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Old 05-06-2020, 07:00 PM   #17
RZNT4R
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There is a way to be sure of a head gasket.

What you will need is an compression test gauge with the appropriate adaptor for the fa20's spark plug threads, an air compressor, a big ratchet to turn the engine over by hand from the crank pulley, some other basic tools and lots of patience given the accessibility of the plugs on this engine.

Here is what you will need to do:

- Take all the spark plugs out
- Remove the Schrader valve from the compression tester hose so you can send air into the engine.
- Install the compression test hose into the first cylinder
- Remove the radiator cap and level the fluid so its half way down the filler neck
- Install the air compressor onto the compression test hose, sending high pressure air (ideally 120+ Psi) into the cylinder
- Rotate the engine by hand with your big ratchet on the crank pulley until the pressurized cylinder enters the compression stroke and the valves shut. It will immediately refuse to turn any further.

And now, as you strain against the ratchet to keep the engine from turning backwards, watch the coolant level closely. Hold it for at least 30 seconds. If the coolant level rises or overflows, that's your bad gasket.

Do all 4 cylinders. If none make it throw up coolant, it's highly u likely you've got a bad head gasket.
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