PDA

View Full Version : My compression test results make me want to cry :(


Chuck
12-01-2005, 10:54 AM
Cyl 1 -- 137 psi (cold)

Cyl 2 -- 126 psi (still cold)

Cyl 3 -- 165 psi (normal, but cranked over a few times.. making it warmer)

Cyl 4 -- 157 psi (low, but nominal, and still in spec)

Im probably going to try again tonight, when i get home from school.. and let the car run for a while, and warm up, then test it again..

hopefully my numbers will get higher when its hotter (which it should, cause metal expands)

rival240
12-01-2005, 11:08 AM
doing it cold gives most acurate results doing it warm yes the metal expands so thats what importers do to get better reading when selling you a motor...

Chuck
12-01-2005, 11:09 AM
yea, im trying to decide if i should just swap the head (my valve guides are leaking oil) but now a long block is looking more likely

eliterit
12-01-2005, 12:39 PM
im pretty sure the fsm says to warm up the engine first before doing compression test

Chuck
12-01-2005, 12:40 PM
yea, but if i had 180 psi in each cyl when its cold.. id be much more happy..

Chuck
12-01-2005, 12:42 PM
http://img207.imageshack.us/img207/8027/compression1hn.jpg

crzycav86
12-01-2005, 12:58 PM
Make sure it's held at wot. and yes, warm up the motor :)

Chuck
12-01-2005, 01:39 PM
oh... wot... damn, didnt even think about that...

i just did it warmed up (2-3 notches above C)

came out at

1- 150 psi
2- 165 psi
3- 178 psi
4- 177 psi

not.. TOO bad.. but pretty un-even for my tastes.. can you guys say " Time to blow up this KA so i have an excuse to get a new one" ;) lol

drz
12-01-2005, 03:53 PM
those numbers are similar to a compression test i did on my na sr20 when it had 150xxx miles. it now has 215 and still runs strong. i say it'll last


oops. this is eliterit btw, not drz

dookie
12-04-2005, 04:26 PM
well, youre out of spec, thats for sure, you have a greater than 14psi difference between all cylinders and that #1 is out of spec. To figure out whats wrong, put some oil in the spark plug hole and retest that #1 cyl, if you get good compression, your rings are cracked. If you're still at 150, you got bad valve seals or something else related to the valvetrain.

Nismo_Freak
12-04-2005, 05:03 PM
Run a leakdown test, compression testing is too pass:fail.

Besides, pulling the engine, and re-slugging it is easy.

NAASBC355
01-08-2006, 12:14 AM
those numbers could reflect carbon build up which is not really a big deal i don't see any reason to worry, if its a blown head gasket usually two right next to each other will be low becaus they will share, if its a cracked ring the ring will loose tension and the number will be pretty low burned valve seat or valve will have almost no compression at all. Those numbers look ok.

Ball_Boy_Gordon
01-09-2006, 01:31 PM
Kids, I didn't know that you had bad compression. What the hell?

AAriz82
01-09-2006, 01:42 PM
my motor is for sale

NoShoesDrew
01-09-2006, 01:44 PM
Amir dont sell your motor its mine ok i will give you the money this weekend!!!! call my celly!!!

AAriz82
01-09-2006, 01:49 PM
ok

NAASBC355
01-09-2006, 01:51 PM
valve seats not seals... the number wouldn't be that high usually if its a valve train thing the numbers are real low its probably more likely to be that the head gasket is not holding compression or that the cylinders are that wore out and those guides that are leaking are boosting compression already... don't put a whole lot of oil in the plug hole if you plan to do that test just a little will do i'd say a t spoon at the very most.