Recently did a compression test on my JDM b18c.

Cyl 1 - 210 PSI
Cyl 2 - 90 PSI
Cyl 3 - 60 PSI
Cyl 4 - 62 PSI

These are cold results. I haven't tested it with a warm motor. I have no clue what could be going on. I even did the half cap of oil in the cylinder. There was about a 25-30 PSI increase across the board. I bought it from a reputable online motor dealer 2 years ago. I just haven't had the motor running until recently. Any ideas?

 

GLWT

 

The only truly accurate compression test, is when the engine is at operating temperature. Those numbers are all over the board, but i wouldn't dwell on them just yet, try and get it running first and go from there. Also make sure that you are cranking for the same amount of time on each cylinder, you will have more accurate results.

 

^^THIS^^

If you still get those kinds of numbers, I'd say that's not good.

 

its just weird that every piston has lower compression as he goes down the list. You should run it on a hot motor. Are you sure that your tester is ok? Because it doesnt make sense to have 1 really strong piston and then 3 dead ones.

 

holy crap, barrow someones tester and do it on a warm engine.
but those numbers are no good at all.

 

Wow, looks like a blown head gasket.

 

The tester is brand new. After cyl 4, I went back and did cyl 1. Same results. I'll start it up, and get it to operating temp, then try again. I also had oil and white smoke coming out of the catch cans. I'm leaning towards the idea of shot rings. I just cant understand why Cyl 1 is so healthy. Thats what makes me lean towards head gasket.

 

probably is a HG then, because it doesnt make sense for 1 piston to be so healthy.

 

Where did you buy it from and how long has it been in?

 

if you see white smoke then it verywell could be a blown head gasket. def look into that man is it overheating?

 

I'm not going to throw them under the bus, but lets say that its probably the first online motor company you would think of. I bought back in April of 2008, installed it in Aug of 2008, but I never got it running until Nov, 09. So, I kind of screwed myself. Oh well. Live and learn.

The white smoke isnt coming out of the exhaust. Just out of the catch cans. Its not overheating, but at sometimes the temp will peak, then drop back down. Maybe air pockets working through the system. Who knows.

I'm just going to replace the HG and see where it takes me. If not, then its time for a build. :-D

Thanks for the help

 

valve seals or blow back from burnt rings