Coolant leak

[Misfit3383]

I have a 1998 Explorer XLT V6, 4.0L AWD. It is leaking coolant, but I cannot see any signs of antifreeze. The antifreeze in my radiator is bright green, but the reserve tank is quite dirty, almost oily. I did put some stop leak in, but that was back in the winter. I have since had to put about 2 gallons of coolant in. Does anyone have any ideas?

 

[firepop5]

The coolant has to be going somewhere. If you can't see a leak, it's probably getting into the combustion chambers (cylinders). If it is a small leak it will be burned off and might be seen (white smoke) or smelled in the exhaust. If it is a larger leak, the antifreeze will mix with your oil and the oil on your dipstick will look frothy or brown as in your overflow bottle. If so you probably have head gasket issues. Needles to say, water in your oil is no good. Check you dipstick for evidence of water in the oil.

 

[DjDom]

Do you smell the antifreeze burning?
If it's burning, it will smell like Maple Syrup, very sweet.
Otherwise, try putting something under the car and making sure there's no leak.

 

[Misfit3383]

I have been under the vehicle many times, and can't find any evidence of a leak. I had it up on ramps and running for about 1/2 hour, with and without the throttle. I still can't find it. I checked the dipstick and the consistency of the oil seems to be normal. It seems to only leak when the heat is not running.

 

[Abbondanza]

Definitely the beginnings of head gasket failure, have it changed soon, or you will be on the side of the road when it completely fails.

Been through this and cracked a head because I waited too long.