6.2 SS OIL CONSUMPTION-PLEASE READ

[SC2150]

Originally Posted by sullivang

SC2150,

GM says the rings are sticking, would that be considered the same as not seating correctly?

Sticking rings is not common at all on a newer motor. Now one that has run with excess oil ingestion for an extended time sure can as the carbon & "gunk" build-up can cause this. I would still look toward the valley baffel/orfice first.

Originally Posted by SSE 4 2SS

I am not answering for an obvious professional, but to add to some of the previous information... This is from an article that helped me understand the process and reasoning behind a hard break in.

"When your piston rings are broken in or seated, they do not allow the gases of combustion to escape into the crankcase. This lack of "blow-by" keeps your engine running cleaner and cooler by preventing hot combustion gases and by-products from entering the crankcase. Excessive "blow-by" will cause the crankcase section of the engine to become pressurized and contaminated with combustion gases, which in turn will force normal oil vapors out of the engine's breather, causing the engine to consume excessive amounts of oil. In addition to sealing combustion gases in the combustion chamber, piston rings must also manage the amount of oil present on the cylinder walls for lubrication. If the rings do not seat properly, they cannot perform this function and will allow excessive amounts of oil to accumulate on the cylinder wall surfaces. This oil is burned each and every time the cylinder fires. The burning of this oil, coupled with "blow-by" induced engine breathing, are reasons that an engine that hasn't been broken in will consume more than its share of oil."

This could also explain lots of oil being caught in the catch cans as has been mentioned...

"When the engine is operating, a force known as Break Mean Effective Pressure or B.M.E.P is generated within the combustion chamber. B.M.E.P. is the resultant force produced from the controlled burning of the fuel air mixture that the engine runs on. The higher the power setting the engine is running at, the higher the B.M.E.P. is and conversely as the power setting is lowered the B.M.E.P. becomes less.

B.M.E.P is an important part of the break in process. When the engine is running, B.M.E.P. is present in the cylinder behind the piston rings and it's force pushes the piston ring outward against the coarse honed cylinder wall. The higher the B.M.E.P, the harder the piston ring is pushed against the wall. The surface temperature at the piston ring face and cylinder wall interface will be greater with high B.M.E.P. than with low B.M.E.P. This is because we are pushing the ring harder against the rough cylinder wall surface causing high amounts of friction and thus heat. The primary deterrent of break in is this heat. Allowing to much heat to build up at the ring to cylinder wall interface will cause the lubricating oil that is present to break down and glaze the cylinder wall surface. This glaze will prevent any further seating of the piston rings. If glazing is allowed to happen break in will never occur. We must achieve a happy medium where we are pushing on the ring hard enough to wear it in but not hard enough to generate enough heat to cause glazing. If glazing should occur, the only remedy is to remove the effected cylinder, re-hone it and replace the piston rings and start the whole process over again"

If you look at the cross section profile of a piston ring, it is beveled on the inner and outer top surface. This larger area allows for the pressure of combustion to get behind the ring, down inside the piston ring groove, and assist in pushing the ring outward towards the cylinder wall...

This is an excerpt from an article I've read... and it went a long way in helping me understand the hard break in method so many people are against... As for my car, with the factory motor and with my new build, both of them were broken in hard but within certain parameters...

I have a question... If your car has a manual transmission, do you do a lot of engine braking...

I'm not saying this is the problem, just asking a question...

This is exceptionally bad on a new motor during the break in period... Back pressure on the rings during deceleration causes the rings to float in the ring valleys, which can allow for deposits that can cause the rings to stick.... also preventing them from ever "seating" properly... just another thought...

Excelent contribution and a good explanation. VERY accurate.

[ALLTRBO]

Good info in this thread, thanks all.

I was already planning on doing a hard break-in on my new SS (couple more weeks!), but now I'm seriously considering changing the oil to conventional for my break-in period, then back to synthetic (forever thereafter).

I also plan on dyno'ing it straight away, then also after a thousand miles or so to see what (if any) power difference there is.

[RiCorvette]

Originally Posted by sullivang

Ricamaro. Are you in Lakewood California?

Aye!
Are you near by, or are you Sullivang from Solvang?

[SC2150]

Keep us updated. Documenting it all is important to gathering more info and yes, break in on conventional and then go to full syn. Also, put a good functioning catch can on right away. The pics of the oil in the intake are with only a few miles on brand new cars that came in.

