engine overheating?

[fullaaa]

hey just the other day i stopped my car and noticed this bubbling sound so i pop the hood n the overflow bottle was going bezerk like it was gonna pop off n spray hot green juice all over me. anyway its happened a few times since then and my temp guage is dodgy so if anyone has any clues to wat it is feel free to post ur answers. My mate said it could be a water pump but im no mechanic so ill leave it up to u guys to help me out before i go forking out money to fix something that dont need fixing

[Hairy Eater]

thermostat not opening... blocked radiator cores... thermo fans not working... blown head gaskets... Once the green coolant level gets low in the engine and is lower than temp gauge sender unit, temp reads lower than it really is....

[fullaaa]

mmm thats odd coz its not using any coolant from the radiator. and i check the overflow bottle once a week and it very rarely needs topping up. its only losing coolant when it bubbles from the overflow bottle and when it turns to vapor/steam so i dunno wats wrong with it ?

[ScottB_33]

You should be able to run the vehicle with the overflow cap off and watch the coolant level. If the coolant is spewing out the bottle then there is some major problems happening. My guess is that the headgasket has gone on the exhaust side of one of your heads, and what happens is that the exhaust gases superheat the water before the fan can be switched on and cool it down therefore causing the water to boil. A TK tester is used by mechanics to check for exhaust gases in the coolant water. I would suggest seeing your usual mechanic and getting this test done.

[mishiss]

same stuff happened to a mate of mine. Thermostat was closed shut and the switch for the thermo fan was stuffed.

[PaRaDoX]

could also be a blockage in the radiator, my girlfriends brother had it happen to his car... blew the head... worth gettin checked out asap before too much damage is done..