2nd year into production, General Motors revises Corvette C7 Z51 Stingray BREAK IN procedure and first engine oil change interval

With so many fuck ups related to the newest generation of Corvette, this one has to be either on top or very close to the top of the +General Motors corporate bloopers and +Tadge Juechter personal fuck ups.

Well into 2nd year of production, all of the sudden, the great Corvette swami, Juechter finally figured out that the already well advertised GM inability to figure out how much oil goes into LT1 motors should be addressed.  Thus, there is a service bulletin declaring that for all freshly produced Z51 Stingrays, the very first oil change is required at 500 miles, regardless of what the oil life indicator system may be stating.

Now, this is quite a change, certainly a first one for Corvette and not something to be bragging about for sure.

So why this change and will happen to all Z51 Stingrays already produced with more than 500 miles?

The reasons for this dramatic change are not all that hard to figure out:

1. Inadequate PCV causing excessive vacuum drawing engine oil vapors into the intake instead of combustion chamber, a well documented problem, directly related to oil volume present.  GM already tried to eyeball the correct volume, downsizing capacity to 9.8 quarts but apparently none of the UAW Bowling Green crew knows what this means.

2. Already very well documented engine components sloppy machining of the heads, valvetrain and crankshaft, resulting in excessive metal shavings in the oil system and subsequent engine failures.
Yes, this is not a problem caused by "defective oil filter" as Car and Driver tried to claim a while ago, with apparently bullshit blessing from Juechter himself.  However, this problem affects all LT1 engines, not just those equipped with dry sump.  Thus, back to number 1 it is...

So what is GM hoping to accomplish with this first oil change at 500 miles?  500 mile oil change has been a thing of the past for quite a while, at least for mainstream automakers.  This problem was also not present on the previous generation of Corvette engines, including those with dry sump system.  There were problems with system overfilling and oil present in the intake manifold and throttle body, creating job security for the makers of the so called OIL CATCH CAN. 

There is a big distinction here however, the LT1 and LT4 engines use a new PCV integrated system, one that Juechter bragged about at the time of Stingray introduction and the same one that is failing big time, creating considerably more business for the catch can vendors than ever in the past.

The funny part about dry sump oiling system is that the actual capacity is not set in stone, for the severe track duty, the oil capacity can be and should be increased.  However, with the LT1 PCV system, it is the PCV system that sets the limit and in fact, creates a high failure potential for LT1 and LT4 engines exposed to heavy track duties.  Now, the irony of this whole situation is just beautiful, with another "revolutionary" technology becoming performance limiter.

Apparently the problem is so bad that GM decided to require the very first oil change to be done rather quickly, hopefully before the impacts of oil capacity guess work become too obvious, through puddles of oil forming under the car and throttle bodies becoming embalmed in engine oil, both activities requiring pretty intensive warranty work to remedy.

Now, what is really funny here is the official cover story to disguise the real reasons and problems.  According to GM, there are mysterious constituents in silicone sealants used during assembly that somehow migrate from engine gaskets into the engine oil and somehow contaminate the engine oil anti foaming additives, rendering them less effective.

Gotta give Juechter and GM big credit here: for artistic creativity, one that competes with the previously released tale of defective oil filters releasing metal chunks destroying crankshafts.

Certainly, this is some true creativity here, blaming mystery sealants for overfilled oiling systems causing foaming and subsequent loss of oil pressure that certainly does not help already handicapped poorly machined crankshafts and under designed bearings.  The real question here is: what happens to the early adopters who managed to put more than 500 miles on their cars and sell their cars eventually.  Who in their right mind will be buying those ticking time bombs?  What a great way to increase the resale value of these turds, LOL.

2014/2015 Z51 and Z06 Corvettes – Additional Required Maintenance

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Date: 11/24/2014 Ref. number: Service / Service Operations / G_0000205212
Subject: 2014/2015 Z51 and Z06 Corvettes – Additional Required Maintenance

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To: Chevrolet, Buick, GMC, and Cadillac Dealers

2014/2015 Z51 and Z06 Corvettes – Additional Required Maintenance

The following message only applies to dry sump Corvettes that have not had their first oil change performed.
Some 2014/2015 Z51 and Z06 Corvettes may experience a condition that leads to oil leaking out from the air cleaner assembly. This condition may be caused by running the engine continuously at a high engine speed with the first factory fill oil, resulting in silicone sealants in the engine’s gaskets degrading the oil’s anti-foaming agents. The oil foam has no effect on the engine’s durability.

Effective Immediately:

GM is changing the required maintenance schedule for all 2014/2015 Z51 and Z06 Corvettes equipped with dry sump systems. The new schedule will require the oil/filter be changed immediately after the break-in period, which occurs after the first 500 miles of operation. Once the break-in oil change is performed and the Oil Life Monitoring system is reset, customers should follow the Oil Life Monitoring system for all future oil change needs.

The 2nd printing of the 2015 Owner Manuals is being updated with this change. These manuals will not be in the glove box material until January 2015. For vehicles produced before this change, and for all vehicles going forward, it is important to notify the customers that a change has been made, and they will need to have the vehicle’s oil changed after the break-in period. Copies of the new maintenance grid will be available on GMPROGRAMINFO.com, under Chevrolet, Resources.

As you are aware, all 2014/2015 Corvettes come with Chevrolet Complete Care which covers 2 years/24,000 miles of select required maintenance. Previously, up to 4 service events were allowed under the program guidelines in the 2-year/24,000-mile period. With the change in the maintenance schedule being effective immediately, an additional oil change allowance will be added to 2014/2015 Z51 and Z06 Corvettes, increasing the amount of coverage to 2 years/24,000 miles, up to 5 service events.