Compression test results.

Hi peeps!
92 sport 2 door 4.0 stick

my XJ has 204,xxx on it so i was considering a head rebuild vs a new motor and checked the compression to give me an idea of what direction to go in.
im posting the results to see what you all think. evidently if you rebuild the head with bad or weak rings you will cause further damage. i have searched all around and it seems that stock compression should be between 120-150 psi. that seems like a wide range to me.

# dry wet
1-146 170
2-150 160
3-148 161
4-151 180
5-150 158
6-146 158

so far all i can think of is
1. carbon build up
2. the motor has been replaced by the P.O. and its fine leave it alone
3. the rings arent seating correctly/oil didnt spread wet test again

so im gonna wet test again and compare the numbers

what do you all think?
cheers!

wet retest results are
1-165
2-161
3-170
4-187
5-169
6-170

They are with in 30 lbs of each other and nice and high. I wouldn't do a thing.

Yeah being that high it would say that the engine is nice and tight still. What problems or symptoms are you having that made you decide to check things out in the first place.

Bails, nothing really just thinking that as many miles as it has would need the head freshened up.

If it isn't broke don't fix it.

ha!

Looks like great numbers to me too. Drive it another 200,000 miles.

If there are no symptoms I would not touch the head or anything else. My last two XJ's have gone well over 250K without a hint of internal engine trouble, and never burned a drop of oil either. Wait until something breaks if it ever does.

If you're worried about carbon buildup, you can always run something like GM top engine cleaner through it, and all your carbon will end up in a cloud over the neighborhood (great fun!). But I wouldn't even bother with that unless your engine has started knocking.