2016 - 2017 Corvette: Service Bulletin: #PIP5498: SES Lamp P050D P0300 Setting On A Cold Start

#PIP5498: SES Lamp P050D P0300 Setting On A Cold Start - (May 18, 2017)

Subject:

SES Lamp P050D P0300 Setting On A Cold Start

Brand:	Model:	Model Year:		VIN:		Engine:	Transmission:
Brand:	Model:	from	to	from	to	Engine:	Transmission:
Cadillac	CTS-V	2016-2017		All	All	6.2L LT4	All
Cadillac	Escalade	2015-2017		All	All	6.2L L86	All
Chevrolet	Camaro	2016-2017		All	All	6.2L LT1 LT4	All
Chevrolet	Corvette	2016 - 2017		All	All	6.2L LT1 LT4	All
Chevrolet	Silverado 1500	2014-2017		All	All	4.3L, 5.3L, 6.2L L83, L86, LV1, LV3	All
Chevrolet	Suburban	2015-2017		All	All	5.3L L83	All
Chevrolet	Tahoe	2015-2017		All	All	4.3L, 5.3L, 6.2L L83, L86, LV1, LV3	All
GMC	Sierra 1500	2014-2017		All	All	4.3L, 5.3L, 6.2L L83, L86, LV1, LV3	All
GMC	Yukon Models	2015-2017		All	All	5.3L, 6.2L L83, L86	All

*Involved Region or Country*	North America
*Additional RPO/s:*	N/A
*Condition*	A vehicle may have a concern of DTC P050D setting along with a P0300 after a cold start up. White smoke and/or coolant odor may come from exhaust for an extended period of time at cold start as well.
*Cause*	Coolant getting into the cylinders

Correction

If service information for the P050D does not isolate the concern the following may be helpful.

Misfires on start up only, with high rates always on one cylinder, can be suspect forcoolant entry at the liner to deck face casting or the casting line in the intake port of the cylinder head.

To inspect for this concern, add coolant dye to the system, run engine through warm up, pressurize the cooling system after warming the engine to operating temperature (let the engine cool overnight) and inspect the suspect cylinder with a borescope for coolant dye evidence.

At times it may be necessary to remove the head for inspection.

If the head casting line is the concern the intake port will be wet with a coolant oil mix.

If this is found the cylinder head will need to be replaced.

For coolant entry at the liner to deck face casting of the cylinder bore.

It is hard to see the actual source (pin hole) but it usually streams down the liner so thatyou can see it with a borescope.(Sometimes) The top of the piston will be steam cleaned.

Do not confuse residual fuel on the piston crown / surface as coolant. Some fuel residue may be present and can be mistaken as coolant (reason for the cooling system Dye to be added). Use black light to confirm the liquid is coolant. If this concern is present, do not replace the cylinder head because that will not repair this concern. Call PQC per the latest version of 02-07-30-029, if required, reference this PI and replace the engine.

Small surface pock marks or pitting appearance on the deck surface is normal and engines should not be replaced for such appearance as they do not connect to coolant passages and cause a leak path that generate engine misfires. During engine warranty analysis studies, engines are being replaced for small pitting in the deck face as described above, when the subject cylinder / piston is saturated with fuel and not coolant

Engines replaced for light / shallow pitting conditions will be returned to the dealership as non-defective.