HarryD

So what was wrong with ALL your cylinders that they were ALL the same consistently low PSI at the same time?

Shop manual says there's a max variation of 28 PSI -- that's where we get the "consistency across all cylinders" parameter.

If that's the dumbest thing you've seen on s2ki, you need to spend more time here.

miloking

Yea you are right so dumb its much better to have one cylinder with way lower reading... who needs same compression across whole engine.

Car Analogy

Consistency isn't an S2k thing, its an industry wide accepted concept.

Engines rarely wear completely evenly. When engine wear gets bad enough that it starts to effect power significantly or makes it run bad, there will be unevenness of its compression.

If all the cylinders are the same, engine probably doesn't have much wear. If there is significant variance, there is wear or damage. Period.

Can an engine wear evenly, such that the cylinders are all still close, but worn so badly that engine runs bad and is way down on power? Yes. Its not as common, but possible. This is why there is also a minimum compression spec.

tama05

^Correct, and there may be nothing wrong with the engine at all, which is why I suggested using a better quality gauge, because I have seen the difference first hand. I understand consistency isn't everything, but if the cylinders are within certain psi of each other, the gauge itself may be at fault for low readings. There's a ton of people on here who have witnessed the same which led me to getting a new compression tester myself. Just giving OP some ideas of what can be done if they question the results.

Charper732

You see, that is where you are wrong. I don't know what your experience is, but in general 180 psi is a lot when compared to a lot of engines out there. The F20s Ive seen with low comp across the board still ran fine, albiet maybe down on power if you are use to driving a s2k. You would never know they had low comp. But yet they leaked 40-45% at the rings. "if all the cylinders are the same, the engine doesn't have much wear" well I just proved to you that is wrong soooo.....

Car Analogy

Yes, I should have said 'probably' doesn't have much wear. Like I said after, its possible, but less likely, to have even wear down to min spec. So I obviously didn't mean even compression is a guarantee of engine being ok.

Bit again, this isn't an S forum thing, its an industry thing. So your argument is with the automotive industry in its entirety...