Scratching my head...

[koda2000]

Be sure to bypass the heater core with a double ended barbed hose connector so the sealer doesn't clog the heater core.

Yeah, I just watched a YouTube video where a guy used Blue Devil in a 4 cylinder Toyota. He turned off his heater as instructed, but it completely clogged his heater core. He said it ended up costing him around $1000 and multiple trips to his mechanic to get everything working correctly again and that Advance/Blue Devil refunded his purchase price for the product, but that was all. Of course you don't know what the state of his cooling system was before he put the product in and some vehicles don't stop flowing coolant through the heater core just because you turn the heat off. At any rate, using a product that requires you do drain the antifreeze and replace it with water is out of the question until springtime.

 

[Stick4503]

You only have to run it without coolant for the time you are doing the repair. Mine was only for a few hours until I refilled the system. As for the heater I turned mine ON as directed and ran the product with no harm or damage to the heater core.

 

[koda2000]

You only have to run it without coolant for the time you are doing the repair. Mine was only for a few hours until I refilled the system. As for the heater I turned mine ON as directed and ran the product with no harm or damage to the heater core.

Maybe his issue was mis-reading/not reading the directions. I'll leave it to the vehicle's owner as to if/when he wants to try a sealant. I'm a big fan of K-Seal for coolant leaks and they say it can be used for head gasket leaks, but I feel something stronger is warranted in this instance. As I mentioned, he has another car to drive in the meantime. Waiting until April sounds good to me, LOL. The part that's going to take the most effort and time is figuring out which cylinder is leaking so the spark plug can be removed.

Thanks everyone for giving us a glimmer of hope. I'll eventually let you know how it turns out.

 

[radman]

Look at the spark plugs

Usually this kind of leak into the combustion chamber can easily be found by pulling the plugs and looking at their color or unusual deposits from the coolant being in the cylinder. Coolant can turn to steam and clean the plug in the chamber making it obvious as to which cylinder is the problem.

 

[koda2000]

Usually this kind of leak into the combustion chamber can easily be found by pulling the plugs and looking at their color or unusual deposits from the coolant being in the cylinder. Coolant can turn to steam and clean the plug in the chamber making it obvious as to which cylinder is the problem.

True, but this leak is the reverse (exhaust into the coolant with no discernible coolant getting into the combustion chamber).

I've come up with a good way of checking which cylinder is leaking by using my compression tester's hose hooked up to my air compressor. We plan to start with a stone-cold engine, pull the spark plugs, pump air into each cylinder (one at a time) and see which one causes bubbles to appear in the coolant reservoir. I think this will be a more definitive way to ID the leaking cylinder and easier than testing the compression of each cylinder, which may not show up a small gasket leak, which this appears to be as it stops completely once the engine gets up to operating temp. We plan to facilitate this further by leaving the pressure release on the radiator cap open.

I'll post our findings as soon as we get around to doing this, which may not be for a month or two, due to the weather and my schedule.

 

[Flash]

That should work.

I couldn't find my leaking cylinder using the method described in that link I sent you.
So I just stuck the Rislone (Barr's) in and it worked.

 

[koda2000]

That should work.

I couldn't find my leaking cylinder using the method described in that link I sent you.
So I just stuck the Rislone (Barr's) in and it worked.

I appreciate the info. I have a suspicion it may be cylinder #5 that's leaking, so that's where we'll start checking. We'd pulled the spark plugs and I remember that the cyl #5 plug looked different from the others. No deposits, but the porcelain tip seemed to be unusually white compared to the other plugs. I remember thinking that was odd, but I thought it might have been a dirty fuel injector. radman said something about how coolant hitting the plug might "steam clean" it. Once we figure out where the leak is we'll decide on a product to try sealing it.

I'd been devoting a lot of time on my '01 Sport Trac resurrection project all summer and into the fall. This has allowed my to-do list to get a bit long on my other vehicles. I need to replace the fuel pump and battery on my '01 5.0L EB, replace the cam synchronizer on my daughter's '00 Mountaineer 5.0L and determine if it has a bad blend door actuator or a broken blend door. I also need to replace the intake gaskets on our '97 Sport SOHC 4.0L. I did manage to rebuild the front driveshaft CV on my other daughter's '00 Mountaineer AWD and replace the fuel pump in the '00 Expl 5.0L XLT (AKA "the spare truck"), but it also needs to have the rear pinion seal replaced. It never ends when you maintain a fleet of older vehicles. The neighbor's head gasket problem can wait... LOL.

