ZERO psi on compression test wtf???

1. user_35090 Established Member Joined: Jun 2009 west mids (dudley) Posts: 1201 cammed 106 flatty

   #1 1st April 2018, 13:52

   Just done a compression test and heres my weird results.
   
   Dry test
   
   cylinder 1 = zero
   cylinder 2 = 190 psi
   cylinder 3 = 160 psi
   cylinder 4 = 150 psi
   
   Wet test
   
   cylinder 1 = zero
   cylinder 2 = 220 psi
   cylinder 3 = 210 psi
   cylinder 4 = 200 psi
   
   so clearly i have a HUGE hole some where in the system for cylinder 1 to not create compression.
   
   could this be related to timing? im guessing its got to be something with a stuck valve? even with bad rings, it would still produce some compression...
   
   thoughts??
2. sri_130 Frequent Poster Joined: Apr 2012 Doyncaster Posts: 783

   #2 1st April 2018, 16:28

   Has it just happened or part of a rebuild?
   
   Broken valve spring, I'll go for.
3. user_35090 Established Member Joined: Jun 2009 west mids (dudley) Posts: 1201 cammed 106 flatty

   #3 1st April 2018, 19:10

   part of a rebuild
   
   i never saw this engine run however ive just replaced seals lapped valves etc
   
   defo thinking its something to do with valves because even with a bad head or rings, id still get compression even if very low.
   
   wish i had the means to do a leak down test but i dont
4. Chipwizards Frequent Poster Joined: Nov 2009 Posts: 576

   #4 1st April 2018, 21:38

   Bring it to tdc and blow air down the plug hole, you'll soon see where it's going.
   
   Did you drain the followers?
5. welshpug Saxperience Forum Bum Joined: Jul 2010 South Wales Posts: 3078 ZX 16v, 205 GTI, 309 Goodwood, 405 MI16.

   #5 1st April 2018, 22:28

   8 or 16v?
6. user_35090 Established Member Joined: Jun 2009 west mids (dudley) Posts: 1201 cammed 106 flatty

   #6 2nd April 2018, 01:08

   16v
   
   gunna try rig something with a small air compressor tomorrow to see where my leaks at before i rip the head back off.
   
   i didn't drain followers.
7. MartinObviously Saxperience Forum Bum Joined: Dec 2012 Perth Posts: 3665 Peugeot 106 1.1 Turbo Peugeot 106 1.5D Turbo Peuge

   #7 2nd April 2018, 18:45

   Does the piston move in the bore? lol
8. user_35090 Established Member Joined: Jun 2009 west mids (dudley) Posts: 1201 cammed 106 flatty

   #8 6th April 2018, 20:41

   lol xD
   
   yes it does,
   
   ive managed to do more diagnosis and have came to the conclusion it HAS to be top end causing me the issue. i tried a head with no cams in and it produced 60psi on that cylinder!! yet this other head with the cams in makes;
   
   cylinder 1 - 0psi
   cylinder 2 - 210psi
   cylinder 3 - 200 psi
   cylinder 4 - 200 psi
   
   thinking either severe warpage or a big crack some where..
   
   gunna wack those cams in the "good" head time it up and hopefully i have a result.
9. Chipwizards Frequent Poster Joined: Nov 2009 Posts: 576

   #9 6th April 2018, 23:36

   Put a cylinder leakage tester on it, you'll see where it's going straight away.

   1 user thanked this post: user_35090
10. MartinObviously Saxperience Forum Bum Joined: Dec 2012 Perth Posts: 3665 Peugeot 106 1.1 Turbo Peugeot 106 1.5D Turbo Peuge

    #10 7th April 2018, 10:10

    Quote:

    Originally Posted by stevo1600 lol xD yes it does, ive managed to do more diagnosis and have came to the conclusion it HAS to be top end causing me the issue. i tried a head with no cams in and it produced 60psi on that cylinder!! yet this other head with the cams in makes; cylinder 1 - 0psi cylinder 2 - 210psi cylinder 3 - 200 psi cylinder 4 - 200 psi thinking either severe warpage or a big crack some where.. gunna wack those cams in the "good" head time it up and hopefully i have a result.

    That's bound to be a visible crack if it's going that fast. that would be one hell of a warp, check it with a straight edge?
    
    

    Quote:

    Originally Posted by Chipwizards Put a cylinder leakage tester on it, you'll see where it's going straight away.

    Pretty much this.

    1 user thanked this post: user_35090
11. user_35090 Established Member Joined: Jun 2009 west mids (dudley) Posts: 1201 cammed 106 flatty

    #11 7th April 2018, 14:36

    If only I had access to air!!
    
    My valve lapping skills are atrocious
    
    Just checked the valves and noticed if I looked down into the intake port I can see bloody daylight so was like errrrrr ok
    
    Chucked some water in the port and in went straight past the valve seat and out the other side. 3 valves clearly not seated on that chamber 🙁 hence no compression!
    
    Go ahead and say it guys, I’m a feckin idiot lol ah well live and learn I should have checked it with the water method before hand I guess.
12. welshpug Saxperience Forum Bum Joined: Jul 2010 South Wales Posts: 3078 ZX 16v, 205 GTI, 309 Goodwood, 405 MI16.

    #12 7th April 2018, 17:06

    sounds like you have bent valves from a fitting error, I haven't lapped any valves for years, however I have had them 3 angle cut and they seal beautifully.