Coolant Leak - Passenger side

[ftexplorer]

I have a 2000 Ford Explorer XLT 4x4. Recently, the coolant has started leaking on the passenger side near the firewall. I checked the oil for coolant, and it doesn't look like it exists. I can most likely say it is not a head gasket. It looks like the leak is coming from underneath the evaporator core (the thing that looks like it is wrapped in aluminum foil). I looked underneath the car and can verify this. Also, the the wheel well piece that is held by plastic plugs is wet on the left most plug. So the leak is definitely coming from behind the wheel well. It only leaks after the car is started and has had a chance to pressurize the cooling system. My next step is to get the wheel well off completely to look and see. I've read about others replacing their heater control valve and fixing the problem. I don't have a heater control valve that I can see, so it might not be on the 2000's. Does anyone know what radiator hose/tube is located where I am describing, which is under the evaporator core and behind the wheel well?

 

[ericg75]

This is a very accurate description of the problem I'm currently having. Coolant dripping from the bottom of the evaporator core right near the firewall(crawled undeneath and verified). However the two hoses directly above the evaporator are dry. So where is my leak coming from??? I cannot see any heater control valve on my 99 either.

 

[BornintoFord]

Could be the Heater Control Valve that the 2 hoses go to. My 96 Explorer had a slight drip as well and turned out to be the clamp need to be adjusted.

 

[ericg75]

I can't seem to locate the heater control valve but what I'm thinking (and dreading) is that it's the heater core. The floor is not wet however I bet if I turn on the defroster it's not going to make any heat or it will reak of coolant. I'll check on it tonight .

 

[11623david]

I have same issue, did you figure it out?

 

[Turdle]

Sounds like a heater core leak to me.

Wish I had better news for you.

 

[Groundjet Pilot]

Hi Guys,

Reviving this old thread I just came across while having the same problem discribed above.

In all my research a likely fix might be to clear the A/c Drain plug near the heatercore inlet/outlet hoses at the firewall.

I have seen other threads that say this drain hole cloggs up so you need to clear it by sucking it out with a wet dry vac or sticking something into the hole to clear the stoppage.

I'll do mine tonight and follow up so anyone after me will have another option to try.

 

[1998Exp]

Indeed, it's a good idea to clear the drain. Unfortunately, the only substance that's supposed to flow out of there is clear water - the result of dehumidifying the inside your vehicle. If you see green, sticky substance, the heater core is shot. Another sign of a leaking heater core is an oily film on the inside surface of the windshield. Good luck!

Hi Guys,
...
In all my research a likely fix might be to clear the A/c Drain plug near the heatercore inlet/outlet hoses at the firewall.

I have seen other threads that say this drain hole cloggs up so you need to clear it by sucking it out with a wet dry vac or sticking something into the hole to clear the stoppage.
...

 

[Groundjet Pilot]

Didn't work and the leak is coolant, so I will try one other option before pulling the core ..change the thermostat and pray!

 

[1998Exp]

No offense, but if changing the thermostat cures your heater core leak, you are experiencing a miracle.
Heater core replacement is not a fun job, but I have seen worse. Good luck, brother!

Didn't work and the leak is coolant, so I will try one other option before pulling the core ..change the thermostat and pray!

 

[Groundjet Pilot]

Lol I know, I plan to flush the entire system, replace the thermostat, and see if I still leak coolant, it's only loosing about 8 to 10 oz intermittently, if that doesn't fix it the I will pull and replace the heater core this weekend. It's my wife's truck she drives about 7 miles round trip to work so the truck barely has time to warm up. My bigger issue is rebuilding the turbo on our #3 car (2002 Saab 9-3). Oh the joys of the DIY mechanic!

 

[Groundjet Pilot]

BTW I have pretty warm heat, no moisture on the windshield, no moisture on the interior floor, just the intermittent coolant loss at the firewall, and the upper radiator hose has no fluid flowing through it....compound issue? Air in the system? I'm not sure but I'm hoping a thorough flush fill and new thermostat will expose this problem... thanks for replying any other thoughts are appreciated. Cheers!

 

[DoraExploder]

Hello, I'm having this problem as well. It started after having my coolant flushed, so chances of that being a fix are nil.

I'm not having any heat issues--no fogginess, no lack of heat, no smells...

And my coolant doesn't seem to be going anywhere, either...

I'm confused. It only leaks occasionally, too. No puddle today, but there was one on Friday. Any solutions?

 

[lorraine1]

mine started out this way ,then eventually started fogging the windshield in the dead of winter,finally changed the heater core.