6.0L suddenly burning oil @ start-up

12dbsinad · May 5, 2023

2005 2500HD 6.0L 205K miles here. All of a sudden out of the clear blue truck starts burning oil on startup, fairly good cloud of smoke, but sometimes it does not do it at all. Has not done it for the past few days but tonight leaving work she smoked a real good cloud, then cleared up. Seems to run fine otherwise. Started about a week ago and as I said, sudden. Never any visible smoke before. PCV issue? I find it hard to believe it's valve guides? Suggestions?

davester · May 5, 2023

Yeah, I would start with the pcv system. My '04 3500/6.0 didn't have a old-school rattling replaceable pcv valve, but a pressed in fixed orific one (which I found out after wrecking it getting it out).

You might:

-add a catch can

-pull off the valve cover, make sure the port is clean and that the internal baffle is clean and the holes in it aren't plugged

newdude · May 5, 2023

X2 on what Davester said. Check the integrated orifice in the valve cover and check the baffling on the underside of the covers.

If anything after checking those out doesn't fix the oil on startup, next likely target is valve seals.

12dbsinad · May 6, 2023

Thanks guys, will take off valve cover and see if I see anything obvious. Today on way to work slight puff of smoke on start-up, barely noticeable. When I left I did not see anything on start-up. Yesterday it smoked like crazy, very strange. Will report back on my findings for anyone reading this in the future. Thanks.

MORSNO · May 15, 2023

On 5/5/2023 at 8:50 PM, 12dbsinad said:

Thanks guys, will take off valve cover and see if I see anything obvious. Today on way to work slight puff of smoke on start-up, barely noticeable. When I left I did not see anything on start-up. Yesterday it smoked like crazy, very strange. Will report back on my findings for anyone reading this in the future. Thanks.

My 1988 with the 350ci engine started blowing blue on startup due to worn valve guides.