overheating

[945.0]

im in a bind. my uncle gave me a 94 lumina 3.1 v6. just replaced the head gaskets. well it overheats.fans dont turn on. the thermostat is bad so i ran the car with it out. still overheats. the upper rad. hose was ready to burst with the thermostat in after removing it and running it still was squeezable but as it started to ping hot again the hose was solid again. pop the rad. cap and it has a shit ton of pressure and gurgles into the overflow tank. any ideas? on why the hose is solid and has that much pressure.

 

[vermilion]

ok so all the cooling affects of this car have quit. thats why its overheating. simply, do not drive it. check fan fuse, fan thermostat, or fan. change the radiator thermostat. if thermostat is closed it will build up pressure. its binded.

 

[945.0]

not driving it needs brakes too. its sitting in the driveway. but like i said i took the tstat out and ran the car and its still has the same problem. i know its overheating due to the fans not kicking on and i have to change fuses relays to see if those are the problem for the fan not turning on. if not then the fans are bad. but why would the upper radiator hose be ready to burst and then when you pop the rad. cap its got so much pressure built up

 

[ademily87]

take a test light and check and see if power is getting to the fans. If it does it while idling and theres no fans at all running it can overheat rather quickly. good news is, its an older gm so if the fans ARE bad you probably couldnt walk 10ft into a junkyard without tripping over a fan set up that will work for it. start cheap and with a testlight. You'd be surprised how much of a differenc ethose little fans make when the car is just idling.

 

[CC'S95GT]

The car overheats when running without the thermostat because the coolant isn't staying in the radiator long enough to transfer the heat away. The thermostat regulates the flow of the coolant (how long it stays in the rad.) Put a 180* in. You may also need to do a rad flush to clean out the muck. Definately get those fans working though. Get a haynes/ chilton manual and look in the wiring diagrams for the cooling fan circuit.

 

[Nacho98]

fan switch for starters

pressure is caused by the heat. as temps go up, so do pressures.

 

[945.0]

did it even at cold start up too. im not worried about the fans or tstat my concern is the high amount of pressure building up on the upper rad hose. what causes that immediatily is my main concern

 

[RichV]

Your radiator cap regulates pressure. Most street cars have 16psi caps, race can be 20+. My upper hose feels very pressurized as well after a race, I run a 18psi cap. Heat creates the pressure, but if your cap is bad, it can be causing a lot of issues if it is not releasing pressure. Try a cap from another car if it fits. The fans will make a difference if you're stopped or in traffic, but when your on the go the fans hardly run. A lot of guys I race with don't even run fans at all.

 

[945.0]

im going to be trying a different cap tonight. would a head gasket create the pressure to?

 

[XxslowpokexX]

Run car with cap off..Let it burp the air out. You may need to bleed system..The hose will build up pressure with cap on normally ..Why so fast? That could be a million other things...But mnake sur eits bled first, make sure rad isnt clogged and get your fans working

 

[XxslowpokexX]

And sure bad head gaskets can cause that pressure..Youll generally see oil in your antifreeze though

 

[945.0]

no oil in antifreeze. fans i could care less about right now. thats least of my worries. i will try no rad cap and put a different one on too and see what happens

 

[RichV]

If the bottom of your radiator cap smells like exhaust, you probably have a bad HG. A buddy taught me that, but it could still smell from a previous failure.

 

[1997gtRioRed]

your cooling system might be plugged up somewhere internally. was stop leak ever used?

 

[945.0]

no stopleak used. and i never heard of smelling the cap. worth a shot though worst case is it stinks lol. stop leak is garbage btw.

 

[1997gtRioRed]

stop leak is garbage btw.

thats what i was saying. ive seen it plug up overflow tubes and blow open coolant reservoirs, and i could imagine that it could do the same inside an engine.

this is gonna sounds dumb but are any of the hoses pinched or kinked?

 

[945.0]

thats what i was saying. ive seen it plug up overflow tubes and blow open coolant reservoirs, and i could imagine that it could do the same inside an engine.

this is gonna sounds dumb but are any of the hoses pinched or kinked?

no i looked for those and check for leaks none of that happened. i got to run it without the cap to burp air out and going to change the cap to. update will come later tonight

 

[96TANGERINEGT]

Did u check it with a inferred heat gun yet? My gauge one time is almost all the way up then drops back down to the middle . Sometimes the stock gauges go goofy

 

[Tommy92]

It might be worth it to buy coolant boil/freeze point tester. If your coolant is no longer effective you can be overheating. Flush our the old coolant and add new 50/50 mixture.

 

[945.0]

Did u check it with a inferred heat gun yet? My gauge one time is almost all the way up then drops back down to the middle . Sometimes the stock gauges go goofy

no i did not.

coolant is brand new tommy92


i ran with cap off the while running still i put the cap back on. hose was NOT ready to burst it was normal as it should be. watched the temp guage and it was sitting in the middle for a good time it would go up a little and come back to the middle so the system is working properly. might have been a giant air pocket. now onto the fans to get them running again