2012 v6 oil issue

[pjtexas1]

I would also like the info.

[T4JEt]

Originally Posted by Chevrolet Customer Svc

Hello jfcamaro,

I understand your frustrations with the wait and time away from your vehicle. I would like to monitor this situation. If possible, could you private message me your name, VIN#, current mileage and involved dealer information? I will contact your dealer to inquire about the process going forward and follow up with you.

Reggie B.
Chevrolet Customer Care

Yet another reason why I love C5!

[AKA-22]

[SC2150]

I will go through the steps from when the car arrives from the factory:

First, the engine breaking procedure is to reduce warranty and legal claims.....it has nothing to do with breaking in the engine for long trouble free life. If there is a defect, it will show in the first 1000 miles if driven somewhat hard so babying it for 1400 miles is not good.

The cylinders come with a cross hatch hone finish that is somewhat abrasive so the piston rings seat, or wear in properly to the cylinder walls. If driven easy, after the first 100-200 miles the cylinder walls have worn smooth and a hard glaze forms on then so there is little chance the rings have seated in properly and never will. This causes excess blow by and allows oil to be drawn into the combustion chamber on the intake stroke thus oil consumption. In the old days (I have been building engines for almost 39 years) engines came pre-filled with breakin oil thathad enough protection for the bearings and journals but still allowed enough friction to properly seat rings, but it was critical to drain it after 500-1000 miles or engine damage would occur. Now days, buyers want to buy a car and just put gas in the first 10,000 miles so they come prefilled with a good protecting oil that can last that long (it's all marketing). And most never open the hood to ever check fluids ....the manufacturers want all maintanance done by the dealer service centers for reacurring revenue streams.

Then, the PCV systems are not designed to prevent oil mist from being ingested into the intake air charge (cost is to high....the engineers are the best, but have budget constraints so shortcuts are part of every aspect in a cars manufacturing...or we would be paying $200k for a camaro like a ferarri or Lambo which most dont realize the competitive doings between the big 3 here and the imports) and this causes coking on the intake valves:

No fuel travels past the intake valves on todays direct injection engines so this is what the valves look like in 15-20k miles. This wears the valve guides out and then oil is drawn in past the guides adding to the consumption issues (todays top tier fuels do nothing to keep valves clean on DI engines where in the past, port injection sprayed fuel into the intake ports and the additives kept deposits from forming).

Then, as these deposits break loose, some are forced between the piston and cylinder wall causing scouring and further damage that allows even more ingestion:

The picture above is of a piston from a 3.6DI GM engine with 8k miles on it. You can see the side of the piston closest to where the fuel injector spray hits has very little scouring on the skirt....due to very little build up. Now look at the opposite side where you can see scouring that is already compromising the piston from the hard particles breaking off (this engine had 1 upper induction cleaning, which is fine...just dont do it to often):



Then, the engine do not have PCV valves anymore so they have a fixed orfice PCV barb that limits the ability for the engine to evacuate, and this forces oil mist into the clean side inlet again adding to the issue as these small holes clog with buildup:


So, this can only be prevented by breaking the engine in hard the first 500 miles with a good conventional oil, then drain and ONLY use full synthetic, not dexos blend!

And, a GOOD function oil separating catchcan from day one so NO deposits form (and only a few cans are actually worth using, no matter how nice they look or the claims).

Then, the PCV orfice needs to be drilled to 5/64" both the top and the bottom 2 holes, and you will not have these issues.

Now, there are exceptions to the rule and some luck out and dont have excess consumption, but ALL DI motors, no matter what car brand, have the intake valve coking issues.

Hope this helps.

[SC2150]

These are EXCELLENT engines....just amazing in fact, but if you follow the factory break in and do not take the steps pointed out, odds are you will have the ingestion issues. And be aware, in 2014-2015 all v8's will be DI as well.

Now, if you have miles on already, get a good catchcan installed ASAP, do the drill mod, and odds are the consumption will reduce after a few thousand miles as the rings may free back up without the PCV side ingestion. We see that app 70% of the time.

[911medic]

Tracy,

I was hoping you were going to specifically address the timing chain failure issue, not just the general oil consumption issue from improper break in or the DI intake valve coking.

I understand that oil consumption will eventually lead to low oil levels, which contributes to timing chain failures on these engines, but is there a specific design problem that you know of WRT the chains and how they are lubricated?

