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i have a 2002 LS1 in my boat. Engine has 700 hours (probably something like 60,000 miles in car lingo) Boat is running a constant 3000 rpm pulling skiers and am burning a quart in approx 40 hours. Does this sound normal or should I be addressing something? boat has had about 20 oil changes at like 30-40 hours each year. In the last 3 years it's been running harder b/c we do about "500" 0-30 pulls getting skier up each year for the slalom course.
Normal. All LS engines with PCV setups burn oil. The PCV setup sucks oil vapors (blowby and valvetrain windage vapors) into the intake, where it’s ingested. Its emissions 101. My newest work van in my electrical business fleet is a 2020 2500 with the 6.0. It has burned almost a quart of oil between oil changes, since it was brand new. Same way with all my vans.
You're fine as is, as Che70velle says. Bottom line is the LS crankcase ventilation sucks, period. The newer LT style engines with DI have a far better PCV setup. They had to do something, because with direct injection, the intake valve never sees any detergents in the gasoline, if any. Even raw gas helps keep the intake valves clean-er. DI makes that impossible. A number of us high performance guys don't run the PCV OR a catch can. We vent to atmosphere, like every engine for the first 60 odd years of the 20th century did.
does the PVC valve need replaced or should I just leave it alone? - doesn't seem excessive
You could try replacing it, but I don’t think it will help. It’s just the nature of the beast.
Most on here know how **** I am about my building practices, but it goes into everything. When we change oil on our stuff, we dump the waste oil into a measurable bottle, just to purposefully see how much it’s used. That’s how I know exactly how much these engines use.
Hello,
My 2002 5.3, had the cold piston knock and it burned oil. The factory gave it extra piston to bore clearance! A bore job with new pistons and a Corvette style valley cover with the inlet for the PCV system ...no more oil consumption.
Easy way to check is to pull the spark plugs and see how the carbon build up is on the pistons with a bore scope. A wet but clean area next to the bore shows oil consumption. The oil cleans the carbon off the edge of the pistons, while leaving the build up in the center. Which would point to a ring job.
I can not tell which type your engine has or what year GM used the "new" valley cover but that type does not use a PCV.
Hope this helps
I wish my engine looked so good!
Last edited by Metalchipper; Nov 3, 2025 at 10:03 PM.
Hello,
In more inline with the other comments............
Burning 1 quart in 40 hours in a boat would compare with a truck pulling a heavy trailer up hill for about 3000 miles in second gear, so that is not so bad for "oil burn."
thanks for the the help guys - so it sounds like I can rule out dirty rings at this low hour mark and it's just an LS1 thing. I put in 6 quarts at the start of the season. I did put in some expensive HPL oil for this upcoming season and hopefully it will clean things up a tad - or it was just wasted money haha