Bulletin No.: 25-NA-054

Service Bulletin

Date: March, 2025

INFORMATION
Subject:

Brand:

Information on No Crank, Engine Will Not Rotate, No Start after Traveling in
Cold Weather
Model:

Chevrolet

Silverado 2500HD/
3500HD

GMC

Sierra 2500HD/
3500HD

Involved Region or Country

Model Year:
from

to

2024

2025

Build Date:
from

Engine:

Transmission:

to

L5P

North America, Israel, Palestine, Middle East
Some customers may comment on one or more of the following concerns:
• No Crank

Condition

• Engine will not rotate
• No Start after traveling in cold weather
Some technicians may comment on finding the starter fuse open.

Cause

This condition may be caused by ice in the cylinders.

Information

If the vehicle has been experiencing any of the above concerns, refer to the Service
Procedure.

Important: Service agents must comply with all International, Federal, State, Provincial, and/or Local laws
applicable to the activities it performs under this bulletin, including but not limited to handling, deploying,
preparing, classifying, packaging, marking, labeling, and shipping dangerous goods. In the event of a
conflict between the procedures set forth in this bulletin and the laws that apply to your dealership, you
must follow those applicable laws.

Service Procedure
Important: Do Not rotate the engine in a counterclockwise direction using the balancer bolt. If the torque on
this joint is changed, the engine may experience a loss of oil pressure. Remember that the torque on this
bolt is what keeps the oil pump drive gear from rotating on the crankshaft.
Note: Do Not allow the vehicle to sit over a weekend.
1. Bring the vehicle into the shop to warm up overnight.
2. Check for any glow plug related codes.
• If found, remove that glow plug. If you find a glow plug tip missing, chances are that the glow plug was hit by
ice in the cylinder. Remove the cylinder head to retrieve the tip prior to starting the engine. While the cylinder
head is off, measure the piston projection to determine if a rod was bent.
• If no glow plug codes are set, remove #3 glow plug. Rotate the engine and expel any water in the cylinder. If
the engine will not rotate all the way around, remove the remaining glow plugs and repeat.

Copyright 2025 General Motors. All Rights Reserved.

Page 2

March, 2025

Bulletin No.: 25-NA-054

3. Install new glow plugs and change the engine oil.
4. Remove the charge air cooler to drain any water.
5. Start the engine and evaluate it:
• If the engine runs a little rough, a short test drive is recommended prior to diagnosis.
• If you have a concern that there may be damage due to a hydrolock condition, a relative compression test can
be performed.

6860441

The graphic above is an example of a relative compression test performed on an engine that had a bent piston rod
(Fuel System Disabled, Amp Clamp on 1000 A Setting).
It has been observed that an increase of vehicles has been arriving at the dealer with water or ice in the throttle
body, in cylinders, or in the oil pan. There are two key actions that can prevent this from happening in the future:
1. After a long drive in cold weather, it is recommended to idle the engine for 10 -15 minutes prior to turning the
engine off. This will give time for any ice accumulated in the engine to thaw and get harmlessly consumed by
the engine. If you prefer, turn off the engine and immediately hit the remote start button. The engine will turn off
after 15 minutes of running.
2. Use of the winter front cover. Every 6.6L Duramax powered vehicles is shipped with a winter cover under the
rear seat. Here are some usage guidelines for the use of the winter front cover found in the diesel supplement.
− The winter cover should only be used while operating the vehicle in cold temperatures or in heavy snow. In
these temperatures, the vehicle does not need a large amount of air to properly cool the engine. When more
airflow is required to cool the vehicle, the winter cover should not be used. The following usage guidelines will
allow adequate airflow for proper radiator and air cooler performance.
• Do not use the winter cover if towing a trailer in conditions above 0 °C (32 °F). The vehicle may overheat if the
radiator is covered while towing.
• Do not use the winter cover if a snowplow is mounted on the truck.

Bulletin No.: 25-NA-054

March, 2025

Page 3

If Ice/water is found in a cylinder, there is likely one of two causes:
1. When running without the winter front, ice can form in the intake manifold and or EGR system. When the engine
is turned off immediately after a long drive, the ice will melt and fall into the engine. Once the water freezes, it
will not damage the engine. It is water sitting in the cylinder for a long time that will damage an engine. It is not
recommended to bring a vehicle inside to thaw. Overnight should be enough time.
2. If you find an air filter that has evidence of being wet or if you find water tracks on the induction, the vehicle may
have suffered from snow ingestion. In this instance the CAC should be drained of water prior to running the
vehicle.
Upon viewing the inside of an engine that has suffered from one of these conditions, care must be taken to not
overreact to the looks of the inside of the engine. Surface rust on the inside of a cylinder will not cause an issue with
the durability of the engine. Pitting will.

Version

1

Modified

Released March 07, 2025

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.

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