91 240sx coolant boiling out of the overflow tank ... HELP!!! PLS!!!

[espa.s13]

ok what i did was flush the coolant and bleed it. then i had air in the engine. so what my friend told me to do is take out the thermostat. so i did that and the engine runs great no problem at all. then i bought a oem thermostat and put it on. now the problem starts. when i go home last night from a friends house about 60-70 miles away. when i parked my car i heard that boiling sound. it was the coolant boiling over the overflow tank. i have new raidiator cap. new thermostat. coolant was good. can anybody help me .. dont know what to do ..

[180fan]

did you bleed the air out of the system before running it?

[espa.s13]

yes we did that .... it was running fine without the thermostat. i havent try running it again today.

[DrunkDRIVER]

from my experance with this...are u sure u bleed ur coolent system completely???

its alot easyer to bleed ur system if u had one of thses-->

using that from above, hook it up and warm up ur car and let it idel (bad spellin, i knoe) for 30 plus minutes..sometimes, there is still some air bubbles in the cooling system, even when u think u got it all.... my freind and i had the same freakin problem... and it worked for us...

plus it doesn't hurt to re-check ur themostate... just boil water and put ur themostate in it..see if it opens....

but i do really think its probably just some air bubbles....

Modified by DrunkDRIVER at 2:29 PM 3/11/2007

Modified by DrunkDRIVER at 5:47 PM 3/11/2007
Modified by DrunkDRIVER at 5:48 PM 3/11/2007

[K]

It does sound like air in the system. More specifically, how did you go about burping the coolant system?

I had the same issue when i replaced my water pump, but once i finally got all of the air out of the system, the issue went away.

KRM

[silpena]

i'm pretty sure u have a blown headgasket. Same thing happen to mine it would over boil into the collant tank and without the thermostat it would be find. i'm guessing its a small crack in the water jackets. All the pressure from the pistion is being pushed out into the coolant systems cuasing ur pump to stop and ur thermostat to stay closed from wat i think is right? I think coolant system is running at like 14-18 psi so i guess addig another 100 psi from the pistion is gonna have some effects. I check that if i were u.