I was also under the impression that the LFX had improved in this area vs the LLT. Is that not the case in your experience?

Is there anything we can do other than maintain proper oil levels and use full synthetic oil to prevent timing chain problems? Do the LLT and LFX require any different care to avoid this issue, in your opinion?

Thanks for your insight.

[SC2150]

Sure.

LFX & LLT are very similar in this area. There are tons of owners going 100-150k miles w/out issue if cared for properly. These are amazing engines and the only reason there are issues I blame on marketing dictates, not the engineers. They are amoung the best in the world.

The timing chains have a very low profile gear set that is great for less friction, but it is very oil pressure dependant to keep the chain tension where it needs to be (the tensioners have spring back-up, but the oil pressure is critical to keeping proper tension) to prevent "jumping timing" by the chain sliding teeth on the gears, so two things happen. One, use of the lower grade DEXOS approved blend oil results in accelerated chain stretch (only use full syn after break in), and 2, if the engine is run low on oil (as so many do as there is no low oil level indicator) when coming to a stop, or a corner, or acceleration (anything that causes oil in the pan to move from the pick up) can result in the oil pump momentarily sucking air (even if the guage does not show as the guage responds slowly) and then the tensioners allow slack, and the chain can jump teeth. If it jumps more than a few the result is the valves hit the pistons and then catastrophic failure is the result.

So, it is not really a design flaw in the engine itself....it is the marketing politics of the target demographics for a certain model. The V6 camaro is the entry level, lower priced for those that want the looks, but economy and low cost of maintanance are on the buyers mind....so marketing lists 87 octaine (cheap fuel) when 93 the car will run better and get better fuel economy, DEXOS blend oil instead of full synthetic, 10k mile oil changes, etc. so the results are the issues many experiance. I know its hard for alot to grasp what all goes on behind the scenes in auto manufacturing and marketing, but management, marketing, and legal dictate what is disseminated to the public (just look at posts from the GM service reps on forums...all are a canned pre-approved response as it is all so controlled what you the consumer see/here. That should not be taken as not doing a good job to help forum members, in fact we should all appreaciate how they are here to help as much as they are able. They are just very controlled on what they can reply in public), and not what is best for the vehicle and the owner wanting their baby to be the best and last the longest. It is all a balancing act (and one of the most frustrating aspects from the engineer's standpoint) on making these the best within budget restraints and competing aganst the same segment Ford, Crys, the inport's, etc. have offerings in. And this is in ALL production cars and light trucks.....not just GM so owners of other brands have issues as well, so don't abandone such great cars as these are....just get educated )and not misinformation) and get back in touch with your car and its quirks like we all had to in the old days. How many have even tried to check your trans fluid level? (no dipstick, dealer service only). How often do most open the hood and check oil and other fluid levels? We as members here are a miniscule minority of the owners out there. Most never are aware of these issues and trade every few years for a new model. Forum members for the most part want to learn, and get the most enjoyment out of their car....and no matter what motor you get, these are awesome cars period.

Ask any more questions and I will do my best to answer, but none of it will be politically correct....only facts.

[AKA-22]

where is this PCV orfice located?

[911medic]

Originally Posted by SC2150

Ask any more questions and I will do my best to answer, but none of it will be politically correct....only facts.

Thanks Tracy.

[911medic]

AKA-22, on the V6, it is on the rear of the passenger side valve cover. The PCV hose that connects to the intake manifold leads back to it.

I can't speak to the V8.

[SC2150]

V8 LS3 is in the valley cover assy, L99 is the rear of the drivers side valve cover.


The V6 is the one with the issue more than the V8. Most V8's dont have the orfice clog like the V6, and its 7/64" drill....not 5/64ths like I posted earlier.

It comes out pretty easy on the V6, V8 you cant remove it so valve cover has to come off.

On the v6, twist the base with a plyers and pull up and it pops out. Drill, clean, and push back in until fully seated.

Here is a pic of before:

Here is after:

[AKA-22]

Originally Posted by 911medic

AKA-22, on the V6, it is on the rear of the passenger side valve cover. The PCV hose that connects to the intake manifold leads back to it.

I can't speak to the V8.

thanks!

[JohnnyBfromPeoria]

Just as an aside, I broke my engine in the "Tracy Way" and have zero problems at 18K+ miles so far. No oil consumption and very little was showing up in my catch can.

And I check my oil regularly.

John B.

[SC2150]