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are these compression readings goo?

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Old 14 February 2007, 03:03 PM
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VAL113R
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Default are these compression readings goo?

I was getting new plugs fitted to my 93 wrx. I decided to get a compression test done at the same time.

The readings on all cylinders was 125

The car has done 93k miles. Is this good or bad?
Old 14 February 2007, 04:02 PM
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34srm
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would have thought it would be more like 170+
Old 14 February 2007, 04:48 PM
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Yes the readings are a little on the low side, was the motor upto temp ?

info for pre 97

981 - 1177kPa
10.0 - 12.0kg/cm2
142 - 171psi

Limit
834kPa
8.5kg/cm2
121psi

Max difference between cylinders
196kPA
2.0kg/cm2
28psi
Old 14 February 2007, 10:33 PM
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VAL113R
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I don't think it was up to temperature. The car was in the garage for 2 days. I was getting some electrical work done on it. It was definitely cold when they did the test.

The thing is the car has never missed a beat. Doing a search on here it seems a lot of people are getting the same sort of results, even though there are posts afterwards from people saying they're too low.

I would be intrigued to hear from these people to find out if their engine went bang shortly afterwards or anything?


Originally Posted by *Un-ink*
Yes the readings are a little on the low side, was the motor upto temp ?

info for pre 97

981 - 1177kPa
10.0 - 12.0kg/cm2
142 - 171psi

Limit
834kPa
8.5kg/cm2
121psi

Max difference between cylinders
196kPA
2.0kg/cm2
28psi
Old 14 February 2007, 11:21 PM
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Jolly Green Monster
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as long as all four are similar compression I wouldn't worry.. especially if the engine was cold.

Simon
Old 15 February 2007, 12:32 AM
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silent running
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Mine came out at 155-170 across all four cylinders, 2000 miles after a rebuild. Standard 2.0 turbo.
Old 15 February 2007, 08:39 AM
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Slowboy Racing
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You would need to do this test when the motor is up to temp to get an accurate reading. Based on that I am sure it will be fine as the rings expand the seal will be greater giving you less leakage and as you have said they all read 125, it would be a concern if there where quite different readings between each cylinder.
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