Bad Rings?

[boostmaster]

By mistake today I found that under boost without my dipstick in that I would get a spray of oil up my dipstick tube into the engine compartment. I know it could be pcv but it is brand new delco unit. Any way I had been having problems with this car running rough and missing after warm up. I checked everything electronic and found no problems, so I checked the compression and these are the results cyl-1@145, 3@125, 5@150 cyl2@150, 4@110, 6@147. now with cylinders 3 and 4 both excatly opposite of each other having low compression do you think I could have carbon build from the EGR or could it be a combination of both. When I squirt a little oil in the cylinders compression goes up to around 140psi, I know that means possibly rings but if there were excessive carbon build up on the valves would'nt the oil seal it up any possible leak as well. This engine only has 93k on it and I can't believe it needs a rebuild.

 

[gnsrule]

Im betting on rings, but the next step would be a cylinder leakdown on those cylinders. Take the shrader valve out of the end of your compression guage whip, swcrew it in the head and plug the other end to a compresser. Cut the air down w/ a pair of vice grips. BTW, u gotta bar the engine over to TDC on the cylinder your checking and cut the air down enuff so it dont roll the crank over. With the air pluged in, listen thru the breather hole, intake and exhaust. A hissing sound indicates the source of leakage. Hissing thru the breather would be rings.
Hope this helps.

 

[boostmaster]

anyone else have any thoughts one this.

 

[gnsrule]

Any update yet ??

 

[boostmaster]

bad rings

pulled engine this week end broke down top end and wellah!!!! blown head gasket on cylinder #3 into the lifter valley, thats why the oil pan was pressurerising. the inside of the motor was otherwise clean you could still see the factory hone marks, so I'm at a dilema rebuild or do a valve job upgrade springs, replace rod and main bearings and call it the day.