Wits End - Coolant Leak

[il66pony]

At this point, I am not sure of anything except the sun which did rise in the east again today. When I first spotted the "liquid" on the floor two weeks ago, it was definitely antifreeze. Tasted so sweet that I do not think any appreciable water was mixed in. Also, I do think you are right about the compressor running at times due to humidity in the cabin. Yesterday when I was running around getting estimates, I did not use the heater. It was fairly warm a quite humid. It also was raining on the way home. Obviously, a lot of water was dripping off the car. This morning, the floor is as dry as can be.

I have thought of another thing that I question. When installed, the core sits flat at the bottom and the tubes rise above it and exit near the top of the firewall. So that means, there is always coolant in the core even with the heat turned off. With the heat turned off, if just sits there and of course it is not circulating. Also, no pressure. So, it would seem to me that a large leak would drip out all the time even when the car is parked overnight.. So, if I am right about this, it seems like if I have a leak, it is small and only leaks under pressure. I suppose it is possible that I had a leak and gunk in the cooling system plugged it up and it is okay for now.

I will be on the road with the car for about two hours today and the temp will be in the upper sixties. So, I will run the heater some and see what drips and analyze quickly before whatever would have a chance to dry up. I will also really try to see if I can smell coolant with the heat on.

I will hold off using any kind of stop leak magic for now.

That is this morning's update.

Dave
View attachment 342694

 

[il66pony]

At this point, I am not sure of anything except the sun which did rise in the east again today. When I first spotted the "liquid" on the floor two weeks ago, it was definitely antifreeze. Tasted so sweet that I do not think any appreciable water was mixed in. Also, I do think you are right about the compressor running at times due to humidity in the cabin. Yesterday when I was running around getting estimates, I did not use the heater. It was fairly warm a quite humid. It also was raining on the way home. Obviously, a lot of water was dripping off the car. This morning, the floor is as dry as can be.

I have thought of another thing that I question. When installed, the core sits flat at the bottom and the tubes rise above it and exit near the top of the firewall. So that means, there is always coolant in the core even with the heat turned off. With the heat turned off, if just sits there and of course it is not circulating. Also, no pressure. So, it would seem to me that a large leak would drip out all the time even when the car is parked overnight.. So, if I am right about this, it seems like if I have a leak, it is small and only leaks under pressure. I suppose it is possible that I had a leak and gunk in the cooling system plugged it up and it is okay for now.

I will be on the road with the car for about two hours today and the temp will be in the upper sixties. So, I will run the heater some and see what drips and analyze quickly before whatever would have a chance to dry up. I will also really try to see if I can smell coolant with the heat on.

I will hold off using any kind of stop leak magic for now.

That is this mornings update.

Dave

 

[Bazz270]

Usually

All the coolant system are fully pressurized (coolant pump work pressure 20psi) except of max a/c (air circulating inside the car only) turned on and as a result heater valve closed.

 

[il66pony]

Usually

All the coolant system are fully pressurized (coolant pump work pressure 20psi) except of max a/c (air circulating inside the car only) turned on and as a result heater valve closed.

Not sure I understand. Are you saying that with the heater valve closed on the one hose, the core is still being pressurized by the other hose. If so, I had not thought of this. But, if I am reading this right, you are saying that the core is always pressurized with regular AC on but not when MAX AC is on? If so, what in the system changes to release the pressure from the core?

 

[Bazz270]

Exactly.

You can read it in workshop manual (aircon and cooling system sections)
All of the cooling components are fully pressurized all the time ( of coarse after engine termostat opened - radiator bypass situation) except of closed Y-pipe heater bypass valve situation(operated via vacuum lines with manual or automatic controls)

After bypass closed,heater core keeps 20 psi and constant liquid volume inside since outlet heater pipe stay pressurized as well (kind of pressure vessel )

cooling liquid wont circulate until a/c max button depressed.

In other words,
When you turn your a/c max on
bypass valve decreases heat energy exposed to the closed airflow blend door but system still stays pressurized with liquid inside.

 

[MNgopher]

I've read through most of the posts.

Are you sure its coolant leaking? Are you actually loosing coolant in quantities large enough to notice? (When the Y pipe leaked on mine, it would take a month before the coolant level changed enough to really notice in the overflow - but it was definitely leaking).

