Coolant Leak Between Head and Block

[richard wysong]

WOW that sucks! I wonder if the water is just condensation from the coolant in the exhaust system. when you do the pressure test pull the plugs and see if the parts store has 1 of those cameras you can look in the cylinders with. drain the oil after it sits for a day or so and see if any coolant s present. it will be the first thing out the drain hole as its heavier than the oil. does it still have the external leak you started with? if you can't find the leak right off try manually turning the engine over while under pressure and keep looking in the cylinders in case its a cracked head in the valve pockets or hairline crack in a cylinder wall. if I remember correctly you just had an external leak to start with so you may have a bad head

[EightTrackHits]

34 minutes ago, richard wysong said:

WOW that sucks! I wonder if the water is just condensation from the coolant in the exhaust system. when you do the pressure test pull the plugs and see if the parts store has 1 of those cameras you can look in the cylinders with. drain the oil after it sits for a day or so and see if any coolant s present. it will be the first thing out the drain hole as its heavier than the oil. does it still have the external leak you started with? if you can't find the leak right off try manually turning the engine over while under pressure and keep looking in the cylinders in case its a cracked head in the valve pockets or hairline crack in a cylinder wall. if I remember correctly you just had an external leak to start with so you may have a bad head

The external leak is gone.  I've not found any others.  I did get rebuilt heads for this job as the old ones were castek and I would have worried knowing there as a TSB on them.  We'll see what happens when I get it under pressure.  Perhaps I can find a camera around here.  Big fear is I was too aggressive cleaning the block. 

[richard wysong]

the cameras aren't a lot of $ if the parts store doesn't have a loaner. Harbor freight has them I think. hopefully the leak isn't elusive. you would have had to have taken a divot out of the block for it to be your fault, not likely the wiz wheel would have taken enuff off for a leak, if you used quality gaskets and properly torqued every thing its probably a bad head. you may have to have them pressure tested at a machine shop to find it if it doesn't show in your test

[Supreme Pizza]

My suggestion is that you give up and use a coolant sealer.

 

I have used this stuff plenty of times, and it has always worked.

 

Its not going to damage anything, and if it works - it only cost you $12.

 

 

Yes, Yes, I know - Band-aids and snake oil are not good- I know. I agree that normally you want to try to fix it properly if possible, but come on - how many times do you want to pull the heads?

 

I had a lady come to me saying that the shop wanted to charge charge her $3,500 to fix her head gasket. She did not have any money. I bought her a bottle of this stuff out of my own pocket and put it in her car. That was 4 years ago and she never overheats and never has to add coolant. I agree that additives are not always ideal - but they do work in many situations.

 

 

Just pour this in, and call it a day.

 

 

If it doesn't work, fine take the engine apart again - but you have nothing to loose by trying this stuff.

 

 

 

 

 

Edited January 17, 2022 by Supreme Pizza

[EightTrackHits]

I’ve considered a sealant, and have looked into the Barrs products.  But right now I’m into it again.  If the repair doesn’t take this time, I’m definitely trying some.  If the repair works I’m also considering trying some for good measure as I’ve heard the gm factory does something similar.

[KARNUT]

I’ve bought 3 used vehicles that had leaks. My clean Avalanche is the third. All were fixed with bars leak. The second one locked the engine I had to pull the plug to let the coolant out. All the vehicles were used in town always close to home. If the Avalanche engine at 178K presently would fail to take. I’d probably go rebuild with a little juice added. Or sell it with full disclosure to someone at my brothers shop. I’m hitting two years of ownership my usual threshold. I think I’ll keep it though with total confidence in the bars leak.

[Brenden Burnham]

3 hours ago, EightTrackHits said:

I’ve considered a sealant, and have looked into the Barrs products.  But right now I’m into it again.  If the repair doesn’t take this time, I’m definitely trying some.  If the repair works I’m also considering trying some for good measure as I’ve heard the gm factory does something similar.

I had a pretty bad coolant leak was evident near the upper part of the Radiator.  Went into a parts store and an employee told me to try the bars leak heavy duty radiator stop leak that his father swears by the stuff.  I was skeptical but for $8 I had nothing to lose.  Put it in and took it home that night.  Next day I did not see the normal puddle of coolant I normally did under the front of the truck.  I drove it for a couple hours and not a single drop of coolant leaked and the constant smell of coolant was gone.  I did this 3 months ago and still have not had to put a single drop of coolant back in the truck.  I know yours isn't the Radiator but point is some of these so called "snake oils" do actually work.  

Edited January 17, 2022 by Brenden Burnham

[richard wysong]

all manufacturers use a sealant at the factory to insure no seepage leaks, I believe GM uses Bars Leaks. I once had a Chrysler K car that was given to me with a head gasket that was so bad that every time the piston came up it would shoot the coolant out of the rad cap 5ft in the air. I used that head gasket in a can where you have to flush the system and disable the fan so it gets very hot, I understand it creates a glass like coating in the engine. it worked! I took that car and entered it in a 100 lap enduro race and it never overheated

[EightTrackHits]

The pic shows the cap I made for pressurizing the system.  I took a coolant reservoir cap, popped off the top, took out the diaphragm, drilled a hole through the bottom, set in the air fitting with JB weld.  I then leveled the epoxy, drilled a hole through the top to clear the fitting and snapped it back together.  Kits like this can be rented, but I want to use my shop air regulated to around 12 psi and listen for leaks.  I’ll let everyone know how it goes.

 

 

[Supreme Pizza]

You might want to bypass the heater core before you pressurize the system. They have flow restrictors and other things to protect them, because they are very fragile.

 

Some people become suicidal when they realize that the heater has failed.....

 

 

 

 

 

 

 

 

 

 

 

[EightTrackHits]

17 minutes ago, Supreme Pizza said:

You might want to bypass the heater core before you pressurize the system. They have flow restrictors and other things to protect them, because they are very fragile.

 

Some people become suicidal when they realize that the heater has failed.....

 

 

 

 

 

 

 

 

 

 

 

Thanks for the heads-up.  I hope I didn’t just learn an expensive lesson!

[EightTrackHits]

I pressurized with as close to 12 psi as I could get.  I heard nor saw no leaks.  The system held the pressure with the air cut off.  
I’ve always suspected the top head bolts due to the good leak down test and the proximity to an avenue for coolant to get into the block.  But I first got the Idea from the below thread page 7 post by krigsby.  A coworker had the same thing happen.

I just now I checked torque with a different torque wrench and had close to 45 degrees movement.  So, re-torquing, putting it back together, oil change and I’ll let you know.  Only re-torquing the top as the leak down was good and I felt the bottoms yeald when I did this initially.  I have a busy week, so it will be a few days before I’m done, but I will follow up.

 

[Supreme Pizza]

I'm not sure how well re-torquing TTY bolts will work out. Its worth a shot I guess.

[EightTrackHits]

1 minute ago, Supreme Pizza said:

I'm not sure how well re-torquing TTY bolts will work out. Its worth a shot I guess.

From what I understand, the top bolts are not TTY.

[Supreme Pizza]

6 minutes ago, EightTrackHits said:

From what I understand, the top bolts are not TTY.

 

 

 

 

   Right. Now I remember. They are also a little shorter than the lower TTY bolts, right?