Dangerous Don

Well guys let me start off from the beginning. I went in for my second oil change around 4500 miles (first being the 500 mile break in) I drove the car around for a while and then took a 1k mile road trip from Chicago to New Orleans. When I got back to chicago I decided to check the oil as I never did prior to this and what I found was for the oil level to be about 4 inches above the hash marks....... In my experience that would mean that there was about 4 quarts too much oil in the engine, maybe that's different on these new vehicles though, I'm not sure. So now I have already driven about 3500 miles with way too much oil in the engine, and I brought it in to the dealer the next day as I already had an appointment for them to replace my already warped rotors... I explained to the service writer that I checked the oil and it was about 4 inches above the hash marks and he instantly got an "Oh no" look on his face and told me that he would have the tech check it and remove whatever oil needed to be removed, no problem right? Well I got the car back and stupid me didn't check to see if they drained the oil out, and 500 or so miles later I start to hear some rattling in the valve train on the drivers side but I really couldn't tell if it was just the direct injection or something else but never really paid it any mind as I only really heard it on cold starts which is when the engine is revving high to warm up anyways. The next day I'm driving on traffic and I start getting faint whiffs of burning oil, I just assumed that it someone else in traffic until a good samaritan pulled up next to me and told me that every time I hit the gas there was blue smoke coming out of the exhaust.... Yeah it's me burning the dang oil......in a brand new car.... With less than 10k miles on it... So the next day I bring I back to the dealer and tell them what's going on, that was last Wednesday, I haven't heard back from them so today I called and spoke with a service writer and he went and spoke with the corvette tech who was working on the car. According to the service tech he found 1 of the lifters on the drivers side bank to be damaged, not sure if it was just stuck, or what they meant by damaged, but they're waiting on parts and are replacing all of the lifters on the drivers side.

Now my question for you, I can completely agree that the lifter may have been damaged and could be what was causing the rattling noise I was hearing, but how the heck does that explain the oil burning? And wouldn't there be some sort of collateral damage, damage to the cam, possibly to the valve, valve possibly hit the piston causing it to crack and burn oil? According to the tech there was no other signs of damage yet I have never seen a lifter that failed not cause collateral damage? Any input? Any further steps I should take in getting this resolved? I just don't want them to put it back together and then every couple thousand miles something else breaks because it's damaged but still functioning at the moment....

For everyone who is going to get on me about not checking my oil, just realize that I shouldn't have to check my oil, it's a new vehicle and all service has been performed at the dealer, this is why I have a warranty.

Jim Barker

Too much oil may not be as simple as you think. easier on the dry sump to be over filled than the wet sump. Fuel dilution or antifreeze contamination would be suspect on both systems. A cylinder that so full of either, that it hydraulic locks, can break several engine parts.

Dangerous Don

It is a z51 with a dry sump system which is more or less the reason why I wasn't so much worried about any problems until the car started burning oil. I just don't see how there wouldn't be collateral damage from the lifter failure and I don't see how the lifter alone explains oil consumption?

Jim Barker

Being over full that much the oil is being pulled into intake manifold by the PVC system which is not designed to separate that much oil with high levels. Thats why it is important to find reason for the level to be this high. Seal on high pressure pump or loose or broken high pressure lines they are common to sump with 2200 psi. If it does have bad lifter then thats another issue! A lifter that causes a dead cylinder would dilute the oil but I would think you could tell if a cyl was dead or set a code but an internal leak on fuel system may not until oil pressure loss or fouled plug showed up as misfire

Jim Barker

Sounds like they are changing the bank of lifters that control cylinder deactivation. They can fail and not cause any other damage but some metal from locking pins or possible solenoid failure that controls the lifters.

15Z06

I don't pretend to understand the relationship between burning oil and a lifter going bad, but that was the case in my Avalanche as well. Dealer kept blowing me off because the symptoms were intermittent.

By the time I finally got pissed off enough that they couldn't ignore me any more, the lifter AND cam were both toast. There were no egregious misses and it never coded.

