My 6 speed 05 is burning 1qt/900 miles since I brought it home. Now it has 7750 miles. Dealer's been doing "oil consumption test" since 2000 miles. Now dealer says "it's my driving." I maintain 2500-3000 rpms - dealer says I need to maintain 1800 rpms - drive it in 4th gear in city and 6th gear on freeway. Does this make sense to anybody else?

 

No, it doesn't make any sense except the fact that GM sucks at engineering and technical support. I had the same problem with my C5 and am at the point of litigation with my dealer. Long story that will hopefully end soon and I will post it on this forum when it's done. A small percentage (maybe 5% plus) of the 97-01 C5 6-speeds had an oil consumption problem that stemmed primarily from a fault in the piston ring design and sometimes secondarily in the relatively large piston-to-bore clearance that was part of the original LS1 design (in an effort to minimize friction losses) (resulting in "pistonslap"). The oil is primarily consumed at high revs, light load (like when engine braking down from 5000 rpm) which is when the middle piston ring would enter a "flutter" condition and allow oil to blow by and get consumed. Part of the reason the percentage of problem cars is realtively small is that (A) the ring flutter can only occur on a manual transmission car since the automatics back wouldn't hold a gear if you let off the gas; and the majority of Corvettes built have automatics and (B) in my opinion, only very few (less then 10%?) Corvette owners actually drive their cars hard. First GM came up with a ring kit fix, then shortly thereafter redesigned the whole piston (all LS1s and 6s had the updated piston and rings by model year 02). This supposedly fixed 95% of the problems, but GM's idea of that problem fixed is that you now get 2-3K out of a quart instead of 1K or less. You have an LS2 so I would have thought GM had learned their lesson on the LS1 but maybe not. I would assume the LS2s have the latest/greatest pistons and rings as compared to the LS1s so I don't know why your car would burn that much oil. There is something definately not right. And tell your dealer to go F himself when he tells you to upshift. You paid good money for that car, so as long as it's below redline, it should be able to handle any way you want to drive it. Good luck and if you need more info or to know where I found my resources, let me know but it may require a phone call cause I've got a long and deep story and have been working on my car's problem for 10+ months now.

 

Most people have no problem with oil consumption. I don't burn much and run it like a raped ape. I burned more in the beginning and very little at 8000 miles. I also change the oil at 3000 miles and at that point no noticable drop from the stick level. At 10,000 miles I am sure I would have to add some oil.

 

very few prob. with oil cons. now.
what state are you in?

udriveslow

 

The Dealer will tell you a quart per 1000 is normal. The LS1s had very high oil consumption--I was amazed with my 2000 WS6 T/A--about a qt every 1200-1500 miles. Never saw that before in any of my GM hi-po engines. Zero consumption in my '06 Z-51 (which I mention only because it has an extra 1/2 qt capacity) when I changed at 2000 miles. Haven't checked recently, but I doubt it's burning any. I understood the LS2 solved the problem, per above posts. I don't know that I would lose any sleep--yet, over yours, but I sure as ^%&$ would keep an eye on it and not hesitate to go to GM regional if the dealer doesn't give you the service we PAY FOR buying Corvettes. Good luck!

 

Negative. The dealer should not tell him 1 qt/1000 mi is normal. Unless things have changed, the GM tech bulliten that came out for the C5s stated that oil comsumption of up too 1qt/2000mi was acceptable. So according to what you just wrote, your Trans Am was out of spec by even GMs miserable standards. Did they tell you that rate of oil comsumption was within their technical specs?? Yes, not everyone has oil consumption problems, and some have no problems at all. But most don't drive their cars hard enough and/or in the right way (high rpm/light load; toe-and-heal downshifting anyone?) to know if they would have oil consumption problems under those conditions. My only guess as to why some who do drive hard have no problems while others do is maybe there is a manufacturing problem that is introducing "slop" into the motor assembly. With today's manufacturing proceesses, the tolerances on all the parts should be tight enough to solve these kinds of problems. But, we all know GM engineers went a little overzealous on the original LS1 piston design (large piston-to-bore clearance in an effort to reduce frictional losses = piston slap + oil consumption for some) and completly missed that there was a design flaw with the original ring pack (ring flutter of center ring at high rpm/light load = oil consumption) and from these post by C6 owners, it looks like they indeed did not 100% get their s**t together for the LS2.

