My Potato has a Coolant Leak from Unknown Regions

[BRIANGEE]

So my ol' potato has an elusive coolant leak. It drinks about 1 gallon every 10 days or so. I've added UV dye trying to stick a fork in this potato but it has shown up nadda! I don't know where it's coming from but I do know where it's not coming from.

*No indications of head gasket failure - no puff of smoke - no shining cylinders - no UV dye at the tail pipe.
*No coolant in the tranny fluid
*No coolant in oil
*No coolant from pump weep hole
*No coolant from any hose
*No smell or indication of coolant inside at the heater core.
*No nothin' to be perceived anywhere.

I've shined the UV flashlight up down, all around... nothin! Yet the beast still sips it's brew.

You want more strangeness? Okay...I made sure to not spill a single drop of UV dye when I put it in the coolant bottle. The only time I did see anything was a little drop at the screw hole that mounts the bottle to the frame. The screw screws into solid plastic and into the metal. Now how did that happen without leaving some other trace? "It's a Ford!" Despite that mystery I don't think it merits further investigation since a drop is not a gallon and I'm losing it regularly.

Now I know I've come across some stuff in the past saying there's a coolant line under the intake manifold and that's my best guess at this point. That it's leaking and quickly getting evaporated by pooling on top of the hot motor and going bye-bye without a trace... if that's even possible - I mean it's antifreeze after all with a higher boiling point. But my wife and I sometimes notice a stench - possibly of putrifying antifreeze from the beast getting regurgitated.

Now before someone says pressure test it - I've had it pressure tested before and nothing came up. This was back in late november.

This one has had me stumped for a while because this whole vehicle is a cluster of intermittent issues - including coolant loss! LOL What the heck? Who ever heard of...nevermind... it's a ford.

Any ideas?

Thanks,
Brian

 

[1955moose]

Think you nailed it. It's probably that hose. Why not pressurize the expansion tank, and do it right. You put 14 pounds or so on the tank fitting, and it should start spraying. You might need a special Ford adapter, but trying any other way is frustrating. Just remember it's better to find out now your problem, than stuck out in that Phoneix heat waiting for a tow home.

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[BRIANGEE]

Wouldn't be the first time waiting for a tow truck in the heat LOL.
I'll try my hand at pressure testing... the first time was at a mechanics shop with three techs and myself under the vehicle on a lift looking for leaks while under pressure. It just wouldn't leak but had left a puddle at my grandma's house the night before and I saw drips coming down through a hole in the frame that night. That was then - now I'm not even that lucky to see any sign of coolant at all.

If I can get rid of this leak, and then successfully change out what I believe to be a leaking valve stem seal I think I will be in decent shape.

 

[1955moose]

Your comment about the valve guide seals got me thinking, if the intake gasket is leaking above that questionable cylinder, could coolant be making it's way not only into the valley, but dumping some into the intake port of that cylinder. Apparently anything above 150k and the gaskets get brittle, and that's when the fun starts.

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[Trainmaster]

Look at the head gasket above the starter.

 

[Password]

Your comment about the valve guide seals got me thinking, if the intake gasket is leaking above that questionable cylinder, could coolant be making it's way not only into the valley, but dumping some into the intake port of that cylinder. Apparently anything above 150k and the gaskets get brittle, and that's when the fun starts.

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This scares me because I'm at 153k lol. I actually started getting a coolant leak myself a few weeks ago and the expansion tank was empty. I think I figured mine out today, just not sure which heater core hoses is the right one.

 

[1955moose]

Are you replacing a leaking hose up to the heater core? If so, slit the old one where it goes over heater core. I didn't do that on a Camaro engine swap years back. I ended up doing a heater core for free for the guy. Learned never to twist the old hose off again.

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[BRIANGEE]

Your comment about the valve guide seals got me thinking, if the intake gasket is leaking above that questionable cylinder, could coolant be making it's way not only into the valley, but dumping some into the intake port of that cylinder. Apparently anything above 150k and the gaskets get brittle, and that's when the fun starts.

Sent from my N9131 using Tapatalk

In my case I'm not so sure - I would imagine there would be a lot of smoke similar to a head gasket and there is not plus no trace of UV dye in the tail pipe which I would think there should be some trace (maybe not) - but I have verified the presence of oil pooling up on top of the cylinder.

