Everything has been replaced and less then a year old.

 

hmmmm...i think everyone is starting to run out of suggestions. i would go back to the basics. check radiator flow, coolant flow from engine, maybe do some work with an ir themometer. make sure the fan is pulling air in. guy i knew once, either installed the fan backwards, or got the wrong fan, and it was trying to blow air out. kind of counter productive. it baffled a bunch of people for the longest time.

 

Ok so heres what happend. Talking to my dad and a few others and they were thinking lean or timing. I thought back and the carb was on in the heat and the timing was way hotter then. I had to drive the truck to denver and thought just to be stupid and try something new i drained all the coolant out of the radiator and filled it with straight water thinking it will cool faster so if it gets hot its less time on the side of the road waiting to cool. It helped and more then i thought. I got about 90% of the way before it really started to climb. I pulled over and smoked and it was cooled off below normal temp. no boiling over....

I got to the VW swapmeet and bounced this off everyone there that could turn a wrench. I heard water pump a bunch and maybe a bigger fan. On the way home she got hot and ipulled over to let it cool and she boiled over on me. Because this is doing it on highway im thinking water pump. I stopped at the parts store picked one and threw it in at the house. Went for a drive.....nada everythings the same. The water pump did have a good amount of play in it but now i couldnt get more then 5 miles and it would jump up.

I turned the garage upside down looking for a fan clutch. I came accross a fan set up and seriously ripped the electric one out and pitched it accross the garage. Threw the stock one in and drove it. Heres what i have now the truck will get up to normal temp from what i can see(by now its cooler then the day was) it doesnt cool off doign highway speeds but it will hold temp. it doesnt climb with or with out the heater. I have to unload the bed of stuff throw the wheeling stuff in the back and im going to drive it tomorrow around town and see what happens. If it over heats again im going to pluck the radiator and go back to toyota or a radiator shop and get a new one again. The electric fan will be going in front and set up as a pusher fan to aid the cooling. Im going to set it so that it comes on a tiny bit above normal temp or at normal temp. With any luck i have it fixed and can move on to my rock doors and charger stuff. If i cant figure this out by the end of next week im selling the truck to a friend and getting an 01-02 4runner (fingers crossed on the fix cause i really do love this truck)

I grabbed the laptop and went out side for a bit. I have a tiny puddle under the truck....this is new. I looked and its coming from the drain.....im thinking the gasket may have been letting air in....i sware if getting a new drain plug for the radiator or even just a gasket for it makes this all go away im going to flip!!!!Oh well i guess i know the parts are now 1day-6months old. :rolleyes: