2006 S80 with about 135k miles 2.5t. Looking at it for someone before they send their kid on a long trip with it. I am not a mechanic, know a lot, but never enough. Rented a compression tester and checked compression across all 5 cylinders. Dry (but not wide open throttle) 145-155psi. After putting back together now have a single cylinder misfire.

2 questions,
1- Is that compression acceptable, anything to be concerned about?
2- Why the misfire? I removed and reinstalled plug and coil pack and it is still misfiring. Could the coil have been damaged? I cannot swap them right now, but that is my next step unless someone has a better idea.

I pulled the fuel pump fuse during compression test. There were no codes or misfire prior to what I did.

Thoughts on compression numbers and possible mistakes made that is causing misfire greatly appreciated.

 

Turns out the #3 coil took a dump. Replaced with Bosch coil, runs like a champ