Notices

Compression test on cylinders when cold?

Thread Tools
 
Search this Thread
 
Old 15 April 2012, 09:23 AM
  #1  
swisstonihasher
Scooby Regular
Thread Starter
 
swisstonihasher's Avatar
 
Join Date: Jun 2006
Location: South West
Posts: 1,568
Likes: 0
Received 0 Likes on 0 Posts
Question Compression test on cylinders when cold?

Hey all,

Can you run a comp test on all cylinders when cold? I'm just about to get a gunson tester but cannot run the car to warm her up because currently without ecu (in for mods). Would the reading be lower but should be consistent across bores?

Oh, forged pistons, might make a difference to above answer
Old 15 April 2012, 09:52 AM
  #2  
LegacySTi
Scooby Regular
iTrader: (13)
 
LegacySTi's Avatar
 
Join Date: Sep 2005
Location: Dublin, Eire
Posts: 2,785
Likes: 0
Received 0 Likes on 0 Posts
Default

answer is idealy needs to be warm.

you may get inconsistencies accross the cylinders.

But if you have a serious issue then will show up hot or cold.

what are your reasons to want to do it?
Old 15 April 2012, 10:45 AM
  #3  
swisstonihasher
Scooby Regular
Thread Starter
 
swisstonihasher's Avatar
 
Join Date: Jun 2006
Location: South West
Posts: 1,568
Likes: 0
Received 0 Likes on 0 Posts
Default

Hmm, in that case I think I'll check it cold and warm, then record results. Warm will be a few weeks away though.
Well, I have blue smoke on startup sometimes, once a rather large cloud but that's when she wouldn't start first time. It's prob me just being worried over nothing but I've read so many issues with 2.5's and ringland failures...
I've got a mini camera as well to check bore condition which I'll do on monday once I borrow a work laptop.

Last tune I had 1.8 bar peak and 1.7 held and she went like stink but on way home didn't seem so good...
Also think she might have lots of blow through the oil ways, especially the crank breather. Ended up getting a oil separator from usa so it feeds oil back into sump...but also makes me wonder if issue causing this blow by...
Old 30 April 2012, 11:15 AM
  #4  
swisstonihasher
Scooby Regular
Thread Starter
 
swisstonihasher's Avatar
 
Join Date: Jun 2006
Location: South West
Posts: 1,568
Likes: 0
Received 0 Likes on 0 Posts
Default

Well, done the tests and really happy with the results....cold engine as still no ecu at present so cannot start her.

Cranking for 10 seconds per cylinder:
1 = 10.7
2 = 10.8
3 = 10.8
4 = 10.5

What a pain it is to get the gunson to screw in on the boxer engine...but worth effort. Must be mapping issues as to why thought had problems...I know boost cut was set at the wrong level which I've now adjusted.
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Mattybr5@MB Developments
Full Cars Breaking For Spares
12
18 November 2015 07:03 AM
FuZzBoM
Wheels, Tyres & Brakes
16
04 October 2015 09:49 PM
the shreksta
General Technical
27
02 October 2015 03:20 PM
Ganz1983
Subaru
5
02 October 2015 09:22 AM
shorty87
Other Marques
0
25 September 2015 08:52 PM



Quick Reply: Compression test on cylinders when cold?



All times are GMT +1. The time now is 07:15 AM.