I took my 3 slow motor to the mechanic to have a check up. The compression check showed a difference of 10 to 15 PSI difference between cylinders.

1>180
2>170
3>180
4>175
5>185
6>170

Is this something that is normal with the 3 slow motor?
I would to here your thoughts. If you have some facts I would like to here about them too.

Thanks,

Amusement

 

±10% from highest to lowest. You're within that, if one were <166.5psi you may have issues.

Or you can measure it as average±5%. ie, in your case, average is 176.6667. The acceptable range would be 167.83-185.50. No seriously deviated cylinders.

Either way of measuring, you're OK.

 

Amusement,
Is there a reason you decided to have a compression check? I was just wondering if you had any odd symptoms or anything.

I'm not going to do a compression check because I'm afraid of what it might say. I'll just drive her till she dies.

 

The compression test was part of a tune-up. The mechanic said the compression was normal but, I wanted a second, third ... opinions.

There is nothing wrong .. as I can feel, see or hear. Don't like the idea of being stranded on the road. I try to be proactive.

 

No, those pressures are fine.
Anything above 150 psi (albeit low) should be ok to drive.

Funny how all your lower pressures were on one side of the engine not just at random like you would expect. Just an observation, that's all.