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Cylinder compression reading. Are these acceptable?

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Old 14 November 2004, 10:05 AM
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Simon C
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Default Cylinder compression reading. Are these acceptable?

I've had my block compression tested as a check on a running fault. Are these readings acceptable bearing in mind it has doen 175500 miles.

All psi.

Pot 1 : 150
Pot 3 : 145
Pot 2 : 135
Pot 4 : 125

whats the tolerance?

What power losses could I expect to see from these pressure losses.
Old 14 November 2004, 01:23 PM
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scoobtech
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did you do a DRY then WET comp test ??
Old 14 November 2004, 01:34 PM
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right ...acceptable values are 146 - 175 psi

no lower than 138 psi

tolerance across the four is 7psi .

so......you have a problem ....you really need to do a WET test aswell
Old 14 November 2004, 02:01 PM
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Simon C
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The dealership did do both wet and dry, they are the dry values as I have misplaced the wet readings. IIRC they were about 30 psi higher.
Old 14 November 2004, 04:02 PM
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Also what is the symptoms of a shot head gasket as someone has just suggested to me. I'm not loosing coolant or fluid. But whilst I was at PwerStation yesterday I did notice a scrap block and took a look round it. There was no coolant or oil channel between the cylinders, could my loss of compression be caused by a hole in the head gasket between the 2 cylinders??

AS you might have guessed I'm now clutching at straws as I have never cared about a car as much as this 1, and really want to keep it until I can turn it into a project.
Old 14 November 2004, 07:05 PM
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scoobtech
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ok......i`m truely sorry 2 be the bearer of bad news but.......if your wet compression readings where 30 psi higher ....THATS BAD !!

this indicates that you have either worn piston rings & or worn bores or both .........either means your engine neads to come out & the heads off for a visual inspection .

your headgaskit/s could be gone aswell but they will need replacing anyway .

whats your location ?

scott
Old 14 November 2004, 07:09 PM
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Simon C
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I'm in Hatfield in Herts.
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