Do we still need a CCV reroute on the L5P?

[RetroGearhead]

I know on the older Duramax engines, the CCV reroute was mandatory to save the turbo from oil sludge. But looking at the L5P setup, it seems like GM improved the oil separator. Is anyone seeing oily residue in their turbo inlet on these newer trucks, or did they finally fix it?

 

[ForgeSteel]

It’s an improvement, sure, but remember that L5Ps run higher boost and EGTs than older generations. That heat plus even a small amount of oil mist equals baked-on carbon. I’ve seen some high-mileage L5Ps that never had a reroute, and the intake valves looked pretty crusty. I’d rather spend $200 now on a kit than deal with carbon buildup in the heads later on.

 

[HighwayKing]

The L5P setup is a centrifugal style separator, which is a massive upgrade over the old box, but it’s not 100% efficient. If you’re running a heavy tune or towing high EGTs, you’re going to get more blow-by than that stock separator can handle. If you don't want the smell/drips of a full reroute to the atmosphere, at least grab a high-quality Catch Can. I checked my can after a 2,000-mile trip pulling my camper, and it caught about 3 ounces of oily water/sludge. That’s 3 ounces that didn't go through my turbo.