Blown Head Gasket repair cost?

[Grandpa_truck]

Sir,

You will find your real answer by quantifying exactly how much coolant your engine is either leaking and/or
consuming.

IF the amount is zero coolant loss over time, then you can leave the engine as-is and instead focus on
why you are occasionally generating more BTUs with your engine than your fan/clutch/radiator combo can
get rid of. For what it's worth, I've attached a hand-drawn chart showing an 'intermittent' failure from
excess heat. (Note: I originally drew it for an electronic issue, but if in your mind you substitute weakened
clutch, or scaled up radiator internals, etc., for why the system can dispose of less BTUs then when it came
off of the assembly line then you will catch my drift.)

****

On the other hand, IF you are losing/consuming coolant, then the only answer is to locate the root cause
and fix that. But if you haven't already done so, make sure your overflow tank has a good hose connecting
it to the radiator, make sure it's clean enough to see the coolant level, and then put a Sharpie mark right
at the Cold Fill level, and pay close attention to where it returns after it cools overnight for several days in
a row so that you can quantify how much coolant is disappearing, if any.

Here's hoping you are not using any coolant, and all you have to do is hot-rod your cooling system like
what our Texans are doing. (L31MaxExpress & others.)

Let us know what you discover. Best of luck!

Well… it’s back. Truck is NOT over heating, as confirmed by gauge in cluster and IR temp gun. Truck runs fine, AC is working, no loss of power. But pulled in driveway after 7 mile drive from work and coolant is bubbling into overflow tank doesn’t return to rad. I could t imagine a head gasket leak without, white smoke, coolant loss, or over heating, usually those are the big 3 precursor to head gasket. I replaced the rad cap, overflow cap, and put a new 195 tstat. I am not losing coolant, (not gaining it back to rad from overflow either) I do not see any viable leaks, and I’m now curious as to the condition of the radiator. It’s pretty funky, fins aren’t in great shape and it just looks rough, inside and out. But again no noticeable coolant loss. I’m at my wits end with this one. I have a video of the tank bubbling

C1500

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***** I let it cool and popped rad cap off and now overflow tank is returning coolant to radiator. But doesnt do that when cap is on… brand new cap too. Very odd

 

[Scooterwrench]

As the engine heats up and the water expands it gets pushed into the recovery tank and the tank level rises. The water will remain in the tank while the engine is running and not return to the radiator until the engine begins to cool and the water contract. If your recovery system is working correctly the radiator will be full when the engine cools. From your description it sounds like you have gotten your moneys worth out of that radiator,time for a new one.

 

[SableSlayer]

Well… it’s back. Truck is NOT over heating, as confirmed by gauge in cluster and IR temp gun. Truck runs fine, AC is working, no loss of power. But pulled in driveway after 7 mile drive from work and coolant is bubbling into overflow tank doesn’t return to rad. I could t imagine a head gasket leak without, white smoke, coolant loss, or over heating, usually those are the big 3 precursor to head gasket. I replaced the rad cap, overflow cap, and put a new 195 tstat. I am not losing coolant, (not gaining it back to rad from overflow either) I do not see any viable leaks, and I’m now curious as to the condition of the radiator. It’s pretty funky, fins aren’t in great shape and it just looks rough, inside and out. But again no noticeable coolant loss. I’m at my wits end with this one. I have a video of the tank bubbling

C1500

New item added to shared album

photos.app.goo.gl

***** I let it cool and popped rad cap off and now overflow tank is returning coolant to radiator. But doesnt do that when cap is on… brand new cap too. Very odd

I just found a bad combustion leak on my 98 that I had no idea was even there cause the truck would only get hot on a 100 degree day after pulling the camper. No coolant lose or anything.

I was chasing a misfire under load like when pulling the camper up hill. It was a cylinder 3 mis and after doing everything else possible (3 times) I decided to try upgrading the valve springs since it was the last thing to try without removing the heads.
I compressed the cylinders with air for this. Bank 1 went just fine. When I hooked up with cylinder 4 on bank 2 and turned on the air within seconds the cooling system was filled and bubbling over. When I removed the radiator cap the coolant was flowing out.
So the air that was going into cylinder 4 spark plug to compress the valves closed was dumping into the coolant system.
I ended up pulling the heads which only took 2.5 hours and found cracks around the exhaust valves on cylinders 4, 5, 6. It was disappointing but at least I finally found the problem I've been chasing for 4 years. I think the only reason why I never noticed it getting so hot is due to the monster cooling fan setup that's on it.

 

[Grandpa_truck]

As the engine heats up and the water expands it gets pushed into the recovery tank and the tank level rises. The water will remain in the tank while the engine is running and not return to the radiator until the engine begins to cool and the water contract. If your recovery system is working correctly the radiator will be full when the engine cools. From your description it sounds like you have gotten your moneys worth out of that radiator,time for a new one.

