This is for my uncles car. It is an 02 Ram Air. 17,000 miles on the clock. M6 with stock 10 bolt. Patriot stage 2 heads and not sure of the make of cam but its a 231/237 with around .590 lift on both. Last fall the car started smoking really bad at WOT. He left it in the garage all winter. There was a lot of oil in the intake and all the way up in his bellow and TB. I assumed it may be the pcv valve from what I read on here. I picked up a new style pcv valve and took it to him. We took the oil fill cap off while the car was running and it looked like a small factory smoke stack. We hoped that it was a blown head gasket. (hoping for the best really and not wanting to think it was the rings.)
He did a compression test. All cylinders were good (200psi) except the number 4 cylinder (less than 20psi)
So, yesterday with our fingers crossed still hoping head gasket, we took off the head. Not the head gasket. I was told by the local shop that is was most likely the rings had seized in the pistons and that to use a feeler gauge to check around the rings. We didn't have a feeler gauge so we poured water into the cylinder with the piston at the bottom of the stroke to see if it leaked. It didn't. If the rings were bad would the water run into the oil pan?

Oh, and looking at the heads everything looks good as well. Valves are all seated fine and the springs are good too. All the rocker arms were in place and no bent push rods. The cylinder wall looks perfect as well. Everything looks as it should except the spark plug from this cylinder was really fouled. It was completely covered in sludge.

Any ideas on what to do next? Any way to test the rings without pulling the piston?
Thanks for your help.

 

well the water test really would not work, because the top ring could be snapped and the other ring and oil flange could be fine holding the water in. I sounds like a ring would be the logical starting point. anyone else.

 

I can understand that to a point. Would the second ring not hold any more than 20 psi on a compression check though?
Thanks

 

Sounds like you may have broken the piston ring lands. The second ring is a reverse twist oil ring, but I would think if it was healthy the water would have held. Screw the head back down and put pressure in the cylinder, if it comes out the crankcase area pull out the piston.

Kurt