magician

Has anyone tried using an oil catch can in the PCV circuit to relieve the high oil consumption that some of us are seeing on the 5.3??

I know some of the Corvette and Camaro people are using this setup. I've looked at several other forums about this issue and from what I can tell alot of the consumption is caused by the DOD and its selective cylinder shut down and the oil splashing up and bypassing the rings on those cylinders? All of this sounds feasable and I'm looking for a reasonably priced (less than $100) catch can. The ones the Vettes and camaroes use is around $200.

I know some out here have better resources, MDTAHOE, and Shark just to mention a few and I was wondering if anyone out there has anything to add?

73shark

I thought catch cans were when you had excessive blow-by not when oil was getting past the rings into the combustion chamber.

magician

It does seem to be two different symptoms, in my case, I'm seeing an oily film on the inside of the intake on my Tahoe as well as I'm losing oil, which is leading me to the catch can.

I think the oil splashing, as I understand it, is what is related to the DOD.There is a splash panel or tray that gm will put in the oil pan as well as a new style pcv and valve cover but my warranty was over 20k ago. Part of this repair is to soak the pistons and rings in the cylinder in a decarbonizing solution for 2.5 hours. All of this is in a TSB for high oil consumption. Clearly gm believes the problem has more than one possible cause.

I was trying to find more info on both while I try the cheaper route.

magician

Not that anyone really cares here but, after 1400 miles I checked the catch can I installed and it had roughly 30 - 40 cc's of fresh oil. Since I installed the catch can in the pcv circuit I've seen a significant decrease in smoke when the truck is pulling hard. I believe the oil consumption or loss is a reseult of oil being sucked or picked up and delivered to the intake through the pcv orifice tube. This would rule out the DOD and piston ring blow-by as casue. It would also explain why so many have had the splash tray installed in the oil pan and still report oil loss???

Just my 2 cents and what Ive found on my Tahoe...