Have you done a coolant pressure test? Here at least you can usually borrow a tester from an auto parts store, connect it up and find the leak with nothing running. Seems like you are trying to find it with everything running... I've had great success tracking leaks this way on other vehicles. If the pressure drops - either the tester fitting is leaking, or its going elsewhere and you can and will find it...

Recognize that the AC can put out huge volumes of condensate water when running in the right conditions. Humid weather and our would leave puddles everywhere from the front and rear A/C. Strong possibility your taste was from whatever else the condensate ran over.

And as was pointed out, the A/C will run with defroster on unless its too cold, regardless of the other settings.

If you decide to sell, we have a 21 Explorer that we love. The only thing I miss is the sound of the V8. It does everything else we ask of it and does it better.

 

[Bgreenwale]

2007 Mountaineer 4.6 V8, rear heating and AC, 103k miles. A couple of weeks ago, I noticed coolant dripping from a bolt on the bottom of the passenger side frame rail. It was dripping (not much) about 18 inches back of the rear edge of the front fender. I looked but could find no obvious leak so I came here and posted about it. Seems like the culprit would be the "Y" hose assembly that runs to the right side of the exhaust manifold and down for the rear heater. So I got the part yesterday, took off the air intake assembly, wheel, and a rubber flap in the wheel well. Everything was dry as a bone with no sign of any kind of leak. And of course antifreeze does not evaporate. So, traced the heat and AC lines all the way back to where they enter the cabin in the rear. Everything dry as a bone. Side of engine, rear of engine, bell housing, tranny not a single trace of coolant. BTW, when I first noticed this the overflow tank was empty when cold. I did put some in to get a little in the tank.

So, while driving it in the last couple of weeks, coming home and parking it, it has leaked several times but not every time. It has been pretty hot here so only the AC has been on. Have not driven it at night during all of this so no chance the heater kicked on. Today is cooler so I may take it out tonight and run bot front and rear heat and see what happens.

Has anyone ever had an elusive leak like this? Any ideas for me?

Again, thanks in advance.

Dave

Get a coolant pressure tester and pump the pressure up to at least 10 lbs.

 

[Roboro1972]

2007 Mountaineer 4.6 V8, rear heating and AC, 103k miles. A couple of weeks ago, I noticed coolant dripping from a bolt on the bottom of the passenger side frame rail. It was dripping (not much) about 18 inches back of the rear edge of the front fender. I looked but could find no obvious leak so I came here and posted about it. Seems like the culprit would be the "Y" hose assembly that runs to the right side of the exhaust manifold and down for the rear heater. So I got the part yesterday, took off the air intake assembly, wheel, and a rubber flap in the wheel well. Everything was dry as a bone with no sign of any kind of leak. And of course antifreeze does not evaporate. So, traced the heat and AC lines all the way back to where they enter the cabin in the rear. Everything dry as a bone. Side of engine, rear of engine, bell housing, tranny not a single trace of coolant. BTW, when I first noticed this the overflow tank was empty when cold. I did put some in to get a little in the tank.

So, while driving it in the last couple of weeks, coming home and parking it, it has leaked several times but not every time. It has been pretty hot here so only the AC has been on. Have not driven it at night during all of this so no chance the heater kicked on. Today is cooler so I may take it out tonight and run bot front and rear heat and see what happens.

Has anyone ever had an elusive leak like this? Any ideas for me?

Again, thanks in advance.

Dave

I own a 2006 mountaineer 4.6 premier & i had same problem. I replaced the small crossover lines in back by firewall & everything. It ended up being that "Y" piece you speak of. As it gets hotter, the plastic will develop a hairline crack i found. The real Ford Part costed me about $200, but some parts i will only trust OEM due to quality. FOMOCO parts have a 2 year warranty on them. But yes, I could bet that its a hairline crack in the valve. The reason the FoMoCo part is so much is its all fully assembled, just remove hoses from yours & new one has clamps & hoses ready to rock & roll. I love my Merc & havent had a problem since...

