PIP5104B

Bulletin No.: PIP5104B
Date: Feb-2016
Subject:
Cold Engine Tick Noise That May Last Up To 50 Seconds
Models:
2009-2013 Cadillac Escalade Models
2009-2015 Chevrolet Express, Silverado, Suburban
2009-2015 GMC Savana, Sierra, Yukon, Yukon XL
With any of the following V8 Engine RPO Codes: 6.0L - L76, L96, LC8, LY6, 6.2L- L94 L9H
This PI was superseded to update Model Years. Please discard PIP5204A.
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Condition/Concern
You may have a vehicle with a concern of cold engine tick noise.
This concern will diminish within 50 seconds of a cold start.
The noise shuts off like you have flipped a switch.
This concern may be a vehicle design characteristic as the ECM calibration is designed to meet coldstart emissions.
The noise that you hear is actually combustion taking place in the exhaust manifold. When the timerhits the 50 seconds it advances the timing and the noise is
immediately gone.
Recommendation/Instructions
Be sure to determine if the tick noise is possibly coming from the exhaust manifold, as this noisecould easily be mistaken for an engine tick noise.
If your SI diagnosis does not isolate the cause of this concern, and all of the following statementsapply, this concern should be considered a vehicle design
characteristic of the ECM calibration andno additional repairs should be performed:
1.
The concern has been present since the vehicle was new.
2.
The concern is greatly improved or eliminated if the engine is allowed to warm up for 1 minute.
3.
The concern is present on a similarly equipped vehicle.
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.
GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may
occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools,
safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that
your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information.
WE SUPPORT VOLUNTARY TECHNICIAN CERTIFICATION
1

Bulletin No.: PIP5104B
Date: Feb-2016
Subject:
Cold Engine Tick Noise That May Last Up To 50 Seconds
Models:
2009-2013 Cadillac Escalade Models
2009-2015 Chevrolet Express, Silverado, Suburban
2009-2015 GMC Savana, Sierra, Yukon, Yukon XL
With any of the following V8 Engine RPO Codes: 6.0L - L76, L96, LC8, LY6, 6.2L- L94 L9H
This PI was superseded to update Model Years. Please discard PIP5204A.
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Condition/Concern
You may have a vehicle with a concern of cold engine tick noise.
This concern will diminish within 50 seconds of a cold start.
The noise shuts off like you have flipped a switch.
This concern may be a vehicle design characteristic as the ECM calibration is designed to meet coldstart emissions.
The noise that you hear is actually combustion taking place in the exhaust manifold. When the timerhits the 50 seconds it advances the timing and the noise is
immediately gone.
Recommendation/Instructions
Be sure to determine if the tick noise is possibly coming from the exhaust manifold, as this noisecould easily be mistaken for an engine tick noise.
If your SI diagnosis does not isolate the cause of this concern, and all of the following statementsapply, this concern should be considered a vehicle design
characteristic of the ECM calibration andno additional repairs should be performed:
1.
The concern has been present since the vehicle was new.
2.
The concern is greatly improved or eliminated if the engine is allowed to warm up for 1 minute.
3.
The concern is present on a similarly equipped vehicle.
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.
GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may
occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools,
safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that
your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information.
WE SUPPORT VOLUNTARY TECHNICIAN CERTIFICATION
1