http://www.youtube.com/watch?v=dinEy...ature=youtu.be

I was not aware that my 30000 mile 2009 LS3 manual transmission C6 did this because its oil consumption is very low. It only consumes 1/2 quart of oil between its 6000 mile oil change interval. The attached video will show you puffs of oil smoke at the end of a dyno pull. That was last years club event. Since then I have added an Elite Engineering catch can. The oil in the intake manifold went from standing liquid to just damp. The catch can does collect some oil. Maybe an inch between oil changes. I retuned the car this year prior to our clubs recent annual Dyno Shootout because I added a ported throttle body and a Halltech MF103 Beehive intake filter system. I noticed that the car still smoked at the end of each pull. Did increase the HP by 15 to 480, but was very disappointed in the smoke again. I emptied the can of a couple of tablespoons of oil the day before the Dyno Shootout. With an empty can, the car produces almost no smoke at the end of the pull. The question I have is, why and where is the oil coming from? The LS3 basically uses no oil between oil changes despite some drag racing, open road racing, and a one mile shootout. The engine produces good power, good gas mileage, and runs great. The puff of smoke freak me out. Some people say it is just an LS engine anomaly--Some do it and some don't. Recommendations??? Thanks

 

The little puffs you see during the run is when the car is pulling timing. If you have a scan you'll find the knock right when that happens. As far as the smoke when you are done, its possibly dumping fuel if your cats got hot, unless that's been turned off in the tune.

I've seen cars do this a few times, I wouldn't worry about it.

 

A "puff" of oil smoke means nothing. Think about 2 stroke motors that are running 50 to 1 gas/oil mixes and how much (little) they smoke.
Rough estimate the 50 to 1 would use a quart for every tank of gas in the ' Vette.

Your 1/2 quart in 6,000 miles is very good for a built 4 stroke motor.

 

No Cats or rear O2's and all of the appropriate ECM stuff has been turned off.

 

On non supercharged or turbocharged engines, I guess the questions are: 1. Is the oil that collects in the intake manifold/catch can coming from the valve guides, the low tension piston rings, or another source? 2. Not all LS series engines exhibit this issue. Why?

 

Just a little oil coming past the valve guides and nothing to be concerned with. If this was happening when you came off the throttle at say 2K rpms you might have a concern.

 

If your engine was really burning oil, it'd be more evident on a cold start. Plus 1/2-qt in 6K miles is too little to even show up in smoke. The smoke you're seeing is probably fuel related, not oil.

 

I was under the impression that oil in the intake comes from the PCV system, which IIRC on the LS3 at least is a simple tube, no valve at all. That's why some people use catch cans.

Our 2009 LS3 uses so little oil I can't really measure it, maybe 1 qt/21k miles if I didn't change it first. And not all of that is coming through the intake, some is doubtless going by the rings & valves which a catch can won't help. So I don't bother with a catch can.

But people who do a lot of hi rev engine braking, like on road courses, might have a greater use for the can.

 

It's from blowby of the piston rings. All piston engines have blowby, thats why the Feds require a PCV system on all cars. Instead of dumping oil fumes directly into the air we cycle the fumes via the PCV thru the combustion chamber where they are burned up.

 

That's correct. And it's called a 'valve', but it's just a passive device with baffles that is supposed to only allow oil fumes, but it's a POS on the Vette. And it probably is the same POS on the LS3 than the LS1. I checked the intake on my new GS since day 1, and it was already all oily in there. Cleaned it, and checked again 300 miles later, and all oily again. Some folks said dry-sump engines were different, but that's not the case. Same crappy PCV system. So bit the bullet and bought the best can available, which is the AMW IMO. I bought EE on both LS1 and LS2. But the AMW is thinner, for installation next to the radiator. Plus it has more internal separation, and best of all, the internal can has several depressions machined inside the can (like circles), to avoid oil being sucked up by the vacuum. Great design. It's the most expensive (almost like the EE), but well worth the little difference. And looks OEM with their bracket with hidden hex bolt.

 

When you let off there is also a short time of high vacuum. I'm sure it pulls a little oil from several places.

 

But it's not called a valve. PCV stands for Positive Crankcase Ventilation. All piston engines have blowby and have to vent the crankcase. Early venting was by an open tube from the engine to under the car, next was breather caps on the engine and now the PCV system.

 

What is weird, is that my 425 RWHP 2002 C5 LS1 (without a catch can)has never smoked on the dyno at the end of the pull like my 2009 C6 LS3 does. One would think that the LS3 would have a better PCV system. As mentioned above, since the C6 uses so little oil, I will not worry about it. Thanks for all of the input.and have a wonderful Merry Christmas

 

My initial impression was it came off the dyno rollers? I didn't go full screen

 

I wish I had that much power. NO--It comes out of the exhaust pipes