I'm not sure at all that our two issues are related, but a bad lifter does make me wonder about your cam as well. On the other hand, maybe I'm all wet.

tblu92

This has been an issue for GM for many years--failing lifters with the DOD or AFM system
Doesn't matter if it's on a dry or wet sump oil system however on dry sump the problem with oil levels not being accurate after an oil change can make it worse
The reason the lifers fail is that when running on 4 cylinders not only does the spark to those cylinders stop---the fuel to them stop but also the OIL is turned OFF to the hydraulic lifters to prevent the valves from opening---This drastically reduces the lubrication to the lifters !!!!!!!!!!!! It may be they are only getting lubricated by "splash" or by accident---
On all cars/trks I tune , I always recommend turning the AFM/DOD OFF---
My car gets 30 MPH on 8 cylinders and maybe 35 on 4-----So why gamble on reliability for 5 MPG-----
With AFM/DOD it becomes hugely important to get the oil level exactly correct--The recc. oil viscosity correct and the oil temperature correct and to always have fresh clean oil---Any deviation to the "perfect recommended conditions " will possibly show reasons for failures------- This is my opinion from my experience--

\Boost Monkey/

I have heard of oil consumption problems because of cylinder deactivation (depositing into the rings on deactivated cylinders or whatever it was).

Never heard of this. I have never had tuned (or messed with any modules etc at all) a car with cylinder deactivation. How would I go about turning off this feature in the ECM? Can any tuner/tune do it?

tsts

Another question you might ask/research is if your oil changes were performed with Mobile 1 or with Dextos. Not using the recommended oil (Mobile 1) comes with the warning that engine damage might occur if Mobile 1 is not used. Kinda makes me wonder!

\Boost Monkey/

No it won't, don't buy that hype.

Oskee

I too would like to know how to keep my 2015 Z06 in V8 mode only. It even goes in to V4 cruising around town and when I accelerate switches to V8 then at light throttle switches back to V4. It sure would be nice to be able to turn of the AFM !!

bob guzzy

Check your owners manual it will tell you when it will go into 4cyl mode.

Automatic transmission cars do it more often than the 7 speed cars.

hawkgfr

Only way with an automatic is to be in manual shift mode....or tune it out.

EcoBrick Bob

My son who has a G8 GT had lifter issues about a week before his engine warranty ran out. Car only had 29K and had DOD tuned off for almost all of those miles in a Vector Motorsports tune. Fortunately he had the original un-tuned ECM and Dealer & GM replaced all the lifters on both banks under warranty!

It was a DOD lifter that was the issue, even though it never went into DOD mode until he put the original ECM back in.

tsts

Its not hype, its the wording directly out of the owners manual.

\Boost Monkey/

Do some research...

Dexos is no different than say LL-01 from BMW, it's a license type deal of GM recommended oils that have been tested and approved. The company must continually pay a license fee to be approved. Thereby it makes no difference if "A" brand is actually better than "B" brand, because is "B" brand pays the license fee and has been tested and approved, then they are Dexos approved and A brand is not if they choose not to pay the fee.

The only negative to using a non Dexos oil is that if GM finds out it could void your warranty. But, according to the Magnusson-Moss Warranty Act, it is on the shoulders of GM to prove that without a doubt a non Dexos oil damaged your engine, which isn't easy to do. Using the proper synthetic and grade specified of a quality brand oil other than Mobile 1 will not hurt or damage your engine. API standards such as GF-5 (the newest one iirc) are a more non brand specific standard that you want to look for.

Car manufacturer specific oil standardization is nothing new in debate on car forums. If the manual makes you nervous, then use Mobil 1 and don't worry about it.

tblu92

Any local tuner or even a mail order tuner can turn OFF the DOD--Not sure about any of the handheld tuners but I think that the Diablo products may be the only one--

tblu92

I you ever have a chance to view the makings of the DOD valve train you'll notice how complex it is--Even when not in use all the oil still has to pass thru several solenoids and complicated plumbing--By my way of thinking the end result is still less lubrication that the non DOD lifters--The DOD valve train is also heavier
LT1 engine builders who choose to run more aggressive camshafts ALWAYS remove all the DOD lifters solenoids and plumbing hardware
and replace them all with a simple LS7 lifter----Less weight--less moving parts--and better overall lubrication--Also a DOD lifter limits the amount of duration and lift your cam can have---To me it's a weak point whether DOD is used or not--

crazybiker51

Mine is puffing blue now on downshifts and wot pulls, also noticed my car with headers off-road x and tune has less power then stock... Threw a code for a rear O2 ever since tune, which apparently was deleted, tuner looking back into it, but increasingly wondering about the puffs of blue and oil smell when coming to a stop

tblu92

Do you have a "catch can"---- Most all LS and now even the LT engines suffer from the PCV system sucking up oil vapor from the valve covers into the intake manifold via the PCV-- Do some research on here if you have a dry sump--Seems like they have an even more complex issue of "burping" oil vapor on rapid decelerations into the air intake-- At WOT where there is "0" vacuum in the intake manifold the same burping and vapor can be expelled