 

It's pretty damn bad when you can buy a honda and drive it at redline all day long and never have a problem...then you buy a real sports car and pay real sports car money for the engineering and excellence that should come with a real sports car only to hear you "trusted Chevy dealer" tell you to not take it above 3k rpm when it redlines at 6500...I am really changing my opinion of GM cars...It's so ingrained in my blood I don't know what else I'd drive...but if I do drive something other than GM and end up liking it...I honestly don't believe I'll ever go back to a GM dealer again. I love my Vette, but so far I've had nothing but trouble, and that is not good for the General when this is my first vette and I had really high expectations...

mine burns oil too, but i just switched from a '98SS camaro which burned crazy amounts of oil. so anything comparitively speaking is a small amount.

 

My 2k TA didn't burn any oil and it had the "piston slap" issue....that was until I had the block rebuilt. The dealership is a fruit, it's not your driving, these cars were BUILT to handle revs and not take damage.I'd go over their heads as far up as possible.

 

Actually, the dealer at the time I bought the Trans Am warned me to expect higher consumption, ~ qt/1000-1200, than I was getting with my '97 LT-1 Trans Am. He also informed me of the long break-in period to get the full performance. In that, 5000 miles or so, he was right. I expressed surprise at the oil consumption--never saw or asked for a Tech Pub on it. The Camaro-Z28 and LS1 forums both concurred with that increased consumption as "normal." Some better, of course. I probably used 1/2 quart per 1000 miles on average for the car and never considered it a problem. I did run the car the way it was intended--and this was in Houston's ungodly heat, so had expected somewhat higher consumption.

 

1 qt in 2000 miles is what GM considers acceptable. I still think that is BS. Search for under oil consumption and you may fine the GM documentation. If need be PM me with your e-mail address I'll send it to you.

Check your state lemon laws. File for a BBB arbitration.

PM me for more details.

Vin

 

my 04 LS6 probably uses about a half a quart every 3k miles and i bang that thing off the rev-limiter all the time,every time i drive it (thats what i bought a Z06 for) my 05 C6 Z-51 has only 290 miles so i cant tell you about LS2 consumption.......you know reflecting back the best engine ive had playing with were the old 5.0's wed build 'em,beat 'em the daylights out of them many here over the years hit 200k miles after about having ten of those car throught the years and various vehicles they never burned a drop of oil and for commuters i was changing the oil every 5k alot more often on ones that were beat on and none skipped at beat....literally way farther than any SBC or LT-1 of the day but i do love my LSx motors!

 

Oil consumption? It all depends on your break-in technique and also your cold engine technique.
Run it like a "raped ape" when cold? Plan on it using lots of oil and having reduced engine life.

 

