Compression

[xoldog400]

hello, my mate's 172 is sounding like it's running on 3 cylinders. the cables, spark plugs and coilpack are new...but the compression test is showing that the compression on cylinder nr.4 is 0! the other 3 are ok.
any ideas?

 

[mr.pink87]

Timing out? Damaged valve, piston(-rings) could be possible faults. A leakdown test may help or scope the cylinder.

 

[Sam@NP]

^what he said.

 

[Laine_16v]

Whatever it is, it will be expensive to fix.

 

[MicKPM]

Head off, replace 2/4 bent valves, refit... Nice weekend DIY job that.