 

[koda2000]

Update (of a sort):
I've finally gotten far enough ahead on my own projects/repairs to get back to my neighbors blown head gasket problem, plus today's weather was highly conducive to working outside without me having to watch my 3 1/2 year old grandson.

I got the front end jacked up and on safety stands and removed the front tires and inner fenders. Then I removed all 6 spark plugs, being careful to stick them in a piece of cardboard labeled with which cylinder they came from. On examination, 5 of the plugs looked pretty normal (mostly tan colored with some white) but the center plug on the passenger side (cylinder #2 ) was brilliant white with no tan at all.

Tomorrow (with the help of my son-in-law) I plan to get the #2 piston to TDC on the compression stroke, open the pressure release valve on the radiator cap, then put 120 PSI of air pressure into that cylinder via the spark plug hole and see if that produces any bubbles in the coolant reservoir. If it does that's were the leak in the head gasket is. If not I'll check the other 5 cylinders in the same way. Hopefully this will allow me to run the engine with that spark plug removed and fuel injector disconnected while I put in the head gasket sealant. I figure it's a "Hail Mary" shot, but it's worth a try.

Here's hoping.

Question:
I noticed that this truck has the vacuum operated heater control valve on the heater hose. If I unplug the vac line to the valve (or leave the TEMP all the way on COLD) will this prevent the coolant from flowing through the heater core? I would assume it would. I don't want to take a chance on the head gasket sealant clogging the heater core and leaving the valve OFF would be easier than disconnecting/looping the header hoses.

 

[koda2000]

So this afternoon I tried to get cylinder #2 at TDC and applied 120 PSI of air pressure through the spark plug hole. The problem is that with all the spark plugs out the air pressure makes the engine roll and then the exhaust valve opens and lets the pressure out before I can tell if the air is leaking into the cooling system.

When my son-in-law gets home tonight I'll have him hold the crankshaft from turning. I could reinstall the other 5 spark plugs, disconnect the #2 fuel injector and start the engine to see if I'm still getting bubbles in the coolant reservoir, but I'd rather not do that unless I have no other choice.

 

[koda2000]

Update: Putting 120 PSI of air into cyl #2 did not show bubbles in the rad, but I don't know if that constitutes a valid test. I disconnected the fuel injector for cyl #2 and I will replace the other five spark plugs and run the engine tomorrow and see if I still get the bubbles. Thankfully injector #2 is the easiest on to get at.

 

[koda2000]

Today's Update:

I reinstalled the 1,3,4,5 & 6 plugs today and ran the engine with the #2 spark plug out (awful noise BTW) and I still got exhaust into the cooling system, so cyl #2 is NOT where the head gasket leak is (despite the unusually white insulator on the #2 spark plug).

I'm going to purchase the 14mm compression tester hose and start checking the other 5 cylinders with my compressor. I'd check the compression but the leak is so small I doubt a compression test will tell me anything. I'd try running the engine without the other plugs installed (one by one) but most of the fuel injector electrical connectors are too hard to get at.

I'll let you know what I find next week.

 

[C420sailor]

Damn koda, this one is still giving you headaches? I'm curious to see what the culprit is---has to be one of those jugs.

 

[koda2000]

Damn koda, this one is still giving you headaches? I'm curious to see what the culprit is---has to be one of those jugs.

Yeah, it's turned out to be a real PITA. I hope to know which cylinder it is by next weekend. With my luck I'm betting I'll end up having to check all 5 remaining cylinders before I find it.

I'm thinking I can leave the 25' air hose connected and just run it away from the truck to avoid having to unplug all the fuel injectors if I test it with the suspected plug out and the engine running. Maybe I'll be able to find it with just the compressor.

 

[koda2000]

Update:
Not much of an update, but I received my 14 mm quick disconnect compression testing hose last week and it looks like it will be just what I need to either pump air into the remaining 5 cylinders, or give me a way to direct air & fuel mix away from the truck while running it with each spark plug out w/out disconnecting fuel injectors. I'd hoped to work on it this weekend, but other stuff has gotten in the way and next week I have to house/dog-sit for my daughter while she's on vacation. After she gets home I'm having cataract surgery so it could be a while before I can get back to this mystery. I'll let you know when I know something new.

