Low compression after rebuild, help.

ONLY for ADVANCED technical discussion about the 240sx!
bentong2k2
Posts: 83
Joined: Sun Mar 26, 2006 2:26 pm
Car: 240sx 1991 KA24DE

Post

i just rebuilt my SOHC w/ DOHC pistons so i know the compression will be alittle lower. I also replaced the headgasket. Right now, all 4 cylinders are at exactly 87 psi so i assume the problem is not w/ the headgasket or piston rings b/c of the exact same compression in the cylinders. Could i have a timming chain problem? I lined up the dot mark on the cam sprocket w/ the silver marking of the chain and i never opened up the front cover so the bottom of the chain could not have moved. Anyone w/ an idea of why my car does not work?

p.s. i hear a clicking sound when the key is in the start position, i dont know if thats normal or not.


i2ice4m3
Posts: 713
Joined: Mon Dec 30, 2002 2:11 pm
Car: COUNTERSTRIKE!

Post

if your battery is bad/low (i'm guessing from the clicking sound) you might not be getting enough power to the starter. Low turning rpms can give low pressure readings. Also, you can only get accurate readings at operating temp

User avatar
TravisD
Posts: 299
Joined: Tue Jun 08, 2004 5:46 pm

Post

Are the rings seated yet? If not, you will get low compression #'s because they don't seal fully right away. What do you mean by "doesn't work"? Does it start and run? If it clicks and won't start, whack the starter with a mallet. If it works after that, buy a new starter.


Return to “240SX Technical Forum”