 

[C5Mike]

Two years ago my 2008 4.6L Explorer Limited developed a leak with the same location and symptoms you mention. I could smell it inside, it was on the passenger side, and only leaked when hot. I traced the leak to the aluminum heater piping junction on the firewall as shown in the attached photo. The weld had a crack in it. I cleaned the pipes and applied J-B Weld WaterWeld generously. It hasn't leaked since. Simple and cheap, $5 on Amazon. Besides fixing the leak, it greatly increased the strength of the joint.

 

[Bazz270]

Firewall piping hoses are a part of Y-Pipe ford assembly

So if replaced they should be all new.

 

[MeyerVW]

2007 Mountaineer 4.6 V8, rear heating and AC, 103k miles. A couple of weeks ago, I noticed coolant dripping from a bolt on the bottom of the passenger side frame rail. It was dripping (not much) about 18 inches back of the rear edge of the front fender. I looked but could find no obvious leak so I came here and posted about it. Seems like the culprit would be the "Y" hose assembly that runs to the right side of the exhaust manifold and down for the rear heater. So I got the part yesterday, took off the air intake assembly, wheel, and a rubber flap in the wheel well. Everything was dry as a bone with no sign of any kind of leak. And of course antifreeze does not evaporate. So, traced the heat and AC lines all the way back to where they enter the cabin in the rear. Everything dry as a bone. Side of engine, rear of engine, bell housing, tranny not a single trace of coolant. BTW, when I first noticed this the overflow tank was empty when cold. I did put some in to get a little in the tank.

So, while driving it in the last couple of weeks, coming home and parking it, it has leaked several times but not every time. It has been pretty hot here so only the AC has been on. Have not driven it at night during all of this so no chance the heater kicked on. Today is cooler so I may take it out tonight and run bot front and rear heat and see what happens.

Has anyone ever had an elusive leak like this? Any ideas for me?

Again, thanks in advance.

Dave

Sounds like the heat core is leaking. Look for the ac drain hose and see if coolant is coming out of that.

 

[il66pony]

Two years ago my 2008 4.6L Explorer Limited developed a leak with the same location and symptoms you mention. I could smell it inside, it was on the passenger side, and only leaked when hot. I traced the leak to the aluminum heater piping junction on the firewall as shown in the attached photo. The weld had a crack in it. I cleaned the pipes and applied J-B Weld WaterWeld generously. It hasn't leaked since. Simple and cheap, $5 on Amazon. Besides fixing the leak, it greatly increased the strength of the joint.

Ding, Ding Ding! You are a genius. I just got home from my travels today. Had the heat on, then the AC on and back and forth. Then for the last 15 minutes had the system off. So, I just went out and found coolant on the underside of that pipe right by the weld. Thank you, thank you thank you! The y pipe is still completely dry. I guess I missed feeling the underside of that pipe because hey, a metal pipe won't leak! I did not see the weld. I was so excited that I did not even look to see if that is a replaceable part. I think I would rather replace it than try the JB Weld. Was there anything you did special with the JB weld? I assume you do it with the car stone cold. Did you clean and shine up the pipe with steel wool or very fine grit sandpaper?

Again, thank you so much for taking the time to find, read and reply to the the thread. The picture was perfect!

And thanks to all who weighed in on this thread over the past five days!

Dave

 

[il66pony]

A couple of other things to add. Early on in the saga I took it to a local Ford Dealer for a diagnostic fee of $100. They did pressurize the system. They found some dampness on the radiator by the lower hose. Not dripping. It had never dripped before from up front so I dismissed that. I had told the service manager that I thought it could be the Y pipe as that that seemed to be a common problem I found out about here on the forum. The tech did not check that. So they re-pressurized the system and came back with a qoute on fixing that - $550. Did not say they found that leaking. I just assume they did because because of the quote. Along with $600 for a new radiator. The one good thing (I think) was that they checked my lower ball joints as an independent shop I took it to for an oil change told me they were loose. Not sure why they checked them. Anyway, the tech said they were fine.

So, I have been looking at KIA Telurides and Hyundai Palisades. Best I could find was $5,000 over MSRP on a Teluride and a six month wait. Best on a Palisade was $3,000 over MSRP and a 2-4 month wait. But last night I found a Teluride in the right color scheme on a dealers lot 25 miles away. I went over today. $13,000 over MSRP. Non negotiable. In my state that would also add another $1,000 in sales tax. That was a real short conversation.