 

[1955moose]

You might have a combo of both. Were the heads redone before you bought your SUV? Valve guide seal failure is pretty rare. The only exception is when somebody reworks heads, or a reman engine. Stock Ford seals usually go the distance. Oil pooling is a sign of seal or worn guide. Either way when it cools down a little for you, and you have the time, your going to have to get dirty! Are you smoking on start up, especially when warm, after you let it sit an hour or more?

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[Password]

Are you replacing a leaking hose up to the heater core? If so, slit the old one where it goes over heater core. I didn't do that on a Camaro engine swap years back. I ended up doing a heater core for free for the guy. Learned never to twist the old hose off again.

Sent from my N9131 using Tapatalk

I think my leak is at this hose, that 3 way union on the underside of it was wet with coolant and there was/is a small puddle gathered at the spark plug well. I'd like to do a pressure test first though, because I'm not 100% sure which part number that hose kit is.

 

[Hamfisted]

Heater hose assembly ..... https://www.amazon.com/Motorcraft-K...automotive&vehicleId=2&vehicleType=automotive

 

[BRIANGEE]

You might have a combo of both. Were the heads redone before you bought your SUV? Valve guide seal failure is pretty rare. The only exception is when somebody reworks heads, or a reman engine. Stock Ford seals usually go the distance. Oil pooling is a sign of seal or worn guide. Either way when it cools down a little for you, and you have the time, your going to have to get dirty! Are you smoking on start up, especially when warm, after you let it sit an hour or more?

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It's all original - I would like for both symptoms to be related but I wouldn't be that lucky. Cylinder 1 has nothing but pure unadulterated oil that pools up over night. Here's an image from my other thread not so long ago:

 

[Don Hall]

Open to correction, but if you are pressure testing at the rad cap neck, you are only pressurizing between the cap and the t-stat (?).

 

[1955moose]

Kinda true, but their is no access to the radiator itself. Brian, Don's right, pull the thermostat and pressurize at the tstat housing. That's how we did it on 4.6 Crown Vic's at my Cab company.

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[Password]

Heater hose assembly ..... https://www.amazon.com/Motorcraft-KH-711-Heater-Hose/dp/B009UOSUJA/ref=au_as_r?_encoding=UTF8&Make=Ford|54&Model=Expedition|662&Year=2006|2006&ie=UTF8&n=15684181&newVehicle=1&s=automotive&vehicleId=2&vehicleType=automotive

Thanks Ham! Is there a recommended heater hose disconnect tool?

 

[Trainmaster]

This one worked for me on my 2008. Not positive they are the same on the 06, but mine has that triple hose with the plastic tee also. Took me about ten minutes to get the hose out.

https://www.amazon.com/OEMTOOLS-271...8-1&keywords=ford+heater+hose+disconnect+tool

Some cheap folks just replace the tee with some plumbing part and hose clamps avoiding pulling the hose at the heater core. There are videos on YouTube of this hack if you really don't care too much about doing the job right.

 

[Password]

This one worked for me on my 2008. Not positive they are the same on the 06, but mine has that triple hose with the plastic tee also. Took me about ten minutes to get the hose out.

https://www.amazon.com/OEMTOOLS-271...8-1&keywords=ford+heater+hose+disconnect+tool

Some cheap folks just replace the tee with some plumbing part and hose clamps avoiding pulling the hose at the heater core. There are videos on YouTube of this hack if you really don't care too much about doing the job right.

Thanks!
Ok, I'm done hijacking BRIANGEE's thread

 

[BRIANGEE]

Okay so I got home and smelled antifreeze and popped the hood. There was leakage which appears to be coming from the cap. The Reservoir which was previously full before my 45-minute trip was now empty. Inside the expansion chamber was a weird looking rubber bushing or something inside the tank itself. I pulled it out and it crumbled in my hands but here's a picture.

 

[BRIANGEE]

Any idea on what the heck that is?

 

[blue oval guy]

With leaks from the pipe in the valley it wouldnt be that severe as to leak a whole gallon in 10 days! The ones we have seen are just minor seepage and maybe light puddling in the block valley.