Anti-freeze/Coolant Problem!

[cjman15]

Today after driving home on the highway for around 20 minutes, I pulled up to my driveway and I look under my engine and the coolant is just pouring out onto the pavement. I ran to get a pan to catch some of it. When I come back, I popped the hood and check to see what happened. It appears that the coolant got so hot it got expelled out the overflow at the top of the reservoir. My car is a 4-speed auto, so the entire trip on the highway I was taching around 2500rpm... but my temp guage was reading normal the entire time, even before pulling into my driveway.

Anyone know what could have caused this???

 

[bhuff30]

it is wired that you say the temp was normal the whole time.
Make sure your cooling system is pressurizing. If it doesn't get pressurized, it could cause that.

 

[blkstangman88]

my car did it after a long trip from AZ to WA, but that was just an over heating problem that was easily fixed. urs, cant think of anything right now, expecaly for just 20 min of driving.

 

[blk92stangg]

Maybe your cap is no good. Like was mentioned, if the system doesn't pressurize, the boiling point will be much lower, to the point it could boil over at a much lower temperature.

 

[91_4ourBanger]

im having the same exact problem with my 4 banger, could it possibly be the radiator cap?i also have almost no coolant in my reservior now

 

[HISSIN50]

swap the cap

 

[cjman15]

Thanks for the input, i'll be sure to check it out... could it possibly be the thermostat malfunctioning?

 

[legomaniac32]

i would go with the cap..most garages have a tester to check if it is holding pressure, and i think its free to test. caps arent that expensive. they really should be changed after you flush your coolant.

 

[HISSIN50]

when the motor is reading hot (i.e. 180 or above if you have a 180 stat, 195 if you have a stock stat, etc), squeeze the upper radiator hose. if it is firm, the stat is at least partially open (be careful and all; the hose is HOT).

you could also take the cap off (cold motor), and start the car. let it warm up. the coolant in the rad will be mostly stagnant until the stat starts to open. then you should see coolant flow from pass side toward the driver side (lookin through the rad cap hole). if it does not ever flow or the level does not move, that suggests a stuck stat.
if i did not mention it before, i really like the Mr. Gasket stats. balanced, opens fully sooner than others, and has a bleed hole. 10 bucks at the speed shop. good luck.

PS. the way i look at a cap - if i dont remember the last time i replaced it, i do it (preventatively). a messed up one can mess with you. good luck.