Bulletin No.: PIP5661A
Published date: 10/31/2019

Preliminary Information
PIP5661A 2019 2.0 LTG Engine Runs Rough with Malfunction Indicator Lamp (MIL) ON,
Low Compression on Cylinder with Mis re, DTC P0300 Set
Models
Brand:

Model:

VIN:

Model Years:

from

to

Engine:

Transmissions:

Buick

Envision

2019

All

All

2.0 LTG

All

Buick

Regal

2019

All

All

2.0 LTG

(AWD Only)

Cadillac

ATS

2019

All

All

2.0 LTG

All

Cadillac

CTS

2019

All

All

2.0 LTG

All

Chevrolet

Camaro

2019

All

All

2.0 LTG

All

Chevrolet

Traverse

2019

All

All

2.0 LTG

All

Involved Region or Country North America
Condition

Some customers may comment on a rough running engine with the Malfunction Indicator Lamp (MIL) ON. Upon
inspection, a technician may nd DTC P0300 mis re set and may nd low compression in one or more cylinders. This
condition may be caused by spark plug carbon tracking and/or a crack in a piston located between the piston compression
rings.

Cause

Ignition coil and spark plugs with carbon tracking damage can lead to increased mis re events and ultimately damage the
pistons and engine assembly.

Correction:
This document assists the technician with diagnosis and repair of a mis re for speci c scenarios as follows:

Scenario #1 - Mis re being caused by spark plug carbon tracking.
Correction - Replace all four spark plugs, all four ignition coils, apply dielectric grease (19260901 USA / 19260902 Canada) to the spark plug boots and
check grounds G120 and G130.

Scenario #2 - Mis re is being caused by a damaged piston and the cylinder wall is damaged.
Correction - Replace the engine assembly (engine comes with spark plugs), all four ignition coils (apply dielectric grease 19260901 USA /
19260902 Canada to the spark plug boots), the fuel injector of the cylinder(s) that had damaged pistons and other components necessary when an
engine assembly is installed.

Scenario #3 - Mis re being caused by a damaged piston and the cylinder wall is not damaged.
Correction - Replace all four spark plugs, all four ignition coils (apply dielectric grease 19260901 USA / 19260902 Canada to the spark plug boots), the fuel
injector of the cylinder(s) that had damaged pistons, all four piston kits, all ring sets for all four pistons, all rod bearings, all four connecting rod
assemblies and other components necessary when pistons are replaced.
If the mis re concern is not resolved after following service information, perform the following diagnosis and repairs.
Visually inspect all the spark plugs for signs of carbon tracking on the portion of the spark plug being covered by the coil boot.

All four spark plugs and ignition coils must be replaced in any of the three scenarios to prevent future failures.
Important: Be sure to apply dielectric grease (19260901 USA / 19260902 Canada) to the spark plug boots as directed in SI for ignition coil replacement.

Apply a thin coating of dielectric grease (19260901 USA / 19260902 Canada) to the inside of the ignition coil rubber boot, up to a depth of 15 mm from
the end of the boot.
Remove any excess grease from around the end of the boot, and ensure there is not an excessive amount within the boot.
Check grounds G120 (item#2) and G130 (item#1) for proper torque and verify the ground eyelets can not be rotated under the bolt.

If no spark plug carbon tracking is seen, perform a cylinder leak down test on the a ected cylinder(s) making sure the mis re is caused by piston leakage
and leakage into the crankcase. Refer to Cylinder Leakage Test in SI.
Check all cylinder wall condition. Some light vertical marks may be visible on the cylinder wall. In these areas, check that the cross hatch marks are still
visible in this marked area. If they are, the cylinder surface has not been compromised and the engine block can be used. If you can catch your ngernail
on anything on the cylinder wall, the engine assembly must be replaced.
If any of the cylinder walls are damaged, replace the engine assembly (engine comes with spark plugs), replace all four ignition coils (apply dielectric
grease 19260901 USA / 19260902 Canada to the spark plug boots), the fuel injector of the cylinder(s) that had damaged pistons and other components
necessary when an engine assembly is installed.
Thoroughly inspect the intake manifold and catalytic converter for any ne metal material that may have migrated there. Replace component(s) as
necessary.
If the cylinder walls are not damaged, remove the pistons and inspect for a fractured piston between the top and second rings.
The pictures below are some examples of what might be found.

If cylinder walls are not damaged and one or more of the pistons are found fractured, replace all four spark plugs, all four ignition coils (apply dielectric
grease 19260901 USA / 19260902 Canada to the spark plug boots), the fuel injector of the cylinder(s) that had damaged pistons, all four piston kits, all
ring sets for all four pistons, all rod bearings, all four connecting rod assemblies and other components necessary when pistons are replaced.
Note: When installing pistons, make sure to use the tapered ring compressor J-43953 special tool. Use care when installing the piston assemblies into the
cylinder so the rings are not damaged.

Recommended Fuel
Do not use any fuel labeled E85 or FlexFuel. Do not use gasoline with ethanol levels greater than 15% by volume.
Premium unleaded gasoline meeting ASTM speci cation D4814 with a posted octane rating of 93 is highly recommended for best performance and fuel
economy.
GM recommends the use of TOP TIER Detergent Gasoline to keep the engine clean, reduce engine deposits, and maintain optimal vehicle performance.
Look for the TOP TIER Logo or see www.toptiergas.com for a list of TOP TIER Detergent Gasoline marketers and applicable countries.

Warranty Information
The correction for this concern may be one of several repairs. For vehicles repaired under warranty, please use the appropriate warranty labor operation
based on the actual cause and repair.

Version History
Version
Modi ed

2
07/17/2019 - Created
10/07/2019 - added part number and changed verbiage in the cause section.

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