2006 4.0L v6 Explorer is leaking coolant but can't locate?

[RPFLimited]

So through the grace of this awesome site, I thought I had this figured out but frankly, Im just not sure now.

My truck has been losing coolant out of nowhere now, and I couldnt figure out just where in the hell it has been going. I heard some water noise behind my dashboard, and I concluded must be the heater core.

Today I decided to crawl around while the car was running and see if I could locate the leak. I think I did. While the car is running, fluid is just leaking at a rapid pace right above the catalytic converter, dripping down on the automatic transmission... Sure enough I took - there's some rust looking color only on that side, not on the other. Water has clearly been dripping into this for a while now.

My question is - where could this leak be coming from? I can't seem to locate it by look alone, and obviously it only leaks when the truck is running so I cant reach up and feel around - I'll burn my hand off.

Any ideas? Does this CONFIRM the heater core being bad or is this simply another source of the leak?

Thanks again - this site is great. Its kept my truck on the road and sadly right now I cant afford to get something new so I need this for another 6 months or so

 

[Tech By Trade]

Thermostat housing into the valley and back down the transmission. Doorman will run ya around 30 bucks.

 

[RPFLimited]

I should have also said -

I replaced the water pump, thermostat and intake. No sign of leaking at all until very recently. Possible my housing just went bad?

 

[Tech By Trade]

If you never replaced the housing its self it is almost a guarantee.

 

[RPFLimited]

Sadly I did. When that started leaking it was very obvious and the back cracked bc it was cheap plastic.

It's leaking behind the engine somewhere. I just can't pinpoint it.

 

[RPFLimited]

Is it at all possible this is still my heater core going bad and leaking?

Would a heater core bypass work? I'm in florida now and never ever use the heater. Plus I'm likely selling this car in a few months.

Next I have to tackle the damn swaybar bushings going bad :-/. Never ends

 

[Old As Dirt]

Check the "O" ring around the computer temperature sensor located in the top of the thermostat housing. There is a clip (retainer) holding the sensor in place. Carefully (holding the clip with needle nose pliers) pull the clip and remove the sensor. I replaced mine and the leaking stopped. I flipped the retainer in the process and that is the reason I emphasize that. Total cost of the retainer and the "O" ring at the Ford dealership = $12. If you don't lose the clip, a cheap purchase at the hardware store. After doing this, wash all the coolant from under the throttle assembly area. The water will evaporate. The sound in your heater core is probably air from your losing coolant.

 

[RPFLimited]

Thanks man I'll check tomorrow!

 

[Flag Gibby]

If coolant is coming out of the HVAC condensate drain under the vehicle then yes, it is possible that you have a pinhole leak in the heater core, but it has to be coming out of the drain tube and not just running down the firewall from somewhere else. However, I would think that if you had a leak in your heater core you would smell it in the cab anytime you had the blower on. I would be looking under the hood for the leak since you don't indicate smelling coolant in the cab.

 

[03explorereb]

If coolant is coming out of the HVAC condensate drain under the vehicle then yes, it is possible that you have a pinhole leak in the heater core, but it has to be coming out of the drain tube and not just running down the firewall from somewhere else. However, I would think that if you had a leak in your heater core you would smell it in the cab anytime you had the blower on. I would be looking under the hood for the leak since you don't indicate smelling coolant in the cab.

what he said x2.
also be looking at the heater control valve which resides on the passenger side of the engine. has a vacuum line going to it. this piece of junk almost cost me an engine on two different occasions. in addition to the heater control valve there is a T junction on the same side that are known to leak. beyond the above and previous mentioned, radiators are the next biggest problem area with leakage. looking under the radiator you can usually see a small amount of coolant pooling on the bottom side of the mount pads. just my .02 cents.

 

[RPFLimited]

I haven't run the heater until recently but now I'm smelling coolant.

Going to try the thermostat housing thing mentioned above. I'll update. Thanks guys

Can I bypass this heater core? I'm in south florida and never run the heater. I'm trading car in relatoverly soon.

 

[RPFLimited]

Yeah, everything looks fine there. Gotta be the heater core. Can I by-pass it or no?

 

[Flag Gibby]

Yes you can. You could also try the yellow mustard trick or add stop leak to the radiator to see if that plugs up the leak instead of spending the money on some connectors and tubing to bypass the heater core. Honestly, before you do either one I would find the condensate drain on the firewall and verify that there is coolant coming out of it.

 

[03explorereb]

If you don't want to modify the hoses, which I wouldn't, I would buy a brass fitting that has a double barb (one on each end), connect each end coming from the heater core and run it as a loop. You could plug each end as well(?)

 

[Flag Gibby]

Very similar to my thougths, 2-90's and a small piece of hose to connect the two 90's where they connect to the heater core and I wouldn't bother with the heater core ends. Of course, this is all after verifying that the leak is at the heater core.

 

[RPFLimited]

Is there a diagram somewhere or pictures to help me locate the condensate drain? You guys are awesome, thanks so much

 

[Flag Gibby]

See here: http://www.explorerforum.com/forums/showthread.php?t=211350

 

[RPFLimited]

Fantastic. When replscing my swaybar links this weekend I'll take a look.

Is there a way to donate to this site? Over the past 3 years you guys have been invaluable in servicing and fixing my explorer likely saving me hundreds of dollars

 

[MotorCityFats13]

looks like you do that by becoming an elite explorer .... but I like an option on choosing the amount and getting no frills ...... I cant ever get lucky with problems seams like mine are always really advanced and never get reply's... I joined this site because I just bought a 2007 xlt because my 1998 just **** out and not 1 month after signing for it the cluster took a **** and was hoping I was missing a hidden fuse before taking it in and seeing what this service contract I payed $1200 for is good for... I never had luck with any warranty programs so I cant see a service contract working for me.... worst one was the factory warranty on my 2004 cobra I bought new... ford said I was too young for that kind of car and voided it when the rear diff cover snapped....

 

[RPFLimited]

I owned a 360r roush then an 03 cobra then an 06 Gt500 (