cparke

If I want to do a compression test on my V6 30V engine myself, do I need to take all the spark plugs out of both banks before I can test anything? I really only want to compression test bank 1 and would prefer to leave bank 2 alone if I can. Also, is it really safe (for the engine, forgot about my hands) to remove the spark plugs while the engine and cylinder head are hot?

Nate (ETKA+Scumbag)

You have to do it on a warm engine otherwise the numbers aren't accurate.

4Driver4

Better off with a leak down test, but yes, all plugs come out for a proper test.

cparke

I'm not even sure there is a problem.

Leave it to the professionals to do a leakdown diagnosis if there is some evidence of a problem from a home compression test.

VMRSport

You don't have to, but it's easier if you take out all of the spark plugs first. Technically you are suppose to do it while the engine is warm, so it should be fine. That's how I always did mine, so that the pistons, etc are all sealed correctly.

You also want to have the throttle at wide open, while you are doing the comp test.

Don@VelocityMotoring.com