cr125

hi all, i just completed a compression check on my 94 accord 2dr dx. i just want to know if the numbers are good or not. all the numbers are even. and the car has 136,000 miles
cly1=150psi cyl2=150psi cyl3=150psi cyl4=150psi

i was suprised all cyl were the same! are these numbers good? the engine runs strong. let me know. thanks for ur help

Derek128

from haynes

Std 178 psi
Min 135 psi
Max variation between cylinders 28psi

My wet/dry compression test w/ 166700KM (103583 Miles)

------dry-wet
cyl 1 182 190
cyl 2 180 186
cyl 3 180 180
cyl 4 180 187

cr125

are u suppose to hold the throttle wide open when u crank the engine? i didnt hold it open. i hope that didnt effect the readings

Derek128

I don't think so
U won't start ur car like that
its dangerous

do i wet one & see if the rings r worn or so

cr125

if u dont mind me asking, what do u mean by wet or dry? i just took each plug off and but the tester in and cranked it. i didnt take any fuses or anything off. can u please explain. THANKS in advance

Derek128

u did the dry one already

a wet one is adding a little bit of engine oil into each cylinders & then crank it

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by http://autotechrepair.suite101.com/article.cfm/032106 &raquo;</TD></TR><TR><TD CLASS="quote">
from http://autotechrepair.suite101...32106

Why Does an Engine Use Oil?

There are only two ways for oil to get inside the combustion chamber. Oil comes in either through the valve seals or up past the piston rings. It is easy to determine which by doing a wet/dry compression test. Bad valve seals will show no improvement in compression with the wet compression test.

A valve seal seals the valve stem and prevents oil from going through the valve guide and into the combustion chamber. Over time, these seals can wear out and need to be replaced. In most cases this is a relatively easy job, and can be done without removing the cylinder heads.

Piston rings require an engine overhaul to correct. The pistons have to come out, ring lands have to be checked and cleaned, and the cylinder walls have to be inspected for scoring, pitting and roundness. If all is well, the cylinder wall is honed and new piston ring installed. This will correct that cause of oil burning.

Worn out piston rings are indicated when there is a 15% to 20% increase in compression in a wet compression test.</TD></TR></TABLE>

cr125

ok i read and did some research on how to do a compression and i do have to have the throttle wide open my numbers changed drastically
cyl1=190 psi
cyl2=185 psi
cyl3= 185 psi
cyl4= 185 psi


is this about normal? the engine has almost 137,000 miles

joezmam367

i realize this is an old post and hope somebody notices this reply
i did a compression test last night while i was cleaning the intake ports and EGR valve. basically did it to kill time so i didn't waste my beer lol.
either way, the car was cold while i did this and i think that, is where I'm thinking too much on these numbers.

I also left the throttle closed which i realize after some reading was wrong as well. so ill be retesting tonight.

Cyl 1 tested at 150 - im going to count that number as a wet test because i found oil in the gully and will be replacing the seals this weekend, but that was the only wet plug

Cly 2 Dry was 120, wet was 135
Cly 3 dry was 125, wet was 140
cly 4 dry was 120, wet was 140


for my wet test i used a cap full of oil, where as i believe in cyl 1 there was a bit more than that.

ill retest tonight when i get home keeping the throttle open and making sure the car is warm.

ill try to repost new numbers tomorrow.

any input is always appreciated if i seem to be missing something.

GhostAccord

It is hard to give a solid answer with so many variables. Seems like you are on the right track though. I'm sure someone will have more input after you post up the info on your dry and wet with the throttle open and engine up to operating temps. (warm)

backinblue92

iTrader: (1)

If your numbers rise with the wet test, it means the rings are going. Oil helps seal the rings which is why it changes the numbers.

Also cold vs warm, metal expands in heat so the expansion of rings will give you higher numbers.

The numbers are less relevant than variance, however. U want all cylinders close to or less than 10%

Ps- from what I've read in the past, doing the test without throttle wide open only measures vacuum capacity of a cylinder. But I read that online. Lol