my tester has a rubber end i just shove in the hole while a buddy spins over the motor. i tried 3 different cylinders, and they all got the same reading.

 

some one else needs to chime in here, i am prety sure 75 is too low. consistancy is more important but there is also a minimum reading and i think 75 is below the min.

 

ill borrow another compression tester this weekend, and ill compare readings, i might as well check all eight cylinders.

 

also i have no idea how to do a leakdown,, any suggestions for a do it your selfer?

 

75 is way to low.I have over 155 when I did mine.

 

Sounds like the problem I had before I found out I blew the #7. It gave random misfires in #7 and compression was at around 95 while all others were near 150. On ATAP, it would only show misfires on lower RPM, and disappear at higher RPM. The SES light would come and go. I ran it like that for almost 9 months and it then one day, I started hearing a real bad pinging, like there were BB's in the motor. Brought it to my mechanic who took off the heads, and found the piston was blown, an 1.5" section blown through all three ring grooves.

I think the initial SES light was from a crack in the cylinder that was there for the 9 months. After that, the crack finally blew loose, causing the BB noise. I came to this conclusion because there was minimal cylinder wall damage.

Get a leakdown test and see what happens. If it leaks, you're gonna need to lift the heads.

GOOD LUCK!!!!!!!

 

agree 75 is way to low...
try a good screw in type compression tester.
You can also buy a good leak down tester - I have seen several guys make on....
See if I can dig up a photo

 

id appreciate that

 

Cylinder Leakdown Pressure Tester, (Baum: model 1106)


Type in leakdown - This is the typical leakdown tester
2 gauge
You subtract the difference between the gauges and the % difference
is the % of leakage in that clyinder.
Then based on the % - is it rings, valves, headgasket, etc......