 

[Flash]

I never did find out which cylinder was the culprit with mine, I ended up just tipping the stuff in and it worked.
It was a very small leak.

 

[koda2000]

Update:
Today I finally got around to running the engine (using my 14mm leak down test hose) removing each spark plug one at a time. I attached the leak down hose to a 50'x3/8" air hose, using a quick disconnect fitting, and ran it away from the truck so I didn't have to disconnect all the fuel injectors during testing.

Unfortunately, even with the spark plugs out I was still seeing bubbles in the expansion tank. I may have seen smaller/fewer bubbles with the #5 plug removed, but it's hard to say for sure. This might have been due to the fact the the hole in the leak down hose fitting is quite small and perhaps not enough compression pressure was being released. IDK... I decided against trying to pump 120 PSI of air into each cylinder as it's too hard to do w/out the engine rolling.

At this point I think the only reasonable thing to do is to toss in the head gasket sealant and see what happens. I'm not very hopeful, but some have reported success with a similar leak. If that doesn't work (and I doubt it will) the remaining choices are replace/rebuild the engine or scrap/part out the truck. I leave that choice to my neighbor. There's a guy advertising his business on CL as a Ford OHC rebuild expert. He get's $1700 for a rebuilt 4.0L SOHC long-block. Is it worth it for a 2002 + my labor? IDK and it's not my choice to make.

We're going to try the new Bars Leak Head Gasket & Cooling Sealant with Carbon Fiber. It's easy to use, has really good reviews and it's worked for people with the same symptoms we're experiencing. Fingers crossed...

 

[Flash]

Update:


We're going to try the new Bars Leak Head Gasket & Cooling Sealant with Carbon Fiber. It's easy to use, has really good reviews and it's worked for people with the same symptoms we're experiencing. Fingers crossed...

Ooooooo, carbon fibre; should be good

It'll probably be ok, it's only a small leak.

 

[koda2000]

Ooooooo, carbon fibre; should be good

It'll probably be ok, it's only a small leak.

Plus it it will look really cool.

 

[koda2000]

Update:
I bought the Bars Head Gasket Repair with Carbon Fiber at Advance. This evening (following the instructions to the letter) I drained off about a quart of coolant from the radiator, shook the bottle very well, poured it in the radiator, turned the heater and blower fan on maximum, started the engine and let it idle until the engine reached normal operating temp and the thermostat was open (around 30 mins). Then I turned the engine off for 30 mins, refilled the radiator and expansion tank (didn't need much), restarted the engine and let it run at 1200 RPM (by putting a thin piece of cardboard on top of the TB plate stop screw) for 15 mins and turned it off. Tomorrow I'll check the coolant level again and top off as necessary, as instructed.

Other than for the first minute or two I saw no bubbles in the expansion tank. That doesn't mean some exhaust gas wasn't still leaking into the cooling system, but it's a promising sign. It had been bubbling pretty constantly. Tomorrow will be the real test when I take it for a spin and later release the radiator pressure cap valve. I'm cautiously optimistic. Reading the box it sounds like it's supposed to work on the particular list of problems we're experiencing and it's guaranteed for as long as you own the vehicle. The customer reviews were very positive with only 1 person saying it did not work for them. If it doesn't work, apparently Bars will refund your purchase price, so what do we have to loose?

 

[koda2000]

Update:
It's been 5 days and several 100 miles since we put in the Bars Head Gasket Repair. There has been significant improvement, but there are still bubbles in the overflow tank, which I believe stop once the engine is up to normal operating temp.

The engine no longer pukes and overflows the overflow tank while warming up. In fact the level of coolant in the overflow tank remains constant hot or cold.

The engine is no longer overheating. The needle on the temp gauge behaves normally never going higher than just below 1/2 way.

So the truck is derivable, for how long it's hard to say. It's being driven daily for short trips. As the only spark plug that maybe made any difference in the number of bubbles appearing on the overflow tank was #5 , we may try running the engine with that plug out (with fuel injector disconnected) for 30 mins to see of that will allow the Bars to seal better. Beyond that there's nothing more I can suggest.