Have any of you had this happen to you, at idle the coolant flows throuhgt the radiator with no problem, but when i run the car on the track (track only car)and when i return to the pits i have lost my coolant in my radiator and its in the overflow. What do you think it can be. There is no coolant in the oil nor is it blowing out the radiator when i remove the cap.

 

The coolant expands as it heats up, it moves out into the reservoir. When it cools down, it's supposed to be sucked back into the radiator. (You knew that, right?)

If there's any air-leak in that hose going from the cap to the reservoir, then the radiator sucks air back instead of sucking coolant. (Ever try to drink thru a leaky straw?) Same thing if the top-most, largest rubber seal in the radiator cap leaks. Check the very top of the radiator neck for gouges that prevent an airtight seal up there.

 

Are you overheating?

 

i know it should suck back in but like i said i use it darag racing only, the raditator is brand new, it doesn't seem to be getting overheated. after a run the car is at like 180 -190 deg. i did notice the upper rad. hose is real tight. it check the engine with a heat gun and it reads the same thing as my electric gauage.

 

If its not overheating then I wouldnt worry about it. It could be your radiator cap is not holding the pressure causing the coolant to be forced into the overflow tank, but that would lead to overheating.

 

If it's not actually overheating, then I wouldn't worry about coolant moving to the reservoir. It's supposed to. I'd worry about why it's sucking air instead of coolant back in.

Since it's for racing only, it's not terribly inconvenient to check & fill it each time. In a daily driver, this is how you end up with a completely empty radiator...

 

I no its not to bad empying and refilling the radiator but its just not right, i was told that the head gasket was leaking between two of the ports one is a sucion and the other is blow or somthing like that but i have never heard of that.

 

I agree, it's not right. If you actually suspect a headgasket problem, I think you can get your coolant analyzed for combustion gases. Or maybe some kinda exhaust gas detector (sniffer?) at the radiator neck. Or even a leakdown test. But for a race-only car you've probably already done that stuff. You've already said there's no coolant/oil mixing & no continuous bubbling into the coolant.

But if it was my car I'd spend some time ruling out the simple thing of an air leak in the reservoir hose.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ALLMOTORD16Z6 &raquo;</TD></TR><TR><TD CLASS="quote"> i was told that the head gasket was leaking between two of the ports one is a sucion and the other is blow or somthing like that but i have never heard of that. </TD></TR></TABLE>I don't really understand that; it sounds kinda bogus.

 

I had the same problem on my car and it was the cap. It's not holding pressure like it's suppose too. Of course, i didn't have any leak at the headgasket either. Might want to change out the cap and see.

 

thanks for the info guys i'll the cap and recheck my hoses.