If Ford still offered V6 non turbos in Explorers, I would consider it. Service manager at the Mercury dealer confirmed what I thought. The turbos will break those engines long before their time. As he put it, they are fun until they break. Then it ain't fun.

 

[Explorerpr]

2007 Mountaineer 4.6 V8, rear heating and AC, 103k miles. A couple of weeks ago, I noticed coolant dripping from a bolt on the bottom of the passenger side frame rail. It was dripping (not much) about 18 inches back of the rear edge of the front fender. I looked but could find no obvious leak so I came here and posted about it. Seems like the culprit would be the "Y" hose assembly that runs to the right side of the exhaust manifold and down for the rear heater. So I got the part yesterday, took off the air intake assembly, wheel, and a rubber flap in the wheel well. Everything was dry as a bone with no sign of any kind of leak. And of course antifreeze does not evaporate. So, traced the heat and AC lines all the way back to where they enter the cabin in the rear. Everything dry as a bone. Side of engine, rear of engine, bell housing, tranny not a single trace of coolant. BTW, when I first noticed this the overflow tank was empty when cold. I did put some in to get a little in the tank.

So, while driving it in the last couple of weeks, coming home and parking it, it has leaked several times but not every time. It has been pretty hot here so only the AC has been on. Have not driven it at night during all of this so no chance the heater kicked on. Today is cooler so I may take it out tonight and run bot front and rear heat and see what happens.

Has anyone ever had an elusive leak like this? Any ideas for me?

Again, thanks in advance.

Dave

Pressure test it. Get a radiator presdire test kit maybe at autozone etc, they provide it for free for a week or more. And apply the same pressure the radiator cap had labeled, 12psi etc. Give an hour pressurized and Then you can trace the drip. With that kit also maybe you can test the radiator cap too.

 

[D Hook]

If Ford still offered V6 non turbos in Explorers, I would consider it. Service manager at the Mercury dealer confirmed what I thought. The turbos will break those engines long before their time. As he put it, they are fun until they break. Then it ain't fun.

Exactly! That and the chain driven water pump that I've read about is what keeps me away from the newer Explorers. Love to have one but not with those two "features". I like to keep my vehicles for a long time and those two items are troublesome to me.

Glad you found the leak!

 

[C5Mike]

I'm glad to have been able to help. I used a Scotchbrite pad and water to clean it. The WaterWeld is an epoxy putty that is easy to apply. You just cut off a chunk, knead it and apply it. It cures in an hour and will set up underwater. The engine was completely cold so the joint was not leaking. I figure my fix is better than new since I built up the connection to stabilize it. The design of the part is faulty, being too weak so a new one could do the same thing. If my fix ever fails I might replace the part if it is still available. I don't think it will fail.

 

[MNgopher]

So if I've read it right, your dealer did do a pressure test, pointed at the radiator, and then said that's it. The OP mentioned the Y pipe, and they rechecked and offered to replace the part for $550.

In the dealer's defense, the Ford part contains the metal piece in question, and would have solved the issue. MSRP is around $300 for the whole thing (lots of hoses and metal parts...), plus labor and antifreeze... The OP declined and never really clarified if the dealer actually found the leak or not. The JB weld fix may work, but is not how a dealer is typically going to do things...

The 2.3 Ecoboost in my '21 has a belt driven external waterpump. The chain driven ones were typically found in transverse mounted 3.5 units, pre 2020 models. The current gen explorer went back to RWD, so the engines are placed like truck engines again (which also don't have chain driven water pumps).

I could reminisce about the '07 Explorer I had or call out the flaws in it... I'd state it had more than its fair share of problems - warped exhaust manifolds (both sides done, and had started breaking studs again), spark plugs that fused themselves in, the 3V modular VCT issues, etc..., ate wheel bearings like they were going out of style... to start the list... among many, many more issues. We're happy with our '21 - it gets nearly 8 mpg better gas mileage in the same use, and meets all of our needs.

 

[94Eddie]

I could reminisce about the '07 Explorer I had or call out the flaws in it... I'd state it had more than its fair share of problems - warped exhaust manifolds (both sides done, and had started breaking studs again), spark plugs that fused themselves in, the 3V modular VCT issues, etc..., ate wheel bearings like they were going out of style... to start the list... among many, many more issues. We're happy with our '21 - it gets nearly 8 mpg better gas mileage in the same use, and meets all of our needs.

