Bulletin No.: PIP5498A
Published date: 06/14/2017

Preliminary Information
PIP5498A SES Lamp P050D P0300 Setting On A Cold Start And/Or a Run Rough Warm with No codes
Models
Brand:

Model:

Model Years:

VIN:
from

Engine:

to

Transmissions:

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

5.3L L83

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 Options (RPO)

N/A
A vehicle may have a concern of DTC P050D setting along with a P0300 after a cold start up.

Condition

White smoke and/or coolant odor may come from exhaust for an extended period of time at cold start as
well.
It may also Run rough when warm, slight knock, no codes setting.

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 for coolant 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.
This could be the cause of a running rough warn concern with or without codes.
The location of where the coolant is running down in the port will also look washed down.

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 that you 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 16-NA-338, 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.

Version History
Version

2

Modified

6/14/2017 Updated Concern Information

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