1993 Holden Commodore

Hi there,

You will need to do a wet test. This is where a small amount of oil is added to the cylinder just a few squirts from an oil can, this will seal the rings and then do a comp test again, if the comps come up the rings are a problem if not the valves are the problem, do this one cyl at a time, and the rule of thumb is no less the 10% variance from high comp to low comp.

Mark (mhpautos)