engine experts enter for a compression question
Thread Starter
Drifting
Joined: Nov 2005
Posts: 1,795
Likes: 1
engine experts enter for a compression question
background
started smoking off idle out of left bank pretty bad last week
no noticable smoke at speed/higher rpm.
pulled the plugs on drivers side and found #5 oil fouled.
a little while ago i heated the car to operating temp,blocked
throttle wide open and ran a compression check.
the manual says crank over 4 times, says if first one is low
then a bad ring is the problem.
my problem is the book doesnt say what is considered low.
my results are 1st stroke 110psi
2nd 130psi
3rd 150psi
4th 170psi
and stayed at 170 for every crank there after
it looks as though the compression builds uniformly as there
was 20psi each stroke after the initial 110 to the peak of 170.
in case your wondering i have not tested the other cylinders yet.
any and all answers would be appreciated
started smoking off idle out of left bank pretty bad last week
no noticable smoke at speed/higher rpm.
pulled the plugs on drivers side and found #5 oil fouled.
a little while ago i heated the car to operating temp,blocked
throttle wide open and ran a compression check.
the manual says crank over 4 times, says if first one is low
then a bad ring is the problem.
my problem is the book doesnt say what is considered low.
my results are 1st stroke 110psi
2nd 130psi
3rd 150psi
4th 170psi
and stayed at 170 for every crank there after
it looks as though the compression builds uniformly as there
was 20psi each stroke after the initial 110 to the peak of 170.
in case your wondering i have not tested the other cylinders yet.
any and all answers would be appreciated
Burning Brakes
Joined: May 2007
Posts: 945
Likes: 0
From: Ventura California
Your compression check numbers are not looking bad really. The main thing is to compare readings between cylinders and to do a leakdown test. The symptom you are describing seems more like a leaking valve stem seal to me. Just my opinion but I'm sure others will chime in.
Burning Brakes
Joined: May 2004
Posts: 1,100
Likes: 3
From: belle plaine ks
Thread Starter
Drifting
Joined: Nov 2005
Posts: 1,795
Likes: 1
i will probably wait until this weekend to test the other 7 cylinders and see what i have compression wise.
leak down test i wont be able to do at this time
because i dont own the tool for it unless auto zone rents one.
i will post the other readings once i have them