Interesting you should say that, as every time I pop the hood that craggly radiator glares at me begging to be changed. I think even if it turns out not to be the prime issue it certainly ain’t helping matters. Thanks!

 

[Scooterwrench]

Interesting you should say that, as every time I pop the hood that craggly radiator glares at me begging to be changed. I think even if it turns out not to be the prime issue it certainly ain’t helping matters. Thanks!

If you do have a head gasket issue that crusty radiator could very well been the cause of it so you're not going to want to run it after you replace the head gaskets if you need to. Start there first.
When I bought my truck one of the first parts I replaced was the rad. There was a glob of JB Weld on the top of the left side tank that was holding but I know from past experience that was only a temporary condition.

 

[scott2093]

The biggest culprit I've discovered for a non-working recovery system is bad radiator cap. Your rad. cap has two seals. The lower seal seals on the lower shelf in the rad. neck and that is the one with the spring for the rated pressure. The upper seal seals the top of the rad. neck and keeps coolant from just flowing out and down the side of the tank. If that seal fails it will coolant will leak out and maybe at such a small amount that it evaporates and not show a leak. When the system cools and pulls a vacuum instead of pulling coolant back in from the recovery tank it will pull air. After repeated cycles of leaking and not replenishing coolant you wind up with low coolant in the rad. It's always good to check your coolant level in the rad. when the engine is dead cold. The water level should be right up to the lower shelf in the neck where the main cap seal sits. If it is low than you have a problem with your recovery system. The upper seal is a thin rubber washer and I've seen those completely gone.

I forgot to mention the radiator cap is a brand new Delco. Well it was installed with the new pump and thermostat...
My level is always right at the top.Like almost too full where it seems like it wants to spill out but it doesn't. If that makes any sense....

just real quick....after a few hundered mile trip I'm pretty sure my overflow tank has gotten a tiny bit lower.....
Radiator still full...
What's weird is I still never see any action in the overflow but, if it's 1/4" lower than when I last checked, something is going on?
Now when I idled the truck for a few minutes and let it sit for a few, I crack the cap just a tiny bit and the overflow starts bubbling......
So the pressure does get to there.....
Could my brand new cap be blocking pressure from releasing??? That would mean it's putting pressure on my gaskets?
I don't like this....

 

[Scooterwrench]

just real quick....after a few hundered mile trip I'm pretty sure my overflow tank has gotten a tiny bit lower.....
Radiator still full...
What's weird is I still never see any action in the overflow but, if it's 1/4" lower than when I last checked, something is going on?
Now when I idled the truck for a few minutes and let it sit for a few, I crack the cap just a tiny bit and the overflow starts bubbling......
So the pressure does get to there.....
Could my brand new cap be blocking pressure from releasing??? That would mean it's putting pressure on my gaskets?
I don't like this....

Unless you look very closely where the recovery line goes into the tank you won't see any action, the transfer of coolant from and to the radiator is pretty slow and only happening as the engine is warming and cooling down.
Your cooling system is intended to be pressurized for two reasons. One, to raise the boiling point of the water and the other, to increase the heat transfer from the hot components into the coolant. Your cap should have a pressure rating on it somewheres between 13lbs and 20lbs. As the water expands the cooling system is going to build that much pressure before it can lift the valve in the cap and allow the pressurized coolant to escape and flow back into the rec. tank. 13-20lbs is not nary enough to push water through a gasket unless the gasket is deteriorated. You will blow a hose or blow the tanks off the radiator before you blow a gasket.
Just as an example circle track cooling systems run no coolant/antifreeze and up to 40psi cooling systems.

 

[scott2093]

Thanks. The Delco cap is 15psi....
Like I've said too many times before, it just makes me uncomfortable never to see my recovery tank filling...it never moves. And I've been checking quite a bit.....
And it used to be at hot level after driving, cold level after sitting.....
Ever since new water pump, thermostat and cap, has it started this behavior.....

Radiator is less than a year old...

 

[Scooterwrench]

Thanks. The Delco cap is 15psi....
Like I've said too many times before, it just makes me uncomfortable never to see my recovery tank filling...it never moves. And I've been checking quite a bit.....
And it used to be at hot level after driving, cold level after sitting.....
Ever since new water pump, thermostat and cap, has it started this behavior.....

Radiator is less than a year old...

If the rad. is staying full and you're not overheating you're good to go. It could be you were running hotter before you changed the rad. and thermostat and it was pushing more water into the rec. tank. The hotter water gets the more it expands. Just keep an eye on the cold level when it's cold and pop the cap off to make sure the rad. is full.