[RiCorvette]

If Blow-by is a consideration then could it be detected with a cylinder pressure gauge? What is the min-max cylinder pressure for the LS3 or L99?

[VR Baron]

My 2012 M6 has 3400 miles, and little oil consumption, normal use I guess. catch can on for 2900 miles and only a little came out,about 1/4" deep in bottom of normal drinking glass.When I changed the oil I meassured what came out and had 7.5 qts, so some use, some still in the motor that doesnt drain out.

[90503]

Originally Posted by VR Baron

My 2012 M6 has 3400 miles, and little oil consumption, normal use I guess. catch can on for 2900 miles and only a little came out,about 1/4" deep in bottom of normal drinking glass.When I changed the oil I measuured what came out and had 7.5 qts, so some use, some still in the motor that doeant drain out.

I too believe this is an area of concern. What I find interesting is how GM instructs what appears to be an incorrect way to break in the engine, as recommending the wrong type of oil! This is amazing and horrible if found to be true.
If so, I don't see how the outcome could be anything but a future class-action lawsuit, and/or a massive recall.

My experience so far, no catch can, only one oil change, no noticeable oil use...First car that's ever had full synthetic...I always believed full synthetic was somewhat of a gimmick to increase rated mpg, and that "regular" oil was perfectly acceptable as a substitute. I was also under the impression that engines these days were already "pretested/broken in" to some degree on the bench before assembly. Perhaps not.
Keeping my finger crossed and hoping for the best!! Thanks

[SC2150]

Originally Posted by Ricamaro

If Blow-by is a consideration then could it be detected with a cylinder pressure gauge? What is the min-max cylinder pressure for the LS3 or L99?

Leak down test is the only way and every guage brand will read slightly different. As a rull any more than 20% is considered an issue.

Originally Posted by VR Baron

My 2012 M6 has 3400 miles, and little oil consumption, normal use I guess. catch can on for 2900 miles and only a little came out,about 1/4" deep in bottom of normal drinking glass.When I changed the oil I measuured what came out and had 7.5 qts, so some use, some still in the motor that doeant drain out.

You have a good, properly ring seated motor w/out the valley baffel issues. Good job!

Originally Posted by 90503

I too believe this is an area of concern. What I find interesting is how GM instructs what appears to be an incorrect way to break in the engine, as recommending the wrong type of oil! This is amazing and horrible if found to be true.
If so, I don't see how the outcome could be anything but a future class-action lawsuit, and/or a massive recall.

My experience so far, no catch can, only one oil change, no noticeable oil use...First car that's ever had full synthetic...I always believed full synthetic was somewhat of a gimmick to increase rated mpg, and that "regular" oil was perfectly acceptable as a substitute. I was also under the impression that engines these days were already "pretested/broken in" to some degree on the bench before assembly. Perhaps not.
Keeping my finger crossed and hoping for the best!! Thanks

You will never see any auto maker to blame as for most the way they do it works acceptably for the vast majority of car buyers. Here in the performance world is about the only place people dig this deep to really understand and get this close to their car. Remember, most use their car for transportation and think of little else.

And the motors are spun on the bench for a partial break-in but for most this is not enough IMHO. Just think how confusing it would be to the 99% of car buyers if they were told to break in a new motor hard and then change conventional break-in oil to full syn at 1000 miles. There would be a revolt! They want to buy a car and out gas in and drive and not think of anything else until a service reminder pops up or a CEL.

And also, GM is far from alone with this....the list is long of most other manufacturers with similar issues. The chrysler hemis are so bad at oil ingestion they come with an integrated oil separator, but it returns the contaminated oil to the crankcase which is a no-no. The mini is a DI engine and talk to a BMW tech.....they have to remove the cylinder heads at 30-50k miles to physically remove the carbon & gunk build-up including a valve job. Allot can be prevented with a good catchcan as far as the most commond ingestion issues.

A suggestion, (very easy) remove your throttle body and look inside your intake manifold with a flash-light and use a clean white paper towel to reach in the snout. Even if you have no noticeable oil consumbtion my guess is you still have damaging ingestion that a can can prevent.

