Castech heads........I know, not again.

[DAWIFESHOE]

Noob here. Although I'm looking for some feedback, I'm hoping this post will be of some value as well.

Looking to purchase an 05 Tahoe but.......................

So I've researched this pretty thoroughly and just wanted to run one thing by you guys. During my presale vehicle inspection the inspector was detecting CO2 (although I suspect he meant C2O2) in the coolant overflow tank at the rate of 0.8%. This was indicating to him, and I'd have to agree, that somewhere there's a leak between the cylinder head and the cooling system.

My father owns this vehicle now so I know he's telling the truth when he says he hasn't had to add any coolant to the system, although it's just currently under the low mark.

Would anyone agree that this is a good precursor to the Castech Head issue? Seems to me that this might be the earliest signs of this problem.

I did read in another post somewhere, where a guy used some Bar's Stop Leak at the earliest stages of this same problem and has put an addition 70k on his engine without losing a drop of coolant. Do you think that's a reasonable approach as long as I keep an eye on the coolant level?

Fortunately I may have an out. Dad purchased the 100k/72 mo extended warranty and the rig has 97k right now. I should know tomorrow and have high hopes as this was not a GM warranty, but an independent company. And I've got to imagine this is a Powertrain issue.

THX,
Mike

 

[MASS-HOE'Z71]

Do you have the castech heads? This was supposedly not a very common problem and seemed to be signaled by coolant loss without a visible leak or a block test to check for carbon monoxide in your coolant. Does the engine overheat or blow white/ blue smoke out of the exhaust? Did the inspector do a coolant pressure test? If your feeling motivated, pull the valve covers and check for a castech logo, if you dont have one, i'd lean more towards a failing head gasket. Hopefully You dont have any problems getting the 3rd party warranty covering repairs

 

[DAWIFESHOE]

Any recommendations on how to best apply the GM (Bar's) Seal Tabs?

I know it requires 5/6 tabs (crushed) and inserted into the fill or top tube (not the surge tank), but since the radiator probably hasn't been flushed since new, should I flush and refill before adding the tabs? Or, add the tabs and run the engine per the instructions and then flush. Flushing first seems to be the smarter way to go in case there's any build-up in the cooling system. I don't want to create any unecessary plugging of the cooling system.

 

[ezdaar]

Any recommendations on how to best apply the GM (Bar's) Seal Tabs?

I know it requires 5/6 tabs (crushed) and inserted into the fill or top tube (not the surge tank), but since the radiator probably hasn't been flushed since new, should I flush and refill before adding the tabs? Or, add the tabs and run the engine per the instructions and then flush. Flushing first seems to be the smarter way to go in case there's any build-up in the cooling system. I don't want to create any unecessary plugging of the cooling system.

Yea, DONOT USE THEM!I put some in my 3rd S10, they clogged my radiator so bad i had to replace it!
From then on my coolant was SHIT brown! No matter how many times I flushed that toilet it was always shit brown!

DONOT PUT THAT CRAP IN!

 

[BOSS]

X2 unless it's a leak in the core that a you absolutely cannot replace, do not use that. The better of those btw has copper in it.

Bp