How do I know if I have a bad head gasket?

[SDJunkMan]

While plowing snow last week my CUCV overheated. I had it plugged in for about an hour and a half, then started it and let it warm up for 15-20 min while clearing the windows and shoveling a little snow. I drove it about 2 miles, up a pretty steep hill, then it overheated. It was -18 degrees out, and I thought the coolant might have been a little weak, possibly frozen in some of the hoses, since the heater was just blowing cold and it was making weird noises, like possibly ice melting then flowing through the system. I let it cool down and limped it home. Steam appeared to be coming from the radiator, behind the fan shroud. I let it cool down, loosened up the shroud so I could see the radiator, then filled it with coolant and started it up, looking for leaks. Didn't see any so thought I was good.

Out plowing again today, and it starts to overheat again. Let it cool down, and added 2 1/2 gal of coolant. No apparent leaks. I have not noticed any leaks under tne vehicle, the oil is not muddy, and coolant looks fine.

I know 6.2's are prone to blowing head gaskets, so I am wondering if that my problem. Any ideas?

 

[Itali83]

Start it with coolant full and cap off. If it starts bubbling and pushing coolant, cracked head or head gasket.

Ben

 

[rusted nuts]

Look for puffs of white smoke from ex pipe also.

 

[SDJunkMan]

Start it with coolant full and cap off. If it starts bubbling and pushing coolant, cracked head or head gasket.

Ben

I'll try that.

It smokes a little when cold, but as soon as it warms up, the smoke goes away, no steam.

Also, after it overheated, I filled the overflow reservoir, and it is still full, even though the coolant level apparently went down, wondering if I may have a bad cap.

 

[SDJunkMan]

Ok so I topped off the coolant the other day, let it run for a while and looked for bubbles, didn’t see any, so took it for a drive. It started hissing coolant after a couple of miles. Limped it home and pulled the shroud since it appeared to be leaking behind it. Finally saw where it is leaking. Too damm cold to work on it so let it sit.

Pulled the radiator today and found the problem, a crack or two where the tanks mount. They appear to have been fixed at one time, but either cracked more, or whoever fixed it didn’t do a very good job. Can I just solder these, should I stop drill them, or is it not worth repairing?

 

[Rickf]

If it was mine I'd get out the steel wool, 60/40 solder, some flux and a propane torch.

 

[rusted nuts]

I have soldered one or two of them. Acid core solder and good flux + clean and bright. Don't get it to hot

 

[SDJunkMan]

Do you think I should stop drill the cracks, or just solder them?

 

[rusted nuts]

I never drilled them.