Lack of compression
If the motor will start and idle- let it warm up then carefully remove the radiator cap while the motor idles, if you see small bubbles coming to the surface in the radiator it is a blown head gasket. Replace gasket promptly it can do damage to the motor.
what are you asking here? PLease be more specific ...like - how do I know if my head gasket is blown, or what do I do about a blown head gasket ......
ckeck the oil dipstick if the oil has a color like chocolate milk the oil has water/colant in it which means the head gasket is blown and its leakin water into the engine block
perform a pressure test on the cylinders. if they don't hold pressure it's a blown head gasket
It does not matter. If one is blown on a V6 or V8 then you need to replace them both.
my head gasket was blown and it had water in the oil which made the oil look a milky color
Do a compression test.
There are several possible indications of a blown head gasket: If the head gasket is blown between adjacent cylinders there will be poor or no compression in either cylinder. Poor compression in any cylinder can be caused by a blown head gasket. That condition can also be caused by a burned valve or piston. Coolant in the crank case can be caused by a blown head gasket. Compression in the coolant can be caused by a blown head gasket. An engine with a blown head gasket usually loses performance and runs poorly or not at all.
If you have a blown head gasket. you pour it in the radiator and it's suppose to fix your blown head gasket. I've never used it so i don't know if it actually works
You will not know until your remove the head. You have to remove the head in order to replace the gasket and once you have the head removed have it magna fluxed at a machine shop. That will reveal any cracks.
You won't know till you tear into it, but it may just be a head gasket and you fouled a couple of cylinders. I doubt the motor is blown. Cooling fan or sensor is bad, the car over heated and warped the head causing the gasket to leak.
if you have water in the oil that's your problem.