questions about overheating

[1TuffSupra]

Ok I searched but couldnt really find exactly what im looking for. After swapping out another hose that busted on the car Im still having overheating problems. Im pretty sure that its not the headgasket, there isnt any oil in the coolant and no coolant in the oil plus the car isnt smoking whatsoever. Plus I changed it when i did the swap. But the car keeps loosing coolant. I drive the car for about 10 min and the coolant starts spilling out the overflow bottle and the heat goes in and out. None of the hoses are leaking, all the clamps are tight, the radiator cap seems to be holding pressure. I plan on replacing the thermostat and the radiator cap tommorrow, but is there anything else I should check? With all the leaks that Ive had with hoses busting left and right since the motor swap, should I have the cooling system flushed anyway? Im open to any suggestions. TIA

 

[Reign_Maker]

On your over flow bottle, do you have the filler hose on the correct nipple? When I bought my first supra, I was driving it, and it over heated and when I popped the hood, coolant was pouring out of the over flow, and when I took off the cap, someone, for some reason, switched the hose, so when coolant was coming in, it was being pushed out...

 

[aznwaterboy]

you might have air bubbles in your system, try burping your system. run your car without radiator cap, and heater on at max, for a few mins and then you should see air bubbles come out of the radiator, fill with coolant as necessary. is your thermostat working correctly too?

 

[Nick M]

It is rare, but the impeller on the water pump could have seperated from the pulley.

If your thermostat sticks closed, you will have very little coolant flow, and overheat also.

 

[Reign_Maker]

Oh yeah, burp it... Make sure you have the front of the car higher, general rule is to have your radiator cap higher than the back of the motor..

 

[CBLEGUY]

Ok.. I just went through this myself. if you search, you will see many threads a this particular topic. My best advise is to go through you coolant system with a fine tooth comb so to speak.

1. thermostat
2. fan clutch
3. aux fan sensors (are the fans coming on?)
4. burp system (steep angle make sure heater is on full blast)
5. repeat 1-4..

these cars are very sensitive to cooling, and any one of these, and then some can cause this problem. The problem just gets worse and worse the longer you run it without fixing...

 

[CBLEGUY]

oh yea,and rad cap as well..

 

[1TuffSupra]

ok, thanks a lot guys. I will get it done asap! Just wont be today though, its snowing out there and i dont feel like being in it. You guys basically confirmed what I had been thinking anyway. I also see that autozone has a 160* thermostat any of you guys try using that one?

 

[aznwaterboy]

i use the 180 degree one because i thought higher is better, but its not. doesn't really matter i guess, the thermostats will open at the degree setting so i guess 160 is better if you want a cooler running car

 

[Josh21040]

my car is having the same problem coolant coming out of overflow, and the fan clutch was deffinitely bad. I changed it, but its still doing the same thing. I'm going to change the waterpump too. Could that be whats wrong?

 

[lagged]

pressure test the cooling system.

check to see that it holds ~15-17 psi (our system calls for a .9 bar rad cap which is something like 13.4psi?)

if it doesn't, find the leak.

if it does hold the pressure, release the pressure and now let the car warm up with the pressure tester attached. let the car warm up and rev the engine. make sure that the pressure does not exceed .9 bar by much. if it goes much above that and jumps up rapidly you might have combustion gasses pushing into the cooling system.

that equates to either a blown headgasket or cracked head/block.

 

[Josh21040]

I changed the water pump and burped the system. I drove it around for alot longer than it took before to overheat and the car ran fine. I am going to find out tommorrow if it is still blowing coolant out of the overflow. The car was doing that before and it wasnt overheating.

 

[7Mboost]

500+ hmm is that c16 I smell? :biglaugh:

 

[bondie]

check your waterpump . . . it should look like this:

one i removed lately looked like this:

 

[Reign_Maker]

HighPSI: 500? huh? Whaaa?

Bondie: HOLY SHIT! I've seen some worn out water pumps, but DAMN! *shakes head* damn!

 

[ForcedTorque]

My car had the same issues, and it turned out my radiator was clogged. I pulled my drain plug on it, and it resembled a small piss stream. If your coolant doesn't drain pretty good, have that radiator checked or replaced.

 

[Supraboy89]

yea i agree with forcedtorque check the radiator for cold spots. I had a overheating prob with my supra. it puzzled me for the longest time until i finally pulled the radiator and checked it