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Forum namePerformance/Engine
Topic subjectcompression
Topic URLhttps://forums.2gnt.com/dcboard.php?az=show_topic&forum=i5&topic_id=103268
103268, compression
Posted by barza21, Mar-01-07 05:08 AM
whats up dudes, i just took a compression test a little while ago and it came out like this: cyl1= 150, cyl2=120, cyl 3= 150, and finally cyl 4= 150, my car has 95,xxx miles on it and its a 1999 gs. but my question is: those this compression seem right to u guys?. because i was reading and a dude that has 145,xxx on his car got 200 across the 4 cyl.
thanks.
103269, RE: compression
Posted by Slo2g, Mar-01-07 05:23 AM
Your numbers are low. Do a leak down test to see if the rings are toast. Do the compression test a couple of times though to make sure you get around the same numbers. They are normally around 185-200. They should be within 15% of each other also.
103270, RE: compression
Posted by cougar694u, Mar-01-07 06:41 AM
Did you do it at WOT? And was the motor warm or cold?
103271, RE: compression
Posted by thedawg, Mar-01-07 07:30 AM
Either your compression tester is broken or you're doing the test wrong.

Crank at WOT until the needle stops moving up.
103274, RE: compression
Posted by barza21, Mar-01-07 09:23 AM
when i did the test i let the engine cool down for about 45min to 60min. so do u guys thing it could be the wrings? and what is WOT, im not really good with acronims. im planing on a rebuild of the whole block, so it can handle some decent boost, but it got me worried (the compression). yes i let the needle go till it didnt go anymore, (i counted eight cycles, some people count 4.) when making it go. but the needle didnt want ot go anymore after it hit the 150 line, so i think im screwed till i rebuild the engine.
103275, RE: compression
Posted by barza21, Mar-01-07 09:24 AM
please pardon my grammar in the previous post, i didnt double read it.
103276, RE: compression
Posted by Nightfall, Mar-01-07 10:03 AM
WOT = wide open throttle

This is your homework, pop quiz tomorrow lol...

http://www.2gnt.com/nuke/modules.php?name=Sections&op=viewarticle&artid=4
103279, RE: compression
Posted by barza21, Mar-01-07 04:14 PM
is there anything u cant find in 2gnt? maybe i should search on how to get along with my brother. i will repeat the test as soon as i can, no i didnt do it at WOT, probobly by the end of the week i will do it. ill keep u guys updated.

thanks for the replies.
103286, RE: compression
Posted by Chamuko, Mar-02-07 06:41 AM
You need the throttle open so that you can pull in air to compress. If not you are trying to pull it through a 1/2" opening. Usually only takes 2 maybe 3 compression strokes.

103291, RE: compression
Posted by bullettdsm, Mar-02-07 08:01 AM
Originally posted by barza21
maybe i should search on how to get along with my brother.

Put his nuts in a vise and he'll whatever you want. Problem solved.

You don't even need to search for that. No thanks necessary.

103294, RE: compression
Posted by RoninEclipse2G, Mar-02-07 09:30 AM
it's an easy mistake to forget WOT I did my first time, my engine pulls 185-190 across the board which is normal for colorado thin air, but when I forgot to hold the throttle open I was getting 140-145
103330, RE: compression
Posted by barza21, Mar-03-07 12:31 PM
i hope u guys r right and i did the test wrong. thanks for the help.
103351, RE: compression
Posted by talon749, Mar-06-07 09:03 AM
what tester are you using...I used a Autozone loan a tool one and it was a piece of shit...we did the test correctly and my numbers were really low, like in the 90's....I went out and bought one from sears it was like like 195's after...reallllly big change, I don't even think the car would run on 90's
103352, RE: compression
Posted by thedawg, Mar-06-07 09:21 AM
It will :)

195-40-110-180 or so works fine, as long as you don't mind having about 20hp and metal chips in your oil ;)
103410, RE: compression
Posted by DarkOne, Mar-09-07 07:40 AM
Originally posted by barza21
is there anything u cant find in 2gnt?


Nope! :)

Originally posted by barza21
maybe i should search on how to get along with my brother.


The answer, invariably, would be "Kill him."