So I heard a healthy ls engine has cylinder bore compressions about at 180psi, my ls engine is currently pushing out 120psi in all 4 cylinders... Is it time for a rebuild or is it fine since the cylinders all have the same amount of pressure?

 

did a wet compression test and got the cylinders to 150 psi ><, so i'm thinking it may be the piston rings

 

ya if the compression went up then its your rings, prolly normal wear and tear?

 

make sure the engine is warm when doing your tests.

 

different testers read differently

 

it could be wear and tear, so i may buy a new pair of pistons and rings. Would the cylinder walls be fine?

 

well the wet compression test made a jump from 120 to 150psi, so there are problems with the pistons and or rings; it may as well need to be rehoned. Well seeing as that I was just wondering why would all the cylinder banks be showing such a low pressure, is it likely for all cylinder banks to be like this? Becasue I thought low compressions usually only happen to one or two cylinder banks?

 

did u pull all 4 plugs out?

i remember wanting to kick my engine to the curb when a known-good snap-on compression tester read 95psi.

i then pulled all four plugs and voila 180psi across.

 

as in all 4 ignition coils? yes and the spark plugs, so I had 3 venting cylinder banks while 1 was attached to the gauge. got a reading of 120 on all 4 banks.. =[

 

You will need to hone the cyl walls so the new ring will seat properly.

 

yeah u did it right, one plugged in and 3 venting...sorry for the bad news.

 

yeah... =[
time fore a rebuild!