ok here is the deal i have an 02 lancer oz rally that i just put a motor in with 20,000 miles on it. everything works fine but the coolant issue, when i take the car out for a cruise and come home and park it i can hear the antifreeze boiling and it is being spit out of the radiator overflow bottle, the car DOES NOT over heat though. anyone know what is going on please help i cant figure it out.

 

Did you bleed the coolant system on the new motor? You might have some air pockets that are working their way out.

 

Hi,
I am the tech manager at Prestone coolants. Have you radiator cap tested mor just replace it with an OE mitsu cap. If your car is not overheating, doesnt have a leaking head gasket, the cap may be weak and lifting under pressure. A radiator cap and cooling system tester can be rented or borrowed from many retail auto parts stores, try and get one and test your system and cap. I looked up your car and there are no bleed screws on it, mitsu says fill the system, run untill heat comes from the hetaer, rev it to 3000 rpm a few times and shut it off and let cool. Remove cap and add to full line in resiviour.

 

no i havent tested the radiator cap i will have to do that this weekend, i recently used K Seal its a coolant additive that is supposed to fix damaged coolant components and it seems to not use nearly as much antifreeze as before, the thing is if it is leaking antifreeze somewhere i cannot find it, i just cant figure it out there is abosolutly no coolant in the oil, its not coming out the exhaust, and i have parked it on cardboard for the last month to see if it was dripping and nothing

 

if Im not mistaken there is indeed a bleed bolt on top of the thermostat housing right behind the lower rad hose , its sealed with a copper crush washer , loosen that bolt start the car and let it run til water trickles out tighten the bolt down, you have then successfully bled the system

 

you do realize water would sit at the bottom of the pan below the oil? the only way to verify is to drain the oil, water will come out 1st then the oil, just pulling the dipstick tube isnt good enough because of the design of the lower pan , the way to test that is to rent a carbon tester from an auto parts store , it locks onto where your radiator cap would go theres a dye in it that will change color if theres carbon in the coolant bubbles , meaning blown head gasket

 

My bet is 2$ on a head gasket.

 

i did not carbon test it no, but i have changed the oil a few times and the oil pan i bought is a clear one just for that purpose, if there was antifreeze in it i would be able to see it and not only that if antifreeze was in the oil it would raise the level on the dipstick, what im saying is that if there was a half a gallon in my oil it would show up somewhere and i did do this you can tell me if its wrong but i was told to take a small funnel and put it in the radiator cap hole, make sure its sealed and fill the funnel with antifreeze, if it bubble than the head gasket is bad letting the radiator fluid leak into the cylinders therfor going out the exhaust, idk if thats right but i did it and there were no bubbles????

 

I doubt that's a good way of testing a headgasket.
A leaky hg doesnt mean you'll have coolant in your oil. Coolant could be getting in the cylinder only when it circulates(car running) and gets burned in the combustion process. Does your exhaust smell funny?

Anyhow... I had the symptoms you described on a Honda and it was a bad headgasket.