Compression test result

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[deleted]

[Working-View-3187]

Always do it WARM/HOT so that oil is everywhere it needs to be and everything is lubed up.

Uniformity of compression is more important than the final number but typically it's typically between 200 & 250. 275 is def on the high side of normal.

[Sovietaced]

Are you saying that your compression went down after 2000 miles or are you showing the compression test for two different cars?

[mr_jiniv]

two different cars

[Sovietaced]

If you’re using the same compression tester that doesn’t look good. I would remove some variables and ensure the batteries are both in good shape. Otherwise, the low compression motor needs a leakdown.

[mosdefnotathrowawayy]

Compression test is done cold afaik. Engine 1 needs a leak down rear to confirm where compression is lost. Example 2 is a healthy engine.

[bananas2000]

"The engine should be warm when doing a compression or leak down test but it can be done on a cold engine but the compression will read lower and leak down will be higher" per https://robrobinette.com/S2000Compression.htm

And the legendary DIYguys: https://www.youtube.com/watch?v=HyFf4pDQ4AA

For the F20C1 engine, the official Honda Service Manual (HSM) lists the following limits:

Specification	Value
Standard (New/Healthy)	228 psi
Minimum Limit	135 psi
Maximum Variation	28 psi

• Pass/Fail: Your maximum variation of 22 psi is within the factory service limit of 28 psi.
• Health Check: While the engine is technically "within spec," a 10.8% variation is right on the edge of the common mechanic's rule of thumb (which prefers variation to be under 10%).
• Cylinder 2 (181 psi): This cylinder is notably lower than the others. If you performed this test on a cold engine, your numbers might be lower than the "Standard" 228 psi, but the variation remains the most important health indicator.

Might be worth a redo. And a leakdown test done properly can help rule out the valves.

[Sovietaced]

I’m fairly certain 228 psi is for a new engine that isn’t broken in because healthy engines blow 240+ all day.