vtecwho

now my car loves to run really hot, not quite at the red mark but just below. when i add water to the radiator is runs normal but shortly after, the over flow tank is spewing radiator fluid all over. there are bubbles in the over flow after driving hard. is it possible that the gasket is alowing the air from the cylender to pressurize the radiator?? the leak down test held pressure at 10psi but leaked down slowly untill 10psi.

i was going to dive into the project soon but wanted your oppinions before i did all that. i have tryed everything else. new t stat, water pump, radiator, no leaks anywere externally except the overflow container.

any ideas???

PRO50SC

It should be able to hold 15 psi. Are there any external leaks? If it's leaking down, it's going somewhere.

vtecwho

i have looked all over and there are no external leaks. i just dont know where the bubbles would come from. when it bubbles it smells like it has a hint of exhaust smell to it.... thats what lead me to think the head gasket is allowing pressure on the compression stroke to excape.

AdderMk2

pull out all 8 spark plugs and pressurize the cooling system.

if the pressure drops, pump it up again. after a couple hours, kick over the engine with the plugs out and see if your cylinders turn into water guns!!!

if you find no leaks into your engine... you probably have a bad radiator cap

vtecwho

great idea. the radiator cap is new and has the stock 16lbs to it. its hard to start at times too, i dont know if that means anything but i NEVER has any starting issues before the cam.

the car is loosing quite a bit of water, if it were going to leak into the piston wouldnt it be smoking?

AdderMk2

not all the time... you can have a headgasket leak and not have steam

vtecwho

i have a radiator cap that lets you bleed the pressure before you take it off, is it normal for a lot of air to build up?? the overflow and coolant level stay constant untill i drive it briskly then look under the hood. its just frusterating.

AdderMk2

your actually NOT supposed to relieve the pressure in your cooling system. start up your car, part it facing up an incline and let it warm up. once it gets to operatiogn temperature. carefully release the pressure. then LEAVE THE CAP OFF overnight. Go back the next morning and see how low the fluid level is. top it off and put the cap back on... btw... I never recommend those pressure relase caps, they arent accurate.

i'd be willing to bet that you are having an evaporation problem IN the cooling system because of a poor burp job.


thats why I have one of these http://www.sjdiscounttools.com/lis22150.html

ZachW04Stang

The reason your coolant is boiling is because your overheating and boiling the coolant. Coolant will boil around 240-250*F. If you just did a cam swap more then likely the leak is either at the intake, thermostat, timing cover, or water pump.

If coolant ends up in the oil it doesn't mean that the head gasket is bad either, it could be timing cover or intake gasket as well.

vtecwho

ok, im doing what you suggested adder. would an air bubble or whatever it is you were discribing linger for a long time. i have put about 100 miles on the car since the cam swap. would the airbubble be out by then??