Here are the compression test results for my 1994 xjs 2 + 2 w/ 111k miles:

1) 162.5
2) 172.5
3) 172.5
4) 172.5
5) 167.5
6) 167.5

According to the manual I have the compression should be 160-170 for the 4.0 engine and there should be no more than a difference of 10psi. I'm right on the nose with the first cylinder being at 162.5. I did several tests and they all come out the same. Should I be concerned? Is this car worthy of a new paint job?

 

damn. just realized that I forgot to leave the throttle open. the above test is with the throttle closed. does this make a big difference?

 

It should make no difference as both inlet and exhaust valves will be closed for test. I would not be too concerned as it is still in tolerance.

Did you re-test more than once? and if so I would use the mean of your readings

 

Actually, not having the throttle open can make a difference. In any case, I personally would not be concerned about the variance you have, especially for the miles. Paint 'er up and enjoy!

Cheers,