[VR Baron]

Originally Posted by 90503

I too believe this is an area of concern. What I find interesting is how GM instructs what appears to be an incorrect way to break in the engine, as recommending the wrong type of oil! This is amazing and horrible if found to be true.
If so, I don't see how the outcome could be anything but a future class-action lawsuit, and/or a massive recall.

My experience so far, no catch can, only one oil change, no noticeable oil use...First car that's ever had full synthetic...I always believed full synthetic was somewhat of a gimmick to increase rated mpg, and that "regular" oil was perfectly acceptable as a substitute. I was also under the impression that engines these days were already "pretested/broken in" to some degree on the bench before assembly. Perhaps not.
Keeping my finger crossed and hoping for the best!! Thanks

On mine uses dexos semi synthetic. I was told by service manager to leave in for 3000 miles as it did have extra breakin addatives from the factory and wanted to get best use of them. Changed to Mobil1 synthetic and all is good.

[90503]

Originally Posted by VR Baron

On mine uses dexos semi synthetic. I was told by service manager to leave in for 3000 miles as it did have extra breakin addatives from the factory and wanted to get best use of them. Changed to Mobil1 synthetic and all is good.

So let me get this straight...if you have improperly seated rings, you will have noticeabel oil consumption from the dipstick reading, and a lot of oil in catch can, if you have one.
If no catch can and oil consumption...problems in intake...and ???

If no catch can and no noticeable oil use from dipstick...still a problem??

[VR Baron]

Originally Posted by 90503

So let me get this straight...if you have improperly seated rings, you will have noticeabel oil consumption from the dipstick reading, and a lot of oil in catch can, if you have one.
If no catch can and oil consumption...problems in intake...and ???

If no catch can and no noticeable oil use from dipstick...still a problem??

Tracy can answer these as I dont know, yes to #1 on rings I would think but when I checked the dip stick it showed almost full,yet the amount drained out when cold was 7.5 qts out of 8, so I figure not all really drains out.

[SSE 4 2SS]

Originally Posted by 90503

So let me get this straight...if you have improperly seated rings, you will have noticeable oil consumption from the dipstick reading, and a lot of oil in catch can, if you have one. Provided the catch can is properly plumbed... I only say this due to there having been quite a few plumbed in wrongly... but yes...and no.... you may also be burning most of the oil and pushing it out the exhaust... rather than pushing it out the PCV system...This will be obvious after a time due to the oily residue noticeable in the exhaust tips.. The catalytic converter will burn off much of this initially, but eventually it will clog them and rob power due to excessive back pressure and this allows the little bit that does get through to have time to condense and settle within the exhaust pipes.

If no catch can and oil consumption...problems in intake...and ??? If no catch can, and noticeable consumption, then it could be bypassing the rings and burning off directly, or it could be sucked in by the PCV system and you will see pooling oil in the intake by removing the throttle body

If no catch can and no noticeable oil use from dipstick...still a problem??

If you have no noticeable oil loss on the dipstick between changes, then you probably have properly seated rings... The bonus of the catch can is that even in a properly broken in motor, you will have some degree of blow by... pressure leaving the combustion chamber and reaching the crank case...This creates unwanted gases that need to be removed for engine longevity. If you do not have a catch can, you will notice this sludge within the intake manifold by removing the throttle body...

Catch Cans remove this prior to it reaching the intake plenum. Some consumption is normal, and will be seen in a perfectly good engine... excessive amounts is where the problem lies... Improperly seated rings in addition to causing oil consumption also cause substantial power loss and other problems. Excessive carbon buildup on the pistons, plugs, valves etc...loss of power due to less B.M.E.P retained within the combustion chamber...Engine running hotter due to the combustion gases reaching the crank case...etc...

Hope this helps, and If I confused myself and Traci catches it, he can correct me...

[SC2150]

Absolutely correct SSE! This site keeps getting better and better with the more knowledge shared.

[90503]

Originally Posted by SC2150

Absolutely correct SSE! This site keeps getting better and better with the more knowledge shared.

Thanks for all the info. I know this isn't a catch can thread...but then a lot of oil in a catch can would definitely mean bad rings...?

All of the catch cans I've seen are on cars that have also changed the air intake...can one be installed with the stock air cleaner/intake??

Thanks.

P.S. SSE 4 2SS (Sorry about earlier! Couldn't resist! Got my mind right!!) lol