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Old 11-05-2017, 06:57 PM   #1
zedjr10
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My dry/wet compression test

I got a 92 ex coupe with f22a6. I did a dry/wet compression test today and wanted to see what people think. Results are #1 138/150, #2 140/160, #3 138/149, #4 140/150. Done dry/wet respectively. #2 i put 2 little cap full of oil. The others were one so that might be why of different result. I know too big of difference in wet ussually means worn piston rings. Is 140 ok for this engine. Seems low. Also would my test be a little higher if i had a stronger battery. Car has 247k miles on it.
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Old 11-05-2017, 07:04 PM   #2
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how low was your battery ? slow cranks?
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Old 11-05-2017, 07:38 PM   #3
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how low was your battery ? slow cranks?

It is a cheap 48 dollar walmart battery that is still good unless it is cold outside. It probably has less cranking amps than a good stock battery. I can't imagine it having that much effect but maybe some.
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Old 11-06-2017, 07:42 AM   #4
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It is a cheap 48 dollar walmart battery that is still good unless it is cold outside. It probably has less cranking amps than a good stock battery. I can't imagine it having that much effect but maybe some.
Are you holding the throttle wide open?
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Old 11-06-2017, 11:19 AM   #5
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Are you holding the throttle wide open?
yes throttle is wide open and i let it rotate 8 to 10 compressions.
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Old 11-07-2017, 03:22 PM   #6
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yes throttle is wide open and i let it rotate 8 to 10 compressions.
Ok. Well the numbers are low, but kind of ironic that they are identically low.
From haynes manual

Std 178 psi
Min 135 psi
Max variation between cylinders 28psi


So you are almost minimum. And all I see here is a very old worn out engine.
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Old 11-07-2017, 06:17 PM   #7
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Remember, you're never going to match the factory/manual numbers unless you've got the exact guage and length of hose that they had when they performed their test. This is why you'll often read that unless your numbers have a wild variance between cylinders, e.g. more than 10%, you're fine.

For reference I just did a dry test on mine and came up with a max 185psi for a couple of my cylinders. That's on a motor with 382K that's never been opened up. I'm sure if I'd used the same guage that the person used that came up with that standard number did I'd have a lower number.

Given your results, your head looks to be sealing well and your rings might be a little worn. Nothing to worry about in my opinion.
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Old 11-07-2017, 08:27 PM   #8
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And I could be wrong. It's still weird to see all 4 that low. Is the engine running fine? Orrr...... feels off, low on power all the time?
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Old 11-08-2017, 01:41 AM   #9
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And I could be wrong. It's still weird to see all 4 that low. Is the engine running fine? Orrr...... feels off, low on power all the time?
THe engine performs very well. Except for bad city mpg. Still not sure what is causing that though.
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Old 11-08-2017, 05:43 AM   #10
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THe engine performs very well. Except for bad city mpg. Still not sure what is causing that though.
How many miles on it?
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Old 11-09-2017, 10:38 AM   #11
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There's lots of things that could contribute to lower mileage, the most obvious thing to me being tire pressures and their overall condition. As old as your car is there's surely some maintenance items that could be addressed that could possibly improve it.
I was looking through our cars' maintenance interval items the other day and some of them surprised me at how short the intervals were. I guess I've just been spoiled by newer cars.
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Old 11-19-2017, 12:19 AM   #12
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How many miles on it?
247k miles. The maintenance has been well kept. Was given a complete engine tune up. EGR, plugs, fuel filter, etc.
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Old 11-19-2017, 01:59 AM   #13
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Do you have an automatic or manual transmission?
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Old 11-22-2017, 07:31 PM   #14
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Do you have an automatic or manual transmission?
It's a manual.
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