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Engine Compression Specifications?

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YOUR RESEARCHEngine Compression Specifications?

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Test probably started

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Suggestion
Test probably started on bank 1 and ended on the other bank.
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Engine Compression Specifications?

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Suggestion · Original poster
When I got home, I noticed on the invoice there were some figures for the test results:
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Engine Compression Specifications?

Test results were very good

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Suggestion · Original poster
and the compression test results were very good.
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Engine Compression Specifications?

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Suggestion
Test probably started on bank 1 and ended on the other bank.
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Engine Compression Specifications?

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Suggestion · Original poster
When I got home, I noticed on the invoice there were some figures for the test results:
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Engine Compression Specifications?

Test results were very good

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Suggestion · Original poster
and the compression test results were very good.
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Engine Compression Specifications?

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POST 1 / ORIGINAL POSTEROriginal post

Does anybody here know what the compression specs are for a 2002 C4s engine? I recently had a full maintenance service done on the car, including a compression test. and my mechanic told me the car looks solid, and the compression test results were very good. When I got home, I noticed on the invoice there were some figures for the test results: #1- 270 #2- 265 #3- 265 #4- 255 #5- 255 #6- 255 My guess is they refer to the cylinders and the respective numbers in psi. I'm curious for comparison, what the numbers would be for a "perfect" engine.

POST 2Original post

I have no idea what the M96 psi absolute #'s should be, but you'd like to see very little variance between cylinders. On a 951 motor (low static compression turbo motor) 150-ish psi with no more than 5 psi difference (3%) among cylinders would be a typical strong motor in good shape. At least that's what I recall. 5% seems a little higher than you'd like, but maybe that's typical for these motors.

POST 3 / ORIGINAL POSTEROriginal post

Any help... please??

POST 4Original post

Variance between cylinders is perfectly fine. New cars often have as much as a 10% difference between cylinders which is at the high limit of variance. The differences between the cylinders quickly lessen after some hard driving. So, regardless of the absolute PSI, the important data is the difference between cylinders, which you have very little of. So, it is safe to assume that your valves, cam and cylinders are in great shape. This assumes that the test was performed properly with ALL plugs removed and throttlebody wide open and engine fully warmed up. Remember, as the engine cools, they tends to be less pressure. Test probably started on bank 1 and ended on the other bank.

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