compression results, what does it mean?

[babyjesus]

had my car tested today(95 ka24de, apprx 180k), i understant i should have anywhere from 150-170 or so across all cylinders with plus or minus around 5 variance between each. my test results were as follows

c1=105
c2=98
c3=100
c4=100

it looks like its wearing relatively evenly, but does it mean my motor is running low on life because my numbers are so low? also, i was planning on boosting this motor, does that sound safe, running no more than 9 pnds?

[jspaeth]

running low on life because my numbers are so low? also, i was planning on boosting this motor, does that sound safe, running no more than 9 pnds?

:duh:

There is clearly something VERY wrong with the motor, or you didn't do the compression test correctly.

Either way, don't spend any money on that motor unless it is to fix it.

[Mister.E]

that is really low man. i agree with the guy above.

[babyjesus]

the car was tested by an autp tech teacher, so the test had to have been done properly, or at least thats what i assume....im not burning any oil and motor still has plenty of power, not sluggish at all , no smoke, never over heats, feels like the motor is truly still strong

[SleepR 240sx]

Well if you really think the motor still feels strong. Go have someone else do another test on it or do one yourself.

But if that is your correct results then you should not even think about boosting that motor. It won't be able to handle it.

Best bet is if you don't have money to rebuild now then don't thrash on it and just drive nice for a while until you do have the money.

[babyjesus]

thats exactly what i was already thinking, i know better than to boost now with those results, i have money to put another motor, but a ka wouldnt be the route i wanted to go, sr20det would be ideal, but i don't have enough for that , sr20de would be more in my range....but for now ima have it tested again and cool it for a while...thanks for the help

[lbreevesii]

yikes! thats stupid low. I think FSM says 159 minimum. My 215k motor gave me 190

[babyjesus]

had it tested again this morning at a shop, ran about 140 across the board!!!!don't know what the other dude was doing wrong but i feel alot better now!!!!

[steve shadows]

had my car tested today(95 ka24de, apprx 180k), i understant i should have anywhere from 150-170 or so across all cylinders with plus or minus around 5 variance between each. my test results were as follows

c1=105
c2=98
c3=100
c4=100

it looks like its wearing relatively evenly, but does it mean my motor is running low on life because my numbers are so low? also, i was planning on boosting this motor, does that sound safe, running no more than 9 pnds?


I suggest you re-do the test-

Make sure to crank 8-10 cranks per cylinder.
Make sure to pin the throttle plate open FULL THROTTLE
Remove the fuel pump fuse from the fuse box, unplug the ignitor from the dist

[Mister.E]

140 is sounding a lot better than you previous results. i dont think the first guy was doing it right at all.

[spooled240]

yeah 90 psi is cracked ringlands status lol

and there's no way a 215k mile motor cranked out 190 psi, a brand new ka according to the FSM has 179 psi

[projectRDM]

yeah 90 psi is cracked ringlands status lol

and there's no way a 215k mile motor cranked out 190 psi, a brand new ka according to the FSM has 179 psi

Carbon buildup. I tested a 180k mile auto car and saw 205-210 across it.

[TachPHD]

I suggest you re-do the test-

Make sure to crank 8-10 cranks per cylinder.
Make sure to pin the throttle plate open FULL THROTTLE
Remove the fuel pump fuse from the fuse box, unplug the ignitor from the dist

The teacher probably forgot to open full throttle during the test.

[Pacman]

Don't forget to have a battery charger hooked to it so the battery doesn't get low. That could have been the reason for low readings, not spinning fast enough. No oil
was added on the second test to increase compression was there.

[babyjesus]

^^^no i watched this time around and made sure

[clain]

When doing the compression test, do you take out all spark plugs, or just the one on the cylinder you are testing?