97 Lumina 3.1L Head Gasket

295,000 KMS ( 180,000 miles) on engine with no previous problems.
Garage done leak down test and found #3 cylinder leaking, and recommended head gasket replacement.
What are chances that the head may be cracked or warped.
Do not want to get into major overhaul.
Thanks

has it ever overheated

Its has never overheated.
In the couple days previous to problem, experienced fluctuations
in temp gauge, indicating overheat and blowing cold air inside car, but depress accelerator pedal to increase engine RPM and heat would return. Lost less that 1 litre of coolant

did you find out where the coolant went?
loss of coolant and overheating(even slight) could cause a warped head but i would have it retested just to make sure

No visible signs of leaks.
Could smell anti-freeze in exhaust, some white smoke.
Garage removed all plugs and performed leakdown test,
reported problem with #3 cylinder only.
I have not checked for any signs of anti-freeze in oil

Thanks

Did the #3 plug show coolant traces? Did they check for combustion gases in the cooling system with a gas analyzer? Was the leak slow/small enough to be undetectable without performing a leakdown test?


Sounds typical of head gasket behavior, yes.

Could be cracked/warped head, but that's less common, especially without an overheat episode.

And the effects are usually more severe if that's the case.

Only way to tell for sure is to tear it down.

Hello! My first post! Your head probably isn't warped or cracked, because these problems are caused by overheating of the engine. Get the head hot and it will warp or crack, or both. White smoke isn't smoke, but more likely steam. Sounds like it is indeed going into the cylinder, and in turn going out through exhaust as steam. It will get worse, and your engine will suffer because of it. Your oil will lose its effectiveness because of the addition of coolant to it. Look for creaminess on the dipstick, as opposed to clear yellow, brown, or black oil. Bad gasket will cause this and will only get worse.

have it tested for warpage or cracks when it is apart because if by chance it is warp or crack you do not want to find that out after it is all back together