I'm sorry. I know the tone of this is going to sound offensive to you but I promise I really don't mean this towards you personally, just your engineering/technical ideas of what is causing oil consumption in these LS1/LS6/LS2 (anyone know what's been going on with the LS7?) motors. Plus, I've had it with GM's bull**** garbage about 1qt/2000mi being "normal" (maybe in 1960) for any engine, much less one that is supposed to be designed for high performance. Couple that with the fact that I am going through a 10+ month nightmare with my C5 and Chevy dealer, and through that process have witnessed first hand GM's utter lack of technical knowledge and support to the dealer, and I am an admittedly very very pissed off guy. However, as raging as my emotions are now, I feel that as a mechanical engineer, and having consulted with my brother who was an engineer with BMW for over 5 years and my uncle who is an engineer with Chrysler (yeah, I know) for over 20 years, the arguments I make have a sound basis. Now here is the part I know will be hard for you to not take personally: the statement you made above is about 90% BS! Break-in technique? It is my opinion that a modern design engine is 95% broken-in by the first 50 miles on the car, and whether you do it by the manual or the "break 'er in hard" method, no matter which method is best or worst, a modern design engine should still not consume much, if any, oil as a result. The machining tolerances should simply be too tight to allow a wide variation like something from 1965. Cold engine technique? It is my opinion that a modern (admittedly gut instinct here but I would say anything designed and/or built after about 1985-1990) engine is warmed up within a couple minutes after start-up. To be safe, once the coolant needle is off the peg, and on the Corvette you can also use the computer to tell you when the oil temp has started to rise, the car is ready for "raped-ape" action. But again, even if you did the worst case scenario and started hammering the car out of the driveway, a properly designed modern engine should not display oil consumption like this. My motor burned a quart every 800-1000 miles while it was at FULL OPERATING TEMP, not dead COLD! This problem is not the fault of the drivers. It is a design flaw on GM's part, period. And they are too stupid/ignorant/cheap to have at least learned their lesson and fixed it for good between the LS1 and LS2. I'll bet anyone $500 that you can take a new Toyota/Honda/Nissan/BMW (any others you guys would like to include?) off the lot, hammer the **** out of it as soon as they hand you the keys, hammer it again every time you leave the driveway, and you still won't ever burn anything near a quart per 5000 mi. In college I got a 1993 Nissan pick-up (2.5L 4-banger, 5-speed manual) with 80K on the odometer. I drove the ever-living **** out of that thing for over 5 years. I first noticed oil consumption at about 150K miles. By the time her life ended (big tear!, from getting rear-ended and the frame getting bent) at 165K she burned 1/2 quart per 5000 mi. In all that time, the ONLY unscheduled maintenance was to replace a solenoid or electrical switch of some sort that went bad. None of this column lock, roof delaminating, weather seal replacing every 20K mi, etc. BS. Yes, that vehicle was much simpler, but the Japs know how to build cars right and tight, and if something is discovered wrong in the design they will bend over backwards to make it right. I seriously doubt you would have many more problems in a much more complex fully-loaded new Nissan Altima as I had with my truck. And therein lies GM's (and Chrysler's and for some Ford's) problem. I trust a Nissan. I don't trust a Chevy. I loved my Corvette but I bought it because it was a Corvette, not a Chevy or GM product. I accepted the fact that I was taking a certain hit in fit/finish and overall quality by going that route instead of a BMW M3 (yes, I know about the bearing problem on their engines but I also know BMW immediately put 100K warranties on all the engines and will bend over backwards if something goes wrong, and a problem like that is a very uncommon exception rather than the rule with Beemers). But I never would have thought engineering incompetence of this magnitude was still capable in this day and age, even by GM. I will say that I don’t think that moderate oil consumption, in and of itself, will cause any long-term engine reliability concerns. If I found a nice Corvette that burned a quart every 3000-4000 mi, I’d probably keep it. But a quart every 2000 miles or less?? Come on!! That’s obscene and even more than GM can claim is OK with a straight face. Even with a 3-4K mi per quart car I’m a little concerned about the long term effects of the carbon build-up. Quit defending GM. We should demand a properly engineered engine (anyone know of a petition or something of the like?), especially for the price you pay for a Vette. If Kia can do it, GM should be able too also!

 

Ok--but, the fact is that they do burn more oil in general and that is not a single engine anomaly. Also, I may be wrong, but I don't recall hearing many horror stories about higher mileage engine problems on the LS-1 with symptology of higher infant oil consumption. As an engineer you know the statistical significance of standard deviation calculation from mtbf. Have you heard of a really high sigma in engine failures with respect to oil consumption in early usage? That would be an interesting study. What I mean is engine failure being a variable as to high oil consumption in a minority of LS1s. Simply put: the engines with high early oil consumption fail at a much greater rate than those which didn't consume >2000/qt. If the sd was small, it would indicate that there is nothing unusual about oil burners; if large, they would be singled out as ripe for failure. Just my 2c. Sorry about your problems with your car, btw. Good luck in that!

 

Our 2001 C5 with automatic trans burned about 1 qt every 3k miles, annoying but still running great when traded at 68k miles. That 2001 ring design was pretty crummy.

Our 2006 with automatic, same style of driving, burns so little oil that I can barely measure it, about 1 qt every 10k miles; usually I change the oil before adding any.

The C6 is seems sensitive to any tilt (front-rear or left-right) when checking the oil, gas stations that look perfectly level to me will produce oil levels + or - 1/2 qt compared to my flat garage.

 

8300 miles om my 06 and no noticable oil loss.

