Rep Power: 812

the last few times i opened the radiator cap, there was no pressure at all whether the coolant was hot or cold. it just opened. normally i would get a big spray of coolant everywhere and air hissing out. is this normal to happen? im not overheating and the cap is maybe 2 yrs old. oil looks good. overflow tank seems to be normal at the full line. i just changed the coolant yesterday and still not getting any pressure in the system. the cap seems to be tightening and sealing, cause there are no leaks. im having to add coolant to the overflow cause it keeps dropping a bit below max, but thats prolly from just changing the coolant.

 
Rep Power: 210

Off hand two possibilities come to mind. If there is no pressure when you remove the radiator cap either there is a leak in the cooling system so pressure bleeds off as it builds or you are not building up any pressure to begin with. My guess is you would notice a leak but if you have access you could pressure test the system to be sure. The other possibility is the thermostat is stuck open. If the thermostat is open and the outside temperature is not very high it would cause the coolant to circulate thru the radiator and never get hot enough to create pressure. I would test by checking the temperature of the upper radiator hose as the engine warms up. If the hose warms up slowly the termostat is open, if the hose goes from cold to hot quickly, that would be the thermostat opening. Another way to check the thermostat would be to watch the fluid in the radiator, if it is stuck open you should see the fluid flowing as soon as the engine starts.
That's all I can think of at the moment.

 
Rep Power: 812

i will check the hose thanks. i also have some air in the system thats not coming out but i dont think its that.

 
Rep Power: 0

You could also have a small leak in your [a href=http://www.radiatorsgalore.com]radiator[/url]. You can run a pressure check on your cooling system to find this out; you can pick up the equipment to do this at a local parts store. Some will loan it. Keep us posted.

 
Rep Power: 812

yeah thanks i need to do that anyways, but i dont think im leaking. altho i get to smell burning antifreeze for a while cause i spilled it all over during the drain and refill lol. but i think problem solved. after i bled the air out (there was a ton of it) for 5-6 times, the pressure seems to have come back. so i think everything is almost normal and i need to drive it around and work the other air bubbles out in a few weeks. i got most of it out tho.