Patrol 4x4 - Nissan Patrol Forum banner

1 - 5 of 5 Posts

·
Registered
nissan
Joined
·
416 Posts
Discussion Starter #1
How much compression should ea cylinder have for a 4.2 turbo Gu, just curious and want to test mine
 

·
Registered
Joined
·
775 Posts
We like to see a minimum of all cylinders to be 400 psi, cranked over 10 times no fuel going into the cylinder while compression testing. Anything lower and its showing signs of age.


Andy
 

·
Registered
nissan
Joined
·
416 Posts
Discussion Starter #4
thanks guys, and if its lower, then should i be looking at putting some rings through her or not.
would u have to hone ea cylinder or can a set of rings just be put on. still a big job i know.
i just had car running and took oil filler cap off and there was only very minimal amount of air blowing on my hand, and no oil blowing out of it.
 

·
Registered
nissan
Joined
·
116 Posts
if your going to pull it down just to do rings you may aswell let it run for an extra few months as long as its not burning oil etc and then do a proper rebuild while its fully apart. if its well looked after itll be pretty good mine has 450k on it runs 18psi daily since 360k i drive 800min klms a week and my compression is around 580psi in each, minimum spdc is 400-430 psi the main thinkg to look for is the diference between each cylinder also when your doing your test make sure you test drive first (no oil added) then do them all again and put a bit of oil in each cylinder if there is a huge increase in psi the rings are buggered if still steady but low then you have some issues and from memory i think its 50psi diffrence allowed between cylinders
 
1 - 5 of 5 Posts
Top