Lost Compression

[Salldritt]

hi

just carried out a compression test and got 16 bar on 1,2&3 but 4 only reached 4bar,,

checked the valves they were seated fine,

any ideas,,

its an e16se engine

[John]

Head gasket failure?

[John]

Have you had the head off to check the valves?

[jimbob-mcgrew]

poor sealing valves
blowing gasket
worn piston rings
warped head
or hairline crack somewhere in the vacinity

probably isn't the valves or the piston rings, as they tend to wear evenly over time.
most likely head gasket, altho best pulling it apart to check everything if unsure

[Andy]

iirc hes just put a replacement head on
Is it running crap?

[meritlover]

explain exactly
how you did the compression test?
how did you 'check the valves were seating'
how did this fault manifest its self?

[Salldritt]

Andy, are you from scarborough autograss by anychance,, reseated all valves the other day with lapping paste etc, and fitted new stem seals,, just checked piston rings all fine,, gonna buy new headgasket on monday and try that,,

[Andy]

i am yes mate,not raced yet as im just invthe process of building my stockhatch nova
are you local like?

[Salldritt]

Yorkshire Dales autograss, i got the red corsa stockhatch, blew it up at nationals, managed to find another block of here, replaced all pistons, and a new valve, and just cant get it runing right, getting low compression out of no.4,, so gonna try another head gasket on monday,,