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Hoping for some advise on burning oil
- on track I burn about 1qt in 20min
- street seems minimal usage
- 2 catch cans fill about 1/5 the usage
- so likely coming from valve seals and/or rings (changed seals with cam)
I think smoking mainly on decel and garage has big sooty black spots from pipes (no cats)
Spark plugs look good to me which I’d think there’d be large variances if coming from rings/seals.
If seals would it be obvious pulling the VCs? Unfortunately don’t remember my usage before changing seals... 1pc seals with LS6 springs.
What year is the car? There was a piston change in March 2001 and then a ring change to the higher tension Napier rings the 3rd week of LS1 production for the 2002 model year. The LS6 got the new rings at the start of 2002 production.
I gotcha on the leak down... I’ve done once before on another car and didn’t tell me much, prob cause lack of experience. Comp test was good-ish... 1cyl about 15% down from avg.
But leak down won’t directly test seals... if test is good then can assume bad seals??
Cars a 2001, not sure of build date. 110k miles with >50 track days.
No, it will not test seals. Just make sure that your piston stays at top dead center. I dont know much about road coarse racing, but 50 track days and 110K miles seems kind of high to me. I think that you are due for a rebuild. Its possible that you have a cracked ring on that one cylinder or that the rings and the ring lands are just wore out and you are getting ring flutter at high RPM's. Some 2001 LS1's had sloopy piston to wall clearances right from the get go. Dont know if yours is one of them though. A quart in 20 minutes?? If it were me, I would yank it out and pull it apart.
What gets me is the consistent plugs, so I assumed head was pooling oil and going through the intake but 2nd catch only picked up fraction. I'll do a harbor freight leak down and may just change the seals... very possible I fracked the install.
For seals any recommendation... I understand int/exh are diff from GM, but I used "BTR hat" seals with LS6 beehive springs. Think I used socket to install and no hammer, just pressed with hand I believe.
What gets me is the consistent plugs, so I assumed head was pooling oil and going through the intake but 2nd catch only picked up fraction. I'll do a harbor freight leak down and may just change the seals... very possible I fracked the install.
For seals any recommendation... I understand int/exh are diff from GM, but I used "BTR hat" seals with LS6 beehive springs. Think I used socket to install and no hammer, just pressed with hand I believe.
In 2002, the LS6-equipped Z06 had an upgraded valley-cover with a new PCV-integrated design to deal with oil consumption, and crank pressure. Might be worth looking into.
My Z51 Coupe however does not have this integrated cover, as I have had the intake manifold off before.
If you have a 1997-2001, the block needs to be notched in the valley for the the new LS6 Z06 cover to fit, however 02s and up do not need to be cut because it is a different block.
(It's argued however, that late 2001's have the LS6 block as well and thus do not need to be cut)
I gotcha on the leak down... I’ve done once before on another car and didn’t tell me much, prob cause lack of experience. Comp test was good-ish... 1cyl about 15% down from avg.
But leak down won’t directly test seals... if test is good then can assume bad seals??
Cars a 2001, not sure of build date. 110k miles with >50 track days.
The 2001's were the worst for burning oil. GM was replacing the rings at the dealer if the car met certain oil usage criteria. Since you are now pushing the car harder than normal street driving, it will exacerbate the problem.
In 2002, the LS6-equipped Z06 had an upgraded valley-cover with a new PCV-integrated design to deal with oil consumption, and crank pressure. Might be worth looking into.
My Z51 Coupe however does not have this integrated cover, as I have had the intake manifold off before.
If you have a 1997-2001, the block needs to be notched in the valley for the the new LS6 Z06 cover to fit, however 02s and up do not need to be cut because it is a different block.
(It's argued however, that late 2001's have the LS6 block as well and thus do not need to be cut)
I did the 04 conversion already and had to notch the block.
Originally Posted by vettenuts
The 2001's were the worst for burning oil. GM was replacing the rings at the dealer if the car met certain oil usage criteria. Since you are now pushing the car harder than normal street driving, it will exacerbate the problem.
Thanks... if I can't reduce the oil consumption, I'll just run it tell it breaks taking a 5qt oil jug per day to the track.
My car had a build date of 08/00 and I did not have to notch the block when switching to the LS6 valley cover. I am still losing a lot of oil though, over a quart in less than 2000 miles of mostly highway driving, and most, if not all of it through the PCV. My catch can was basically full and I can see that the intake line was wet with oil. If I have to pull the engine to fix this, I'll probably just swap in a LS3/L92.
I have a 2001 MN6, and when I got the car, it was going through a quart of oil a month.. 22K miles.
I called an engine shop. checking on engine prices, and he inquired what was wrong with my engine.
He said before you do anything, try driving it like your grandmother. no shift changes above 2500 RPM, for 1500 miles. Then let me know what happens.
So I did.
The rings "reseated" and 94K, now, and still not adding between oil changes.
Last edited by coupeguy2001; 05-09-2019 at 01:57 PM.
Did leak down today... 6 - 9% I don't know typical values, but I'd guess kinda high and potentially rings are the issue. Decided not to do the seals... lot of work as just experiment. Impossible for me to drive under 2500rpms for 1,000 miles, so just gonna live with it
I gotcha on the leak down... I’ve done once before on another car and didn’t tell me much, prob cause lack of experience. Comp test was good-ish... 1cyl about 15% down from avg.
But leak down won’t directly test seals... if test is good then can assume bad seals??
Cars a 2001, not sure of build date. 110k miles with >50 track days.
Ok so its tired. Run the thing til it pukes. no C5 on the planet needs a catch can thats internet bs .
I can't speak to your experience but pulling a valve cover to see if there's a messed up seal is relatively easy in my opinion and worth it if you're drinking that much oil.
I can't speak to your experience but pulling a valve cover to see if there's a messed up seal is relatively easy in my opinion and worth it if you're drinking that much oil.
I did pull the VCs and everything looks good to me... I have these hat 1pc, same for int/exh. Seems difficult to F up the install, so I'm considering them good. But would change if reasonable chance this is it. I'd think plugs wouldn't be so even though. https://www.briantooleyracing.com/ca...kit-hat-style/
I can produce a CLOUD of smoke by below method, but otherwise I see nothing out my mirror
- WOT throttle to about 6k rpms
- Throttle to 0, then give "slight" gas
- This produces a smoke screen cloud out the back
I did this also with intake plugged, so definitely rings, seals or both... any idea which is more likely? I can see both being effected with high vacuum.
I do NOT see smoke under WOT or other conditions. On the track from vid I mostly smoke exiting a corner tipping on the throttle, but more a puff then any sustained smoking.
05-05-2019, 10:24 PM
Oil Consumption Advise
