Coolant Leak from Undercarriage

[mranderson214]

Hello Everyone,

Lately I've been having an issue with coolant leaking and I'm sure someone on this forum probably had the same or similar problem. Thanks for your time!

I have a 2002 Explorer XLT, V6 with about 185,250 miles on it.

Problem:
Basically the issue seems to be that I'm leaking coolant, not a lot but a few drips here and there. The location seems to be directly behind the front wheels closer to the drivers side wheel. Besides the leak, I'm noticing no decrease in engine performance or MPG. No check-engine lights etc after months of this happening.

Background:
Originally my mechanic thought that it might've been oil leaking caused by a bad head gasket or a bad valve cover gasket. After monitoring my oil for months, I realize I'm not losing oil. After smelling the fluid, it seems to be antifreeze/coolant that I'm leaking.

My Thoughts:
I don't believe that it's a head gasket because I don't have any of the symptoms of head gasket failure. I'm convinced that it might be the lower thermostat housing because it looks a little moist around the base of the lower thermostat housing. My confusion comes from the fact that the lower thermostat hoiusing is closer to the front of the vehicle, whereas the leak I'm noticing is right behind the driver's front tire. I thought it would be possible for the housing to leak and the fan might blow it back a little however, the leak still happens in the same place if the car is running or not.

My Question:
I know that I am definitely losing coolant. Does this sound like the lower thermostat housing is the culprit? I confused because the location of the housing and the location of the drops don't add up. Is it possible that coolant would drip down from the housing to the location I mentioned above? Lastly, if it's not (just) the housing, what do you guys think it might be?

In the mean time, I keep 2 bottles of coolant in the trunk and check it religiously in order to make sure the coolant doesn't get too low.

Thanks in advance, and I'm sorry for the length. I just wanted to be as detailed as possible.

Thanks,

 

[mranderson214]

Problem Solved!

Just updating for anyone that may have a mysterious coolant leak. I went roughly 3000 miles since I first noticed the problem and hadnt had a check engine light or noticed any decline in performance.

The problem was the infamous lower thermostat housing. It ended up being the case that the coolant would leak from the back of the housing and seep through towards the back of the engine where it'd ultimately fall to the ground around the back of the front set of tires.

The confusing part was the location of the drops on the ground with respect to the actual housing itself. As many have mentioned, the housing on this model is made of plastic and much like everyone else's I've read about; the housing was warped on the bottom back-side.

Hopefully this helps someone.

 

[D Hook]

Thanks for following up with your findings. Water (coolant) can be insidious and difficult to find the original leak because of the tricky paths it takes before dripping. Glad you caught it before something bad happened that left you stranded.

 

[AeroRamer]

That was a problem with my 2000 Ex. I kept driving it and pouring more coolant in it until the cover catastrophically broke. It was a fountain water show. LOL.

 

[mranderson214]

Exactly! Finding this took months because at first we thought it was oil but was able to narrow things down when we realized it was antifreeze. It's all a learning process I guess. I was worried it was something more serious but after getting my housing swapped out, I'm relieved and so far so good. No leaks.

On another note, I now have 2 extra full containers of coolant haha