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Old 08 January 2016, 06:25 PM
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hedgecutter
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Default Compression test figures ?

Did a compression test yesterday, figures were 3:120 psi, 1:120, 4:125, and 2:130. I am happy that they are fairly even, but rather low.
Mitigating factors were that although the motor was fully warmed up before, it was an hour before I tested it, and it was cool enough to hold my hand against the rocker covers. It was outside as well. I didn`t screw the adaptor in hard as I was worried that it would unscrew in there. It`s a 2005 wagon, 83 000 miles, stage 1.
What do you think..... am I safe?
Got it all back together and it only ran on 3 cylinders, but I was in the dark by that time, so I think a coil pack didn`t push on.
Cheers
Old 09 January 2016, 02:28 PM
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chrispy200+
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I wouldn't be too concerned with those figures, what sort of mileage is the engine on?
Old 09 January 2016, 03:10 PM
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hedgecutter
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Thanks, 83 000 miles
Old 09 January 2016, 03:11 PM
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Coil pack was bad, all running now.
Old 11 January 2016, 07:57 AM
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Anyone else comment on these low figures ?
Old 13 January 2016, 10:37 AM
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ScottyPPP
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Probably just a bit of wear, the numbers on all 4 should be higher, but they're even enough and if it runs well I wouldn't worry.
Old 18 January 2016, 09:23 AM
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wms-racing
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At that milage, the valves and seats will be getting worn, dirty etc, if you do a leakdown test I bet you will hear some air from the inlet and exhaust manifolds. Nothing to worry about but you will be down on power a bit.
Old 18 January 2016, 09:46 AM
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would decoking the engine fix that?
Old 18 January 2016, 10:11 AM
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No Mate, the heads need stripping and the valve seats will proably need recutting and the valves cleaning up and lapping in. It's just what happens as engines get up on miles, just think how many times the valves have opened and shut over all those miles! As ive said its not going to harm the engine in any way, it's just old age creeping in.
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