Relax
Well-known member
For the cylinders with low compression, add some oil to them (through the spark plug hole) then rerun the compression test to see if it increases. If it does, it's the rings. If it doesn't, then it's the valves. Or possibly the head gasket - you can tell if there are bubbles in the cooling system as you perform the compression test, or if it's really bad, you will see the coolant overflow bottle filling up when it runs.