Compression test? - experts please

1. Mark51p Super Moderator Joined: Sep 2006 Wakefield Posts: 14427 Golf GT

   #1 5th February 2008, 21:31

   does anyone know what psi/bar a compression test should be for a 1.4 8v saxo? i know that the vts ones are about 220psi but not sure if thats for mine.
   
   also what is a safe difference to have between each cylinder?
   
   if your compressions are low what does this mean?
   
   if your compressions are high what does this mean?
2. jimmy2006 Regular Poster Joined: Feb 2008 Posts: 419

   #2 5th February 2008, 21:48

   Test your engine first then post the compression of all 4
3. Joesnow Frequent Poster Joined: May 2006 Posts: 691 Mk 1 VTS poseidon blue

   #3 5th February 2008, 21:56

   Any difference of 2bar between cylinders indicates a fault from what I remember - think I got that from a haynes manual...
4. Mark51p Super Moderator Joined: Sep 2006 Wakefield Posts: 14427 Golf GT

   #4 5th February 2008, 21:59

   what would be the causes of this?
5. Joesnow Frequent Poster Joined: May 2006 Posts: 691 Mk 1 VTS poseidon blue

   #5 5th February 2008, 22:09

   Bent/burnt valves on a particular cylinder would show up as a low reading on 1 cylinder.
   
   Low compression on 2 cylinders would indicate headgasket failure between 2 cylinders
   
   Worn piston rings could be the cause, I think it would happen on them all though... you can eliminate piston ring wear by pouring a teaspoon of oil into the cylinder before the test...
   
   Post up the test results along with your symptoms and I'm sure someone will be able to help!
6. Mark51p Super Moderator Joined: Sep 2006 Wakefield Posts: 14427 Golf GT

   #6 6th February 2008, 15:51

   ^^ what does the oil do?
   
   will be posting them up sometime this week hopefully if i can get hold of a tester
7. Quick Saxperience Post Whore Joined: Mar 2003 United Kingdom (England) Posts: 7064

   #7 6th February 2008, 16:00

   The oil seals the cylinder like the rings do!
8. hesslevtr Saxperience Hardcore! Joined: May 2004 Hull (England) Posts: 18709 1.6 vtr

   #8 6th February 2008, 18:19

   my vtr were all 200psi
9. jimmy2006 Regular Poster Joined: Feb 2008 Posts: 419

   #9 6th February 2008, 21:34

   good compression
10. williamsvts Saxperience Post Whore Joined: Feb 2006 northumberland Posts: 7693 pulsar gtir, mk4 astra sxi

    #10 8th February 2008, 13:34

    i would do a leak down test. you can still get good compression with dead rings. leakdown test is more reliable.
11. Mark51p Super Moderator Joined: Sep 2006 Wakefield Posts: 14427 Golf GT

    #11 8th February 2008, 19:32

    whats a leak down test?