Cadillac Repair: 97 cad deville/ northstar engine, blown head gaskets, northstar engine

Question
hi, i saw your answer to a question i have about my engine over-heating?, how do i perform the "back cylinder exercise to check for blown head gaskets rather than take to dealer?

Answer
Your referring to a BACK PRESSURE test where you remove all the spark plugs and put a constant supply of air into each cylinder and see if bubbles appear in the radiator with the radiator cap off.

This IS a very good test to determine blown head gaskets . All you need is just ONE cylinder to produce the bubbles and this confirms that the head gaskets are blown and you will need to remove both cylinder heads, drill out and insert heli-coils in all the head bolt holes in the engine block and replace all the head bolts and naturally install new head gaskets and install the SEALANT PELLETS in the radiator when you install NEW anti-freeze.