General For General 240sx/Silvia (s-chassis) discussions.

Compression numbers

Thread Tools
 
Search this Thread
 
Old Nov 17, 2007 | 03:34 PM
  #1  
Sevarg710X's Avatar
Thread Starter
Registered User
 
Joined: Apr 2005
Posts: 138
From: Baton Rouge , Louisiana
Compression numbers

Ok it's a 91 with 98,xxx . did a compression test and numbers were 120,130,130,140 . Are these numbers okay ?
Old Nov 17, 2007 | 04:57 PM
  #2  
MS!3's Avatar
Contributing Member
iTrader: (1)
 
Joined: Apr 2006
Posts: 2,069
From: USA
sorry man, might be time for a rebuild. should be reading at least 160 or so.
Old Nov 17, 2007 | 09:57 PM
  #3  
Sevarg710X's Avatar
Thread Starter
Registered User
 
Joined: Apr 2005
Posts: 138
From: Baton Rouge , Louisiana
Seriously ? I thought they were okay as long as they were within like 10% of eachother
Old Nov 18, 2007 | 12:36 AM
  #4  
Biggamehit's Avatar
Contributing Member
iTrader: (2)
 
Joined: Aug 2004
Posts: 5,091
From: Misawa, Japan
na bro... that 10 over or under the max 179 and lowest 151

that motor is way gone bro

so if it was like 175 175 175 180 that would be ok

Last edited by Biggamehit; Nov 18, 2007 at 12:46 AM.
Old Nov 18, 2007 | 10:05 AM
  #5  
KFL's Avatar
KFL
Registered User
 
Joined: Dec 2003
Posts: 90
From: Central New Jersey
Did you properly do the test..ie warm up car, and hold gas open while cranking.. sometimes people forget 1 or the other..
Old Nov 18, 2007 | 10:27 AM
  #6  
slos14's Avatar
Registered User
 
Joined: May 2004
Posts: 38
From: st.louis mo
the motor only has 98k an it has that low of comp . **** man my car has 180k on it an its at 180 in all 4 . thats nutz
Old Nov 18, 2007 | 10:39 AM
  #7  
Initial Daniel's Avatar
Contributing Member
 
Joined: Oct 2004
Posts: 886
From: Woodbridge
Yeah, mine was 175 ---> 180.

...and the dude who bought it still blew the motor. LOL.
Old Nov 18, 2007 | 12:38 PM
  #8  
Sevarg710X's Avatar
Thread Starter
Registered User
 
Joined: Apr 2005
Posts: 138
From: Baton Rouge , Louisiana
I didn't hold the gas open while cranking . I'll try again and repost .
Old Nov 19, 2007 | 06:58 AM
  #9  
nissandrift's Avatar
Registered User
 
Joined: Feb 2004
Posts: 114
From: Raleigh, NC
If your numbers are still close, after doing it at WOT... you may want to try another compression tester. The gauge may not be calibrated, and if thats the case you may be fine.
Old Nov 19, 2007 | 08:47 AM
  #10  
BigVinnie's Avatar
Registered User
iTrader: (2)
 
Joined: Nov 2004
Posts: 2,502
From: Walnut Creek
Make sure that oil was well circulated as well through out each cylinder.
Heavier weight can bring those compression numbers up.
Old Nov 19, 2007 | 09:11 AM
  #11  
nissandrift's Avatar
Registered User
 
Joined: Feb 2004
Posts: 114
From: Raleigh, NC
On that note if you pour a very little amount of oil down each cylinder when testing you can see if the rings are your problem... if the numbers go way up.
Old Nov 19, 2007 | 09:21 AM
  #12  
Bumnah's Avatar
Registered User
 
Joined: Dec 2006
Posts: 434
From: VA
just for to put the information out there.
the 170+ compression numbers are for cars that can turn over on their own.

if you were doing a compression check by hand cranking the numbers will not be that high. while hand cranking my old ka24de and doing a compression check, it was hitting 110-120 (if i remember correctly) per cylinder. i did each cylinder twice, and got consistent numbers every time. you can also hear it sucking in air from the open spark plug holes while rotating by hand. another thing to look for when checking out a motor to see how it is doing.
Old Nov 20, 2007 | 04:54 PM
  #13  
Sevarg710X's Avatar
Thread Starter
Registered User
 
Joined: Apr 2005
Posts: 138
From: Baton Rouge , Louisiana
Haven't got around to doing it yet . Been workin late .

Big Vin : I use 10w40

nissadrift : how much is a little ?
Old Nov 20, 2007 | 07:37 PM
  #14  
nissandrift's Avatar
Registered User
 
Joined: Feb 2004
Posts: 114
From: Raleigh, NC
I did about a cap full, but fyi the car will smoke starting up for a bit after.
Old Nov 20, 2007 | 08:14 PM
  #15  
BigVinnie's Avatar
Registered User
iTrader: (2)
 
Joined: Nov 2004
Posts: 2,502
From: Walnut Creek
10w40 is perfect



All times are GMT -7. The time now is 05:34 AM.