File in Section:

Service Bulletin

Bulletin No.:
Date:

PIP5029B
September, 2012

PRELIMINARY INFORMATION
Subject:

Engine Misfires Due To Major Carbon Deposits On The Intake And Or Exhaust Valves

Models:

2009 - 2013 Buick Enclave
2009 - 2013 Buick Lacrosse
2008 - 2013 Cadillac CTS, STS
2010 - 2013 Cadillac SRX
2013 Cadillac ATS, XTS
2008 - 2010 Chevrolet Cobalt SS, HHR SS
2009 - 2013 Chevrolet Traverse
2010 - 2013 Chevrolet Camaro, Equinox
2012 - 2013 Chevrolet Impala
2009 - 2013 GMC Acadia
2010 - 2013 GMC Terrain
2007 - 2010 Pontiac Solstice GXP
2009 - 2010 Saturn Outlook
2007 - 2010 Saturn Sky Redline
With any of the Following Direct Injected Gasoline Engines:
2.0 (RPO LNF)
2.4L (RPO LAF, LEA, or LUK)
2.8L (RPO LAU)
3.0L (RPO LF1 or LFW)
3.6L (RPO LFX or LLT)

This PI was superseded to update photo and part numbers. Please discard PIP5029A.

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

Condition/Concern
Some customers may complain of a MIL and engine misfire. In some cases, the misfire may be more apparent on a
cold start, may count on a single cylinder or several cylinders, and may or may not be felt by the driver. Upon
inspection, the technician will find one or more misfire codes (DTC P0300-P0306) stored in the ECM and SI
diagnosis may or may not isolate the cause of the misfire depending on whether the intake/exhaust valves are
sticking at the time of the diagnosis.
This may be the result of major carbon build up on the intake and/or exhaust valves as shown below so the misfires
should not have appeared until at least 5,000 miles or more.

2836273

2836275

2857957

2857954

2857955

2857956

Recommendation/Instructions
If this concern is encountered, perform SI diagnosis. If SI diagnosis isolates a valve sealing concern and/or
eliminates everything else external to the engine, decarbon the engine with Upper Engine and Fuel Injector Cleaner
by following the guidelines below:
Important: Extreme care must be taken not to hydro lock the engine when inducing the cleaner, especially if it is
induced without Kent Moore Tool # J-45076 / J-35800-A or equivalent. If too much cleaner is induced at too low of a
RPM, or if you force the engine to stall by inducing too much cleaner at once, the engine may hydro lock and bend a
connecting rod(s).
1. In a well-ventilated area with the engine at operating temperature, slowly/carefully induce a bottle of GM Upper
Engine and Fuel Injection Cleaner into the engine with RPM off of idle enough to prevent the engine from
stalling (typically around 2,000 RPM or so). Depending on the engine configuration, induce the cleaner through
the throttle body or an engine vacuum hose/pipe. For best results, it is suggested to induce the cleaner through
the throttle body with Kent Moore Tool # J-45076 / J-35800-A or equivalent (shown below).
2. Turn the engine off after inducing the cleaner and allow the cleaner to soak with the engine off for 2.5 to 3 hours
(Do not let cleaner soak for more than 3 hours as remaining deposits may start to harden back up again).
3. Add a bottle of GM Fuel System Treatment Plus to the fuel tank and fill the vehicle with one of the Top Tier
gasolines listed at http://www.toptiergas.com and/or in the latest version of 04-06-04-047 (USA) or 05-06-04-022
(Canada). See Bulletin 05-00-89-078 for more details on GM Fuel System Treatment Plus.
4. Test drive the vehicle extensively to circulate the GM Fuel System Treatment Plus.
5. Re-evaluate the concern to determine if it is repaired or improved at all. If the concern is improved but not
repaired, it may be necessary to perform the above decarboning process a 2nd time.
6. To complete the repairs, advise the customer to only use one of the Top Tier Gasolines listed at http://
www.toptiergas.com and/or in the latest version of 04-06-04-047 (USA) or 05-06-04-022 (Canada) to minimize
future deposits. It can also be recommended to add a bottle of GM Fuel System Treatment Plus at every oil
change as mentioned in the latest version of 04-06-04-051.
Kent Moore Tool Kit # J-45076
1. Pressurized Canister from J-45076 is shown - J-35800-A is similar
2. Throttle Body Cleaning Adapters J-45076-46 and J-45076-55 Shown (Equivalent Adapters Acceptable)

2905424

Parts Information
Part Number

Description

Qty

88861803

Upper Engine and Fuel Injector
Cleaner

1

88861013

Fuel System Treatment Plus

1

Warranty Information
For vehicles repaired under warranty use:
Labor Operation

Description

Labor Time

J7579*

Decarbon Engine Using Upper Engine
Cleaner

0.5 hr

* This is an unique labor operation for bulletin use only. This will not be published in the Labor
Time Guide.

ADDITIONAL SI KEYWORDS: P0301 P0302 P0303 P0304 P0305
Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is
resolved without completing every step, the remaining steps do not need to be performed.