S2000 Under The Hood S2000 Technical and Mechanical discussions.

Compression test round two

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Old Sep 18, 2016 | 04:10 PM
  #1  
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Default Compression test round two

I've moved out of Colorado, and was interested in doing a compression test closer to sea level. My results are as follows:

C1: 210, 210
C2: 240, 240
C3: 235, 235
C4: 235, 235

Should I be concerned about cylinder one?
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Old Sep 18, 2016 | 08:09 PM
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Yes. Follow up with a leakdown test.

All the numbers are within the healthy compression range (228 +/- 28) but consistency is key and C1 is strangely not consistent.
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Old Sep 19, 2016 | 04:07 AM
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Do valve adjustment when the motor is cold and then retest the compression. I had a cylinder at 210 and if i remember correctly it had 20% leakage at the rings
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Old Sep 19, 2016 | 06:38 AM
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When was your last valve adjustment? If you are really lucky, its just a valve lash issue, and you've caught it in time.

Otherwise you're hoping its a burnt calve, which can be cleaned up (need to remove head).

If you are not lucky, its rings

Leakdown will tell you. But if its been a while since valve adjustment, I would start with that, then redo compression test. For me that would be easier than leakdown because I don't have the equipment for that.
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Old Sep 19, 2016 | 08:44 AM
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Take the hose from your compressor tester, remove the schrader valve and pump air into the cylinder at TDC, about 70psi will tell you clearly if you're leaking compression from anywhere.
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Old Sep 20, 2016 | 12:35 PM
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Thanks for the replies. Last valve adjustment was done by me but it was also my first ever attempt at it. That was about 5 months ago.

I dont have access to compressed air, so will prolly have the dealer I work at give it a shot.
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Old Sep 21, 2016 | 03:24 PM
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Asked our certified Honda mechanic who has been working on Hondas for years (at Honda dealers only) if he would run a leak down and he was pretty confident in saying "It's fine, don't worry so much."

So I will ask one last time just to be safe -- is it worth worrying about, or is he right? As long as its not actually showing any issues (like down on power or misfires) stop being so worried.

Car has 66k miles.
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Old Sep 21, 2016 | 03:59 PM
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I say keep driving it, tearing the engine down to find your problem right now doesn't make sense. If the car ain't chugging oil and you don't have a CEL, and the car drives fine.
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