^^^It was going to prove weather it was a valve or rings...just a quik look I guess. If you would like, tell him to do the rest and find out what happens. It will be the same results though. If it had a bad valve, the comp would not increase very much. Anyway....good luck with you motor fast

 

I must have misunderstood your statement. I thought you were talking about yours. Your statement kind of reads that way. DOH! Sorry dude!

 

Your missing the point... compression will always always increase when there is oil. The oil helps to seal the rings by "filling" in the microscopic grooves in the walls. There are two factors in interpreting the results obtained.

1st- How much of an increase?
2nd- how does it compare to the others?

Even if it goes up 20lbs on that side, it doesnt mean Sh*t if you havent tested the other cylinders. What if they ALL go up 15-20lbs? Yeah, the rings might be bad, but that doesnt explain why that cylinder is so much lower than all of the others.

Jim

 

When I put oil in the cylinder on the rest it read

cylinder psi

1 135
2 140
3 140
4 150
5 130
6 150
7 100
8 140

What do ya think...Thanks for help thus far..

 

LIKE I SAID

#7's problems ARE NOT its rings as was previously Mis-diagnosed.


1 122
2 122
3 120
4 135
5 115
6 122
7 85
8 130


1 135
2 140
3 140
4 150
5 130
6 150
7 100
8 140

1 13 lb increase
2 18lb
3 20lb
4 15lb
5 15lb
6 28lb?!?!?!?!?!?!
7 15lb
8 10lb

Looking at this Data... #7's rings are fine, however 6 does need rings...badly

Even with the oil, #7 is still much lower than the other cylinders, in fact, its rings are pretty much where the should be relative to the other cylinders.

Now you need to figure out why the cylinder has such low compression. Compressed air will help in doing this, and I recommend the leakdown tester, but you can getby without it (but if your into high performance its a good tool to have). Either way, you are going to want the cylinder just slightly below TDC, and you will hook up the gauge, pumping in roughly 80-100psi. Check for a possible blown head gasket by hooking up your compression gauge to a neighbooring cylinder. If, when your pressurize the cylinder, the gauge begins to read pressure on your neighbooring cylinder, your head gasket is blown. You will also want to take the radiator cap off and check for bubbles, as this would indicate pressure leaking into the waterjackets (blown head gasket). If the coolant level rises alot but does not bubble, this also means the gasket is leaking, there is justa big bubble trapped. If these two tests show the head gasket is ok, move onto your valves.

When your doing your valves, Listen for air leaking from the intake (you will hear it "swooshing"). If you hear absolutly nothing at all when doing this, Its probably the exhaust valve. Ive never experienced an exhaust valve leaking, so I cant really speak from experience on this one, but Id imagine youd be able to hear it just like you can an intake.


Hope this helps

Jim