PIP4959G
Service Bulletin Details
Public Details for: PIP4959G
This preliminary information communication provides information to the technician with information regarding high misfire rates always on #1 cylinder. A customer may complain of misfires or roughness on cold start up with a P0300 diagnostic
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Models from 2018
| 2018 CADILLAC ATS |
| 2018 CADILLAC XTS |
| 2018 CHEVROLET IMPALA |
Models from 2017
| 2017 BUICK ENCLAVE |
| 2017 CADILLAC ATS |
| 2017 CADILLAC XTS |
| 2017 CHEVROLET EQUINOX |
| 2017 CHEVROLET IMPALA |
| 2017 CHEVROLET TRAVERSE |
| 2017 GMC ACADIA |
| 2017 GMC TERRAIN |
Models from 2016
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Models from 2011
| 2011 BUICK ENCLAVE |
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| 2011 CADILLAC SRX |
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| 2011 CHEVROLET EQUINOX |
| 2011 CHEVROLET TRAVERSE |
| 2011 GMC ACADIA |
| 2011 GMC TERRAIN |
Models from 2010
| 2010 BUICK ENCLAVE |
| 2010 BUICK LACROSSE |
| 2010 CADILLAC CTS |
| 2010 CADILLAC SRX |
| 2010 CHEVROLET CAMARO |
| 2010 CHEVROLET EQUINOX |
| 2010 CHEVROLET TRAVERSE |
| 2010 GMC ACADIA |
| 2010 GMC TERRAIN |
Models from 2008
| 2008 GMC ACADIA |
Models from 2007
| 2007 GMC ACADIA |
Bulletin No.: PIP4959G Published date: 12/11/2017 Preliminary Information PIP4959G Cold Start Misfires Models Brand: Model: Model Years: VIN: from Engine: to Transmissions: Buick Enclave 2009 - 2017 All All 3.6L LLT All Buick LaCrosse 2009 - 2016 All All 3.0 LF1, LFW, 3.6 LFX, LLT All Cadillac ATS 2013 - 2018 All All 3.6 LFX, LF4 All Cadillac CTS 2010 - 2015 All All 3.0 LF1, LFW, 3.6 LF3, LFX, LLT All Cadillac SRX 2010 - 2015 All All 2.8 LAU, 3.0 LF1, 3.6 LFX, LLT All Cadillac XTS 2013 - 2018 All All 3.6 lf3, LFX All Chevrolet Camaro 2010 - 2015 All All 3.6 LFX, LLT All Chevrolet Caprice PPV 2012 - 2014 All All 3.6 LFX All Chevrolet Captiva Sport 2012 - 2014 All All 3.0 LF1, LFW All Chevrolet Colorado 2015 - 2016 All All 3.6 LFX All Chevrolet Equinox 2010 - 2017 All All 3.0 LF1, LFW, 3.6 LFX, LLT All Chevrolet Impala 2012 - 2018 All All 3.6 LFX All Chevrolet Traverse 2009 - 2017 All All 3.6 LLT All GMC Acadia 2007 - 2017 All All 3.6 LLT All GMC Canyon 2015 - 2016 All All 3.6 LFX All GMC Terrain 2010 - 2017 All All 3.0 LF1, LFW, 3.6 LFX, LLT All Supersession Statement This PI was superseded to update Models and Model Years. Please discard PIP4959E. The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI. Condition / Concern A customer may complain of misfires or roughness on cold start up. There may also be a P0300 code. For this PI to apply the misfires will be limited to 1 or 2 cylinders. Recommendations / Instructions Misfires on start up only with high miss fire rates always on one cylinder can be suspect for coolant entry at the liner to deck face casting. To inspect for this concern, add coolant dye to the system, run engine through warm up, pressurize the cooling system on a cold soak engine(after being warmed up to operating temperature) and inspect the suspect cylinder with a borescope for coolant dye evidence. At times it may be necessary to remove the head for inspection. 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. 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. See pictures below for examples of deck pitting and actual porosity with leak path. 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. Engine replaced for subject pitting conditions will be returned to the dealership as non defective. The photo above is an example of what true porosity is. Location: # 5 at the 10:00 o’clock position. Cylinder deck face to cylinder liner interface location can cause a leak path into the cylinder for rapid large counts of misfires when cold. Such Porosity is rare, therefore technicians should inspect the subject cylinder and look for a break in the carbon ring. Usually if porosity is present there will be a break in the carbon ring. Coolant present in a cylinder cleans the area of entry and can be found by wiping the carbon ring dry with a clean soft towel, exposing the leak path. Only if true porosity is found would engine replacement become necessary. Call PQC per the latest version of 16-NA-338, if required, reference this PI and replace the engine, ONLY in cases where porosity has been found to be the cause. Warranty Information For vehicles repaired under warranty, use: Labor Operation Description Labor Time 4067490 Engine Replacement Use Published Labor Operation Time 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. © 2016 General Motors. All Rights Reserved.