Hey guys.........I'm stuck. It seems that my overflow tank is filled with coolant, and it even overflows sometimes when I'm driving(can see the spots on my intake tube). But here's the thing, there isn't too much fluid in the system. Even after letting it sit for a day I go and check it and the overflow is full and I go to take the radiator cap off, it's like opening a bottle of Mountain Dew, pressurized, and no coolant, it's all in the overflow. I'm thinking its the thermostat, because I am fairly sure it's not the headgasket(recently replaced it). Car is a 2000 Civic Si with jackson blower modded by endyn. Thanks for the help.
-Blake

 

Any ideas??

 

It's even possible for a bad radiator cap to do that. The cap controls how the coolant gets sucked back into the radiator as it cools down. Check that ALL the seals & springs in the cap are ok. Make sure the hose from the cap to the reservoir is OK without any leaks.

Otherwise if it keeps overflowing the reservoir, it could be a bad headgasket.

 

could be head gasket, thats what mine did when it blew. The coolant would get blown into the overflow and then blown outta there. Just pop off your radiator cap, start your engine, looking at the radiator rev your car a little for like a minute or two, not too high or you will wear it, and see if your coolant bubbles, if it bubbles, your head gasket is bad.

 

Thanks guys

 

if the coolant is milky oily, it's the HG

 

It's definatly not milkey, and there is no coolant in the oil. That is why I am stumped. I am really leaning toward the thermostat. I'm so confused.

 

u could have a busted radiator...it happend to me changed it and fixed everything