Top Causes of Low Engine Compression

two many things it can be compressor rings, it can be valves, It can be air escaping out of your combustion chamber through the plugs holes or injector holes. Check if seals on injectors (Orings) are good and the washers on plugs if it seals. 

It can be your timing or timing chain /belt. Take all the plugs out and put a little oil in each cylinder and put the plugs back and turn the engine crankshaft and listening if you can hear compression than you know your compression rings are worn out. Or check with your compression tester but if you check with that you have to start with the key but disconnect your coil so that the car must not start you only wanna check compression. Did the car drive before or you did work on the engine?

• Change the Rings, it will compress.


• Worn piston rings or crack cylinder block


• Worn out piston rings worn out cylinder leaky valves loose cylinder head


• Check piston ring & check inlet valve exhaust valve how to operate


• Make sure the timing chain ain't broken and or make sure the piston is turning and crank not broken


• The main problem is compression rings, worn out or cracked cylinders. And maybe the valve timing problem


• Check tappet clearance. OK, then valve leaking. Cylinder bore worn-out. Piston rings worn-out


• It cud be that the spaces between the piston rings and cylinder bore (liners) are not up to the mark probably due to rust.


• maybe the valve doesn’t allow the air-fuel mixture to enter the combustion chamber so the piston will compress nothing