Every generation of Explorers/Mountaineers etc. have their issues. I am sure the 6th gens will be no different. Give it time and their will be plenty of turbo failures on the Ecoboost engines around the 100k mark that hopefully won't take out the engine. Many new vehicles, including the 6th gen Explorers and variants, are going to be hella expensive to repair when they are out of warranty.

 

[il66pony]

I'm glad to have been able to help. I used a Scotchbrite pad and water to clean it. The WaterWeld is an epoxy putty that is easy to apply. You just cut off a chunk, knead it and apply it. It cures in an hour and will set up underwater. The engine was completely cold so the joint was not leaking. I figure my fix is better than new since I built up the connection to stabilize it. The design of the part is faulty, being too weak so a new one could do the same thing. If my fix ever fails I might replace the part if it is still available. I don't think it will fail.

Scotchbright pad. Good idea and I have some. JB weld will be here later today. I am thinking you applied several layers to build up the strength of the pipe where the weld is. Sounds like you waited an hour between layers. I did find the part. It is most of the under hood heater plumbing including the "Y" piping. It also has the shut off valve. It is Motorcraft. Here is a link to it.

2006-2010 Ford Hose Assembly - Coolant Inlet 6L2Z-18C553-C | Group 1 Auto Parts

Not too bad at $180.00 So, I will try the JB Weld. If it does not work, I will then get the part. Then I will take it to have the cooling system flushed as it has never been done and I am at 103,000 miles. Probably do the transfer case as well.

I am really glad I did not feel that I needed to try the Bar's Liquid Aluminum. I am taking it back to O'Rielly's today!

 

[il66pony]

So if I've read it right, your dealer did do a pressure test, pointed at the radiator, and then said that's it. The OP mentioned the Y pipe, and they rechecked and offered to replace the part for $550.

In the dealer's defense, the Ford part contains the metal piece in question, and would have solved the issue. MSRP is around $300 for the whole thing (lots of hoses and metal parts...), plus labor and antifreeze... The OP declined and never really clarified if the dealer actually found the leak or not. The JB weld fix may work, but is not how a dealer is typically going to do things...

The 2.3 Ecoboost in my '21 has a belt driven external waterpump. The chain driven ones were typically found in transverse mounted 3.5 units, pre 2020 models. The current gen explorer went back to RWD, so the engines are placed like truck engines again (which also don't have chain driven water pumps).

I could reminisce about the '07 Explorer I had or call out the flaws in it... I'd state it had more than its fair share of problems - warped exhaust manifolds (both sides done, and had started breaking studs again), spark plugs that fused themselves in, the 3V modular VCT issues, etc..., ate wheel bearings like they were going out of style... to start the list... among many, many more issues. We're happy with our '21 - it gets nearly 8 mpg better gas mileage in the same use, and meets all of our needs.

The less expensive piece with the Y is sold with just the Y and hoses. It does not include the other stuff that comes with the part listed above. But no matter. I am not dissing the dealer. Heck, it took me and all the great folks on this forum over two weeks to track down this leak.

I guess I have been lucky with my 2007 Mountaineer. At 7,000 miles, the right front tire rubbed through the brake hose so I lost front brakes. At 50,000 miles, the front passenger seat movement ate through the seat wiring harness which caused the air bag warning light to come on. That cost $250. At 80,000 miles I paid $500 to have the dealer replace the spark plugs using their process to ensure the old plugs did not break off. At 90,000, I did the brakes. That's it until this leak.

I love this car. New cars are like driving a video game and all the electronics scare me. I have read so many reviews of all types of cars and it seems people have problems ranging from annoying to serious stuff and multiple trips to the dealer. I am old school because I am old. Have a video display of the speedometer, tach and other guages rather than real needles is just wrong. Having a rotating knob to select the gear is just wrong. Having the car shut down at a stoplight is just wrong. Some of the electronics are good like blind spot monitors. But driving assist features, no way. Just leads to more distracted driving. Just because you can do something cool with technology does not mean you should always use it. Old baby boomer rant for today. Time to put us out to pasture.

I think I will take a cruise in my 1968 Mustang California Special today.