compression test

[kingwick]

tonight i carried out a compression test on my ph2 172 cylinders 2,3,4 all fine at 120 psi cylinder 1 did not register any compression at all. any advice ?
cheers

 

[sideways danny]

120 is LOW!! is the sealing ring on the tester in good condition, and was the face it mates to in the head clean?

 

[kingwick]

the tester is brand new never used before,good point ill check tomorrow make sure its clean and no pits of dirt about it. i thought 120 was normal. what do you think normal psi should be ? any ideas as to what could cause this on one cylinder ?

 

[Cro]

Squirt a little oil into the spark plug hole and do the compression test again mate, if it ups the pressure the rings are going/gone if not then we can look at valves, springs etc

 

[RSTuning]

Put a plug back in number 2 and then re-test 1

 

[mr bognor]

I have the same problem across all cylinders cam timing I have been told is the most likely cause

psi
119 121 121 121 119

 

[RSTuning]

I have seen cheap compression testers read wrong too

 

[Soot1e]

Doesn't matter if it's cheap, it's the consistency thats important. Each cylinder should give similar readings.

 

[RSTuning]

Thats what i mean, the other three maybe perfectly fine

 

[Demi]

whic is the correct compression?
mine was

150 150 156 150.

 

[sideways danny]

thats fairly low, was that hot or cold?

you should be getting a minimum of 170psi when hot, and ideally over 180psi

 

[MicKPM]

Silly question but are you sure you're reading it right? When the big hand points to 12... it means BAR not PSi.

I'm more worried about #1 not reading anything at all... that's valve seal rather than ring seal. What prompted you to carry out a compression test in the first place?

 

[mark123]

Both mine were over 190 all round, even at 130k on the 172.

 

[Michael Woodford MST]

If you replace the engine, please sell me the crank!!

 

[Demi]

Silly question but are you sure you're reading it right? When the big hand points to 12... it means BAR not PSi.

I'm more worried about #1 not reading anything at all... that's valve seal rather than ring seal. What prompted you to carry out a compression test in the first place?

They show me around 12 PSi as you say. It is right?
thx
Demi

 

[Laine_16v]

Mine were 150, 150, 125, 145.

Piston rings were shot, havent had a chance to test new bottom end yet.