My 2000 Honda Civic is losing antifreeze from the radiator. There is no change in the overflow reservoir level. No sign of antifreeze in the oil or transmission fluid and no sign of any foreign fluids in the overflow reservoir. I have not been able to find any fluid inside the car (heater core leak) and can’t find any puddles under the car…the stuff is just disappearing without a trace, like it’s being consumed in the combustion and going out the exhaust. It’s doing it fast too. A 15 mile trip can make 1 cup of antifreeze mix disappear out of the radiator only. Does anyone have any ideas where it’s going and how do I confirm and stop it?
There’s really only two ways to lose coolant: either a leak or it’s being burned (which is an internal leak, rather than an external one).
It’s technically possible for coolant to boil away, but you’d have to overheat the hell out of an engine for that to happen. Only seen it once, on a car whose thermostat was stuck closed.
Given the speed it’s being lost, I’d wager you’re leaking it out somewhere. It’s possible that you’re losing it only while going down the road where you won’t see it, and when you stop the engine, the leak stops as well. If you were burning the stuff at this rate, you would have tremendous billowing clouds of white smoke out of your tailpipe.
Did this start after any work was done on the car?
It may be the cooling system has air in it - as after a drain and refill. There is an air release spigot in Honda cooling systems, but not everyone uses it.
[b]Try replacing the radiator cap.
If the radiator cap doesn’t maintain the proper pressure of the cooling system, coolant can escape from the radiator as a vapor past the defective radiator cap. Also, if the cap is defective, coolant won’t tranfer from the coolant reservior to the radiator and back. And this might be why the coolant reservoir level never changes.
Tester[/b]
I’m having the same problem with transmission fluid. See magi transmission fluid. My advise to you is check for a leaky head gasket.
are you noticing any sticky filmy residue on the inside of the windshield?
how about a slight smell. (got any anti freeze at home? smell it to compare ((dont drink it)) coming from the vents?
are you checking the oil level? is it changing level, or changing color?
and most importantly as another suggested, have you had radiator, ac work done recently (six months or so)?
Lets see now
Transmission $2500
Head Gasket $1000
Radiator cap $9
I’d start with Testers advice, could be “Priceless”
Check the hoses, especially if you haven’t changed them in a coon’s age. Oftimes a hose can develop a pinhole leak on the underside rendering it undetectable to an above look. Additionally the fluid can leak to a point on the frame where it drains onto the ground at a point a distance from the engine bay. Furthermore if you’re checking the radiator level after a drive, you’re risking a steam burn when releasing the cap.
However I’m betting on a combination of a faulty radiator cap coupled with a small leak.
Check the hoses, especially if you haven’t changed them in a coon’s age. Oftimes a hose can develop a pinhole leak on the underside rendering it undetectable to an above look. Additionally the fluid can leak to a point on the frame where it drains onto the ground at a point a distance from the engine bay. Furthermore if you’re checking the radiator level after a drive, you’re risking a steam burn when releasing the cap.
However I’m betting on a combination of a faulty radiator cap coupled with a small leak.