mach5racing4

i have been working on my 95 gt and had it get pretty hot so i decided to flush the coolant system, replace the thermostat (a 190) and install a summit overflow tank, i put the tank in and left the breather hole on the tank open and left the low coolant connector unconnected. i got it all back together and started bleeding the system and it starts to warm up and sucks some coolant down, then it overflows a little then its fine, but then as soon as it gets warmer but before the fan goes on the radiator starts to boil over. the owner before me replaced the radiator and hoses but i dont know if its the right radiator. its normal size and about an inch and a half wide. i was thinking maybe it could be a bad thermostat or waterpump. has anyone run into this problem before? any help would be great guys. also the car has 60,000 miles. thanks!

bobbyboura

you have a blockage some where maybe get a bigger radiator ot check the heatercore

mach5racing4

whats the best way to check the blockage? compressed air?thanks

skielk

Take the cap off and run the car until it gets hot enough for the themostat to open. Look in the filler cap and see if you see bubbles in the system. You prob. just have an air pocket in the system.

mach5racing4

thats what i was doing when it boils over. i tried to bleed it. thanks

r.barn

make sure T-stat is not in backwards,
did that once by mistake, gave me all kinds
of strange overheating and pressurized coolant system
problems.

mike.0621

I would take out the thermostat and run it with the cap off. if you see the coolant running through the rad then you know that the water pump is fine. I had the same thing happen to my car and it was the water pump. if it is flowing fine and the veh does not overheat with the thermostat out then i would check the thermostat for proper opening and closing, if that is working fine then i would wait until the car gets warm and then turn on the heat, if you do not get geat in the car then you might have a plugged heater core in which case you can try to connect the two heater core hoses together to bypass the actual heater core. if it still happens after that then i would say that you have a blockage. I hope this helps!!!!! good luck.

mike.0621

i put my thermostat in backwards too (nobody said i was bright!!) and it really screwed me up and overheated in like 10min
that sucked!!!!!

mach5racing4

ok thanks guys i will go check those things and let you know

mach5racing4

i removed the thermostat and ran the car and it took in more coolant and seem to be sending all the air out, the fan cameon and all looked good. but then all of a sudden the radiator started overflowing so i put the cap on and it just kept spilling out the overflow so i shut it down. i cant figure it out, could it still be a bad waterpump? i also boiled some water and dropped the thermostat in and it didnt seem to open at all.