low cylinder compression
 

Hi

I have a 2008 Accord EXL- L4

The cylinder compression test gives 138psi, 138psi, 139psi and 138psi for each of the cylinders. It looks like these numbers are quite low for an engine that has a compression ratio of 10.5:1.

can anyone tell me is this normal for this car?

I don't have a good manual with me right now but that doesn't sound that far off....the 98-02 manual I have says 135 psi as the min. The good thing is the range between all of the cyl, almost no difference.
There are things "while" doing the test that can also impact the results.

I wanna say it's around 180-200psi from what I remember reading on Alldata. That was for a k20 so I'm sure the number should be similar

I checked my 2003-2007 Honda shop manual and spec pressure is a minimum 135 psi. No average or expected pressures are provided. I have obtained 180-200 psi on earlier (1990 and 1994) Accord 4-cylinders.

Was throttle plate fully open and engine cranked at least 4 compression cycles?

Do you know the compression gauge is reasonable accurate?

I would rule out possible errors first.

good luck

Corrected for altitude?

Did you push the gas pedal to the floor when (wide open throttle?) doing the compression test?

:) and some suggest to disable the fuel as well.

Thanks for the replies guys.

Threes reading are from the Honda Dealer that just sold me the 2008 Accord. The altitude here is about sea level. I'm in Ontario, Canada.
The reason that i want to ask is because the exhaust is very dirty in comparison to my 2000 accord and also its using quite a bit of fuel in comparison to a 2006 accord i had before. I think that they sold me a bad car. I bought an extended warranty, and they did a test on it. the recorded cylinder compression test is between 138 and 139 psi. which is fine for a 2006 accord that has a compression ratio of 9.7:1 or a 2000 accord with compression ratio of 9.4:1, however the 2008 accord has a compression ratio of 10.5:1. With such a high compression ration i would think this engine will have a higher min pressure. The car currently has 140k km on it or about 90k miles on it

So do you think that this engine is bad, damaged, or has problems? If so how can i get it fixed?

That compression is too low in my opinion. I think that the person doing the test did not push the gas pedal down to allow maximum air flow into the engine. There was a recent thread on here where another dealership did the same thing.

I also did not push down on the gas pedal the first time I did a compression test and got similar readings as your engine.

I think you need to nail down some facts before you assume that the engine is bad:

• Does emissions testing bear out that the exhaust on your 2008 is "very dirty" compared to your 2000? If so, then that problem needs to be chased down. It may be something as simple as worn spark plugs or a bad oxygen sensor.
• Is your 2008 substantially similar to your 2006? Automatic vs. manual, four cylinder vs. six cylinder, trim level, etc. If so, what KPG were you averaging with the 2006 and what KPG are you getting with the 2008?
• There's an inherent conflict of interest with the selling dealer performing the compression test. $50 will buy you a compression test from an independent shop. Get this done before you decide if low compression is a problem.