s13 KA24de overheating out of no where

[Djmorfintime]

so I was driving my s13 home from work and it started to overheat it went up to about the line right before hot and then slowly started to come down a friend told me it clould be a blown head gasket so I took the radiator cap off n started the car n waited for bubbles but instead it just started to over flow n poor out the water/coolant I tied it twice n the same happened again need help don't know whts wrong any info wld be much apriciated

[brndck]

Check the basics.

Thermostat
Water pump
Clogged radiator
Coolant leaks
Bad temp sensor.

[Djmorfintime]

water pump is fine checked the gasket and its working fine I haven't checked for clogged radiator tho so ill give tht a shot

[racepar1]

So, it got hot on you ONCE and then the temp came down all by itself. Let's think about what can do that. A clogged radiator would be clogged all the time, it wouldn't suddenly un-clog and be fine. If your issue was a leak that would also not mysteriously disappear. Also the water pump cannot work intermittently. The one thing in the ENTIRE cooling system that opens and closes on it's own is the THERMOSTAT. It's most likely that the thermostat got stuck and jammed closed. Once it un-stuck itself the cooling system worked fine. I would start there and obviously check the rest of the cooling system for leaks or damage.

As for the coolant overflowing while running without the cap. When things get hot, they expand. Enough said...

[Djmorfintime]

yea ill look in to changing the thermostat because wht ur saying make sense its only doing it once a month or even longer than tht

[Driftwire]

I agree with the thermostat.. I would remove thermostat and start the car and check the hoses and see if they build up alot of pressure quickly if so then you normally would have a head gasket issue.