Hey
I just ran a compression test. Here are the numbers, 210-200-105-215.
I poured engine oil into the low cylinder and it went up to 275. What does this mean?

probably bad rings in that cylinder....

Well, the 105 in the dry test is pretty low. The 275 in the wet test means that you put too much oil in the cylinder. I broke a compression guage that way once. You don't want to put too much oil in the cylinder for a leak down test - a cap full should be plenty.

Run the car again. Warm it up to normal operating temp and retest it. The dry numbers should be about the same. If the leakdown(cap full) brings cyl 3 up to around where the others are then that would indicate that the ring is worn on that cyl.


95 Eclipse RS : 5 speed
Jeep TB writeup - http://www.dimensia.com:81/jimbo/JeepTBfor2gnt.html

Now when I restart the car, the check engine light is on. I did the little code thing and its throwing code 43 and 42. Is this because I had the relays disconected before or what? I'm getting worried now... I'm dont know if I should let it run or not.

>Now when I restart the car, the check engine light is on. I
>did the little code thing and its throwing code 43 and 42. Is
>this because I had the relays disconected before or what?

Yeah. Give it a day or two, or just reset the ecu and they'll go away.

Ran test again in #3 cylinder after letting car run for 10mins, it showed 225. I didn't pour any oil into it this time around. Could it be that I had no problem and something was hooked up wrong? Or do I need to replace a gasket somewhere? Check engine light is still on, key dance shows code 42 and 43. Are these codes normal after a compression test? I hope I didn't mess anything up or my engine is blown :(

Just disconnect the neg batt cable for one second then reconnect it. That will erase your ECU codes. Sounds like you just got a bad reading the first time around.

I hope so. I think running it for a week then checking it again is the next step from here. I'll make sure the holes are clean and no dirt preventing a good seal. The other readings were great though. Isn't it strange that it would be that low in one cylinder and great numbers in the rest?

i had essentially the same thing happen to me......made me think twice about going turbo. i got my compression tested and got 180, 75, 180, 180. then they tested cylinder two again and got it to go to 180 consistently(4 times). i'm now rethinking whether i should go body kit or hrc stage 1.......i'm leaning towards the turbo right now. but that one cylinder is still worrying me a little. anybody think i should just go for the turbo and quit my whining???

sounds like you had it hooked up wrong on that one cylinder. Get the turbo, if it blows, then you'll have a good excuse to rebuild and run higher boost )( I'm trying to get stage 1 or 2 within the next month or so. I REALLY didn't want to rebuild right now if I didn't have to. I had planned to get stage2 then rebuild after 6months or so. But..we'll see...

i wish i had done it myself. but instead i let satan do it while i had it in for an oil change. but i agree, they probably didn't hook it up right.

Bump. Anybody with any other input would be apprechiated.

Just check it again in a week. If the number is still high, count it up to a bad test.

Satan is the worst...I've never done a comp. test before and I'm curious as to how much I should pay to get one done, as I have no idea what i'm doign on that one...

matt

its pretty easy, just check corbins write up

thanks I appreciate it

>i had essentially the same thing happen to me......made me
>think twice about going turbo. i got my compression tested
>and got 180, 75, 180, 180. then they tested cylinder two
>again and got it to go to 180 consistently(4 times). i'm now
>rethinking whether i should go body kit or hrc stage
>1.......i'm leaning towards the turbo right now. but that one
>cylinder is still worrying me a little. anybody think i
>should just go for the turbo and quit my whining???

when I first installed my turbo those where the numbers I got the thing lasted for about a year :thumbsup but towards the end of its life the LAG was horrible, it felt like I was punishing the car like it was sick with some kinda disease I had to clutch kick it just to boost faster. :(