94 Accord LX Mysterious Cooling System Issue
 

Hi All,

My 94 accord lx seems to be eating coolant. Here's the facts:
*Temperature gauge works fine, always in the middle
*Fans kick on when needed
*I have been checking daily, there are no puddles or leaks while parked
*No other fluid leaks
*The radiator is full
*No sediments in the tank
*No smoke or smells
*No puddles under the carpet (heater core symptoms)
*Oil smells and looks fine (seems like there isn't any coolant in the engine)

I cant figure this out. I have searched every forum and cant find anything...your help would be greatly appreciated.

Thanks!

How much, how often? Is the radiator getting low, is the overflow tank getting low, or both?

I filled the overflow tank (which was empty). It has now been 750 miles and it is empty. I filled it back up and I am going to be keeping an eye on it to see how it uses it. There is no leaking now I just checked it. The radiator is full.

OK, so a quart every 500 miles or so? Did you check the steel coolant pipe behind the engine, and all of the hoses that connect to it? With such a small amount of coolant disappearing, it could be that a tiny leak there (or anywhere) could be evaporating before it has time to hit the ground. If you don't have one, rent a cooling system pressure checker from an O'Reilly or some other auto parts store, pump it up to 15 lbs., and go over every hose and connection.

If it's definitely not leaking externally then it's leaking internally. A small head gasket leak could allow just a bit of coolant into the cylinder(s) where it gets burned. Since it's such a small amount, you wouldn't notice any white smoke, or coolant in the oil (or vice versa.) Does the car run rough for a second or two after sitting overnight?

That sounds about right...and that makes sense since none of it hits the ground. The only reason I dont think its the head gasket is because the engine looks almost spotless as far as any leaking is concerned. Not to mention, I don't see any indication of coolant in the oil or engine. I'm hoping I only need a hose or something fixed, cause I really don't want to dump $1000 to get the head gasket repaired :(

Most parts stores will rent a radiator pressure tester. You can see if the radiator is holding pressure. You can also inspect the hose(s) going from the radiator to the overflow tank for signs of leakage.

With the tester, also look around the front side (belt end) of the engine. A slow weep from the water pump might be the source.....the are some inexpensive uv dye kits you could look into.

ahh thanks everyone. i checked it after driving about 50 miles and it doesnt seem to be losing any yet. i guess we will have to wait and see.