Fuel pump whine on GM diesel engines — Bulletin 18-NA-10

Here’s what causes the fuel pump whine and hard start on GM diesel engines

GM has issued a service bulletin #18-NA-103 to address a fuel pump whine issue and hard start on their 2010-20 diesel vehicles. The fuel pump whine may also be accompanied by the following trouble codes:

P0087 Fuel Rail Low Pressure
P018B Fuel Pressure Sensor Performance
P228A Fuel Pressure Regulator 1 Control – Forced Engine Shutdown
P228B Fuel Pressure Regulator 2 Control – Forced Engine Shutdown
P2635 Fuel Pump Flow Performance

Cause of fuel pump whine

GM has determined that the cause of the noise and hard starting and the listed trouble codes is caused diesel fuel gelling in cold temperatures. GM warns NOT to replace the pump to cure this problem. It is not caused by a bad pump

Background on diesel fuels

You should always use the fuel rated for temperatures in your climate. Do not let summer diesel fuel sit in your tank during extreme cold cycles without adding a winter fuel anti-waxing or icing additive.

The anti-gelling additive you use must not contain any metal-based additives, alcohol, or other water emulsifiers. Those components can compromise the operation of the water removal effectiveness of the fuel filtering system.

Diagnose diesel fuel pump whine and hard start due to fuel gelling

Bring the vehicle inside and allow it to warm to more than 0°C (32°F). This may take up to several hours. Then try starting the engine. Monitor the fuel temperature sensor data on a scan tool. If the engine starts, drain the water separator at the bottom of the fuel filter.

If the sound is gone, the problem was caused by the fuel.

How to prevent diesel fuel gelling

Preventing diesel fuel gelling is critical to preventing fuel pump whine

• Use winter or cold-weather blended diesel fuel – These blends include additives that lower the gelling point of diesel fuel making it harder to gel.
• Add anti-gelling additives – Products with names like Howes Lubricator or Power Service not only help prevent gelling but can treat gelled fuel. Follow dosage instructions.
• Install a fuel heater – Heating the fuel tank and lines electrically helps prevent wax crystals from forming. Used in very cold climates.
• Replace summer fuel filters – The small openings get clogged quickest in winter. Changing to new filters gives wax crystals space to flow through.
• Frequently use vehicle – Keeps fuel circulating and warm. Cold unused fuel is most prone to gelling.
• Prevention is ideal, but using additives, heating fuel, and proper maintenance can treat and reduce gelled diesel problems during frigid weather. Let the vehicle run a while if already gelled.

©, 2021 Rick Muscoplat