[IHateHacks]

Not to sound like a d!ck but a compression test will not determine if you have a blown head gasket. My compression tested at 180psi across the board with no more than 7psi difference between them yet I still had a BHG. A block test is the only thing that can 100% guarantee that your head gasket is good or not. My block test turned from blue to green. Plus its alot simpler to do a block test, all you have to do is take the radiator cap off and drain a few quarts of coolant via the radiator drain plug. Compression test, you have to remove all the spark plugs which means removing all of the stuff on top of the spark plugs, and more than likely your spark plugs will be covered in a couple inches of oil so you will have to deal with that mess and then disable the fuel pump. Because if fuel is being sprayed into the combustion chamber while you are testing compression, it will throw off the readings.

On the intake manifold side there are 2 coolant lines under the throttle body. 1 goes from the Throttle body to the water by pass pipe and 1 goes from the lower intake manifold to the ISC valve. Then there is one that goes from the throttle body to the ISC valve. On the exhaust manifold side there's a coolant line that goes from the bottom of the water outlet housing to the water by pass pipe and theres one that goes from the water by pass pipe to the heater union. Then there are the 2 rubber turbo lines that like to leak if they are original 20 year old hoses. Then in the back of the engine the heater core outlet is on the intake manifold side and attaches to (yep you guessed it) the water by pass pipe and the heater core inlet goes from the heater union to the valve on the firewall to the heater core.