Compression Test on my 318, not good

Next, do another compression test "wet" and see if it makes a difference.

A "wet" compression test will let you know if it is in the rings or valves. Take an oil squirt can and put 2-3 "squirts" of oil in each cylinder just before you do the compression test. See if there is any difference between the "wet" and "dry" tests (the dry test is without oil).

If you get better results after squirting the oil in than without, then you may have a ring/blow by issue.


After the wet and dry compression test, perform a leak down test if you have a leak down tester. This will also let you know if it is in the rings (leaking/hissing in the crank case), or intake valve (hiss/leaking sound through the intake/carb), or exhaust valve (hissing/leak through the tailpipe).

If it turns out to be a ring issue (which it may be with your initial results), then I would recommend installing new rings and possibly doing a quick hone with a "ball hone" when you do. You can get ball hones at NAPA.