 

If it were me, I'd take the dealers word for the time being and stick to lower rpms for the next month and see. Maybe just a waste of time, but at least you'd know. Making a 'drivestyle' change may be easier and simpler than tearing into the motor. I would ask/wonder why you cruise at those rpms, when I cruise at 1200 and burn no appreciable oil with my '05 with 9000 miles?

 

Um dont toot your horn to much about the imports my 05 BMW 530i used about the same about if not more oil than my 04 Z06 and i drive the Z a million times harder, i worked in a VW dealership and cannot tell you pieces of crap they are ....big time junk, and as for Toyota, ever hear of "Toyota sludge"? Do a search on it, you'll find alot of "educated", "researching" people are throwing fits becuase their motors are sludging up like crazy. (1.8 turbo VW's are notorious for this, if you dont use synthetic oil every change our fine German friends kindly void your warranty when you have to pull sludge out with a pick) so dont get to high-handed alot of junk out there ...of by the buy a Chrysler and see how long the tranny lasts....Ive worked there too!

 

I'm sorry too, but your post is filled with prejudiced ranting. How can you say GM has a design problem when there are so many people posting zero to very little oil consumption? It simply can't be a design problem or all the engines would have the same problem. Also, for those that think they have zero consumption...think again. It is impossible to have zero oil consumption because a certain (very small) amount of oil is left on the cylinder wall and gets burned during combustion. You don't see a drop in oil level because there is an equal amount of "condensate" that replaces the small amount burned. I agree the OP has relatively high oil consumption (in comparison with others), but I don't think there is anything wrong with 1 qt/2000 miles.

You really need to get one of those foreign cars, I for one will be happy to see you in one. The interesting thing I've noticed as the Japanese cars are getting more popular is I'm hearing more and more people complain about the same things I hear about the American cars. And I see it in all my neighbors Japanese cars...one guy had his new Honda S2000 spend more time at the dealership in the first 4 months than my Corvette has in the 14 years I've had it. When I see a $1000 bill for a 90000 mile maintenance/service check on a Honda Civic, I have to ask myself how stupid are people. In the first 90000 miles of my old Cavaliers life, I didn't spend half that much on the whole car including tires, battery, windshield wipers, and repairs. That car went 225000 miles with nothing done to the engine except a water pump and spark plugs/wires before I took it to the junkyard...because the piece of crap Japanese made (Isuzu) transaxle went out a second time. And don't be so quick to think a Japanese company will step up to the plate for a problem...there are a few executives that use to work at Mitsubishi in jail for "covering up" design flaws in their cars.

Lastly, a lot of the Japanese cars use cast iron rings which require a long elaborate break-in. I don't think you'll hammer on those cars right off the showroom floor and not experience oil consumption and you'll be lucky if you don't glaze the cylinder walls. In contrast, American cars use moly faced/filled rings which seat instantly...the break-in interval is more for the rear end gears and the brakes. Even the cylinder walls are honed to a plateau finish which if you know anything about engines, you'll know that a plateau surface finish is the desired result once rings are broken-in. This is why moly rings seat instantly, the soft moly conforms quickly to the "fine" plateau finish.

Don't wave that $500 around too long, I have a few neighbors more than willing to lighten your wallet!

In the real world (absent of media propaganda), Japanese cars are no better than American cars and American cars are no worse than Japanese cars. I base this on observation, looking at friends/families American versus Japanese cars. I will say I've had to go to way more foreign car dealerships with friends/family to fight for what is right than American dealerships (just one actually, and it was a gray area). And let me tell you the amounts I'm talking about at the foreign dealerships were obscene with a few of them actually criminal...it was funny to see how fast they changed their tune when I arrived on scene as an expert witness gathering evidence for a civil lawsuit and possible criminal prosecution.

PS Good luck with your car!

 

"In the real world (absent of media propaganda), Japanese cars are no better than American cars and American cars are no worse than Japanese cars...."

Having worked for a Tier 1 supplier, the fact is that American built Japanese cars have better quality than those built in Japan--and have almost since the first Honda plant was build in OH. I respect the Japanese as improvers; they have never been innovators. Innovators have much better odds of problems than those who simply wait until the bugs are out and then take it to the next level.