Notices
Forced Induction Turbochargers and Superchargers..Got Boost?

how is compression check done

Thread Tools
 
Search this Thread
 
Old Feb 15, 2009 | 12:15 PM
  #1  
andyisphat2004's Avatar
andyisphat2004
Thread Starter
Registered User
iTrader: (1)
 
Joined: Mar 2003
Posts: 985
Likes: 0
From: Fairfax, VA
Default how is compression check done

I am selling my car and the buyer has a buddy who will do a compression check. How is this done? I want to make sure that I am getting legit results.

Thanks
Reply
Old Feb 15, 2009 | 12:16 PM
  #2  
Spork's Avatar
Spork
Registered User
iTrader: (6)
 
Joined: May 2007
Posts: 27,592
Likes: 6
From: MN
Default

1. Disable ignition.
2. Remove spark plugs.
3. Thread in compression gauge.
4. Turn engine over 5 times.
5. Check gauge and record results.
6. Repeat for other cylinders.
Reply
Old Feb 15, 2009 | 12:18 PM
  #3  
andyisphat2004's Avatar
andyisphat2004
Thread Starter
Registered User
iTrader: (1)
 
Joined: Mar 2003
Posts: 985
Likes: 0
From: Fairfax, VA
Default

I havent changed my plugs since i installed the TN kit. It is a PIA with turbo isnt it?
Reply
Old Feb 15, 2009 | 12:23 PM
  #4  
andyisphat2004's Avatar
andyisphat2004
Thread Starter
Registered User
iTrader: (1)
 
Joined: Mar 2003
Posts: 985
Likes: 0
From: Fairfax, VA
Default

looks like you have to remove the charge pipe to get to the plugs.
Reply
Old Feb 15, 2009 | 01:43 PM
  #5  
QuadCam's Avatar
QuadCam
Registered User
iTrader: (8)
 
Joined: Apr 2003
Posts: 3,869
Likes: 4
From: Vero Beach, Florida
Default

Originally Posted by Spork
1. Disable ignition.
2. Remove spark plugs.
3. Thread in compression gauge.
4. Turn engine over 5 times.
5. Check gauge and record results.
6. Repeat for other cylinders.

you forgot a couple steps........

1) disable injectors (unplug injector harness) and pull the fuse on the fuel pump.

2) open throttle blade while cranking (i prefer to pull the intake manifold for this job. it makes getting quick access to the plugs a lot easier.)
Reply
Old Feb 15, 2009 | 01:47 PM
  #6  
andyisphat2004's Avatar
andyisphat2004
Thread Starter
Registered User
iTrader: (1)
 
Joined: Mar 2003
Posts: 985
Likes: 0
From: Fairfax, VA
Default

what is estimated time to complete?
Reply
Old Feb 15, 2009 | 02:05 PM
  #7  
Glex25's Avatar
Glex25
Registered User
iTrader: (11)
 
Joined: May 2005
Posts: 1,301
Likes: 0
From: New Jersey
Default

Originally Posted by QuadCam
you forgot a couple steps........

1) disable injectors (unplug injector harness) and pull the fuse on the fuel pump.

2) open throttle blade while cranking (i prefer to pull the intake manifold for this job. it makes getting quick access to the plugs a lot easier.)
You mean mash the gas pedal while cranking.
Touching the throttle blade will take the throttle body out of calibration.

Hmmm good to know that you an do a compression check
with the plenum off that is one of the things I was wondering
since I'm about to do a few things and figured I would do a
compression check while in there
Reply
Old Feb 15, 2009 | 02:36 PM
  #8  
Sharif@Forged's Avatar
Sharif@Forged
Sponsor
Forged Performance
iTrader: (92)
 
Joined: Dec 2003
Posts: 13,733
Likes: 1
From: Marietta, GA
Default

Originally Posted by QuadCam
you forgot a couple steps........

1) disable injectors (unplug injector harness) and pull the fuse on the fuel pump.

2) open throttle blade while cranking (i prefer to pull the intake manifold for this job. it makes getting quick access to the plugs a lot easier.)

Yup!
Reply
Old Feb 15, 2009 | 05:27 PM
  #9  
JETPILOT's Avatar
JETPILOT
New Member
iTrader: (51)
 
Joined: Feb 2004
Posts: 6,319
Likes: 2
From: Vero Beach, FL
Default

Compression check won't tell you much. I did a compression check on my motor and it came up normal. Then I did a leakdown test on it and it showed high leakdown on 2 cylinders. Just do a leakdown check.

P.S. Don't listen to Quadcam about taking off the intake manifold to get to the plugs for a compression check. You can get to them just fine without taking it off and the pain in the *** that goes with it like stripping intake plenum threads, and a possible manifold leak. He looks for every opportunity to take off his intake manifold. Why? Boredom is my guess I'm going to hear about this soon. Should be getting a phone call in 5 minutes!

Get the leakdown done!
Reply
Old Feb 16, 2009 | 06:07 AM
  #10  
QuadCam's Avatar
QuadCam
Registered User
iTrader: (8)
 
Joined: Apr 2003
Posts: 3,869
Likes: 4
From: Vero Beach, Florida
Default

Originally Posted by JETPILOT
Compression check won't tell you much. I did a compression check on my motor and it came up normal. Then I did a leakdown test on it and it showed high leakdown on 2 cylinders. Just do a leakdown check.

P.S. Don't listen to Quadcam about taking off the intake manifold to get to the plugs for a compression check. You can get to them just fine without taking it off and the pain in the *** that goes with it like stripping intake plenum threads, and a possible manifold leak. He looks for every opportunity to take off his intake manifold. Why? Boredom is my guess I'm going to hear about this soon. Should be getting a phone call in 5 minutes!

Get the leakdown done!

WTF!!!! some of us have never stripped a manifold bolt!!! that...and I love to use my torque wrench......I have to feel like I am getting my money's worth out of that damn Snap-On wrench!! seriously though.....I still prefer to pull the manifold. using power tools, the manifold is off in a very short amount of time.......plus, it gives you easy access to all the bolts and no chance of dropping one. the nissan gaskets are reusable, the buying gaskets is not an issue either.
Reply
Old Feb 16, 2009 | 06:18 AM
  #11  
chopperman's Avatar
chopperman
Registered User
iTrader: (9)
 
Joined: Jan 2007
Posts: 1,313
Likes: 1
From: Long Island, NY
Default

Here is a tread that I created a month or two ago.
https://my350z.com/forum/forced-indu...own-tests.html
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
MM'08_350Z
VQ35HR
225
Apr 22, 2021 09:42 PM
Colombo
Forced Induction
35
Nov 9, 2020 10:27 AM
Sleeper_Z
Forced Induction
3
Sep 30, 2015 10:25 AM




All times are GMT -8. The time now is 07:08 PM.