You need a compression tester (A gauge that has a rubber end or threaded fitting that fits into the spark plug holes)
Start with a fully charged battery.
Remove all spark plugs.
Hold accelerator fully open.
Install compression tester in one hole at a time, crank engine and compare results.
Highest and lowest should be within 20% of each other.
DRY TEST:
A dry compression test will tell you the overall state of health of the rings/block sealing.
WET TEST:
By adding a squirt of oil into the cylinder before checking compression will seal any tiny gaps in any rings/block. If the compression increases significantly, it would indicate bad rings or scored block cylinder walls.
Nov 14, 2008 at 12:34 AM
