Possible blown headgasket?

[Rogue Leader]

I really think my headgasket is blown. To start this is my prior thread:

http://www.camaro5.com/forums/showthread.php?t=469756

I thought i solved my problem, but it seems not. Mind you the car sits a lot so the reason I didn't see this sooner is I have literally put maybe 300 miles on it in the past year.

So anyway the TL DR is I have replaced the entire cooling system in my car, water pump, thermostat, temp sensor, radiator, and even the overflow tank. When completed the car was filled with a perfect 50/50 Dexcool and distilled water. I do not believe I am burning coolant as I am not getting consistent white smoke out the exhaust or anything like that, nor have I noticed coolant loss.

BUT when I park the car I get a faint boiling sound coming from the coolant overflow tank. It lasts for minute or two and then stops. I am not leaking anything, and the car runs perfectly, doesn't feel down on power, cools properly, temp is fine, fans work, etc. Before I swapped all the cooling parts (see prior post) boiling sound was VERY loud and noticeable and lasted a while. Now its just a faint sound, but enough that you can notice it in the garage, but it stops after a minute or two.

Am I losing my mind? Anyone elses car do this? I'm really thinking the head gasket may be blown and somehow something is causing the coolant to boil (I guess if the gasket blew between a coolant passage and a cylinder)?

EDIT: So now the car has cooled a couple hours. Radiator is full to the top. Overflow is bone dry. I am now leaning more towards the headgasket being blown. Checked oil, looks clean, no coolant. Where the hell else could the coolant have gone but burned off from a blown headgasket?

[hunter1660]

Might be something as simple as the radiator cap. The system is a closed system so it's not boiling off. Keep filling it and you'll find where it's going eventually. Good luck

[Rogue Leader]

Originally Posted by hunter1660

Might be something as simple as the radiator cap. The system is a closed system so it's not boiling off. Keep filling it and you'll find where it's going eventually. Good luck

Been through TWO new GM radiator caps. The overflow doesn't seal like the one in a Corvette, so it could boil off, or in tiny bits its being boiled inside the motor. Or another thought, even when burping it I never got it perfect and I was just short coolant (hence the empty overflow). driving me insane, about to just turn around and bring it to a local Corvette race shop.

[Rock-It Man]

You didn't mention anything about the oil cooler. Coolant is routed to and from the oil cooler, so I suppose you could be losing pressure there.

Coolant boils when the system is not pressurized. Your dealer or other mechanic can pressure test the system. It does seem odd, though, that all this is happening without any coolant loss or odor.

[Rogue Leader]

Originally Posted by Rock-It Man

You didn't mention anything about the oil cooler. Coolant is routed to and from the oil cooler, so I suppose you could be losing pressure there.

Coolant boils when the system is not pressurized. Your dealer or other mechanic can pressure test the system. It does seem odd, though, that all this is happening without any coolant loss or odor.

Nope I didn't touch that, I would assume if I was losing pressure there somehow it would either be leaking or getting into the oil, and its not in the oil nor is anything leaking.

One thing I did not mention is that the drivers headgasket was replaced by the dealer about 19k miles ago. I had a collapsed valvespring, and they removed the head to replace it. Its yet another reason I believe the head gasket could have failed, I am thinking maybe the head wasn't torqued properly and may have caused that gasket failure.

I did lose some coolant, but just what was in the overflow, and IMO its still possible there was air in the system as I was having a real hard time "burping" the system. Also being that it was boiling, it could have boiled off....

[Rogue Leader]

UPDATE:

Spoke to the Vette race shop that I use, Vette Doctors, they believe its probably the headgasket and the "boiling" noise is the exhaust gasses getting into the coolant through the opening in the head gasket.

While I'd love to do the repair myself I don't have the time right now, I have a ton of work to do on my Race car, so I'll probably be bringing it there...

[Dizzy82]

My experience overflow tank was bone dry, leaking headgasket. Headgasket was replaced, consistent level in the overflow tank.

[Rogue Leader]

Originally Posted by Rock-It Man

You didn't mention anything about the oil cooler. Coolant is routed to and from the oil cooler, so I suppose you could be losing pressure there.

Coolant boils when the system is not pressurized. Your dealer or other mechanic can pressure test the system. It does seem odd, though, that all this is happening without any coolant loss or odor.

So I had to quote you again, because you were right. I got my car back and the failure was..... The fitting to the block from the oil cooler. It was a small leak, that wasn't coming out quickly (and never left a spot) but blew out when they pressure tested the system.

New fitting, coolant flush, testing, etc and I'm back on the road without rebuilding the motor. Thanks for the help all!

[sherob]

That's great news. Usually if you had a blown/cracked gasket, you can check your oil (dipstick) and you would see a white viscous mix in it from the coolant/water. BTDT

[Rock-It Man]

Originally Posted by Rogue Leader

So I had to quote you again, because you were right. I got my car back and the failure was..... The fitting to the block from the oil cooler. It was a small leak, that wasn't coming out quickly (and never left a spot) but blew out when they pressure tested the system.

New fitting, coolant flush, testing, etc and I'm back on the road without rebuilding the motor. Thanks for the help all!

Great!

[Rogue Leader]

Bad news....

1000 miles later and guess what the car is doing?

Boiling the coolant out the overflow.

Spoke to Vette Doctors again and its headed there next week (I have 0 time to deal with it right now I'm in the middle of both an engine build for my race car and a suspension/brakes rebuild on my Alfa). We are now leaning further toward either the headgasket being blown or improperly installed.

If its improperly installed I guess I am in for an interesting situation getting the dealer/Chevy to cover the repair since the headgasket install was done WRONG under warranty.

[Rogue Leader]

I am the dumbest worst mechanic ever.

The overflow hose and hose that goes to the head were switched (that go to the top of the radiator), this was the cause of the past couple years of this BS. I must have done it when the radiator blew, in my haste to swap it in the cold of November 2016.

All fixed.

I need to go turn in my wrenches and man card.

[CamaroFred]

Originally Posted by Rogue Leader

I am the dumbest worst mechanic ever.

The overflow hose and hose that goes to the head were switched (that go to the top of the radiator), this was the cause of the past couple years of this BS. I must have done it when the radiator blew, in my haste to swap it in the cold of November 2016.

All fixed.

I need to go turn in my wrenches and man card.

Wow! I'm surprised they are the same size.
I'm gonna have to look when the snow melts off the hood.