Most common 2018 GMC Sierra 2500 problems
Share of the 35 complaints; one complaint can involve more than one system. "~" is the median mileage when the problem started.
GMC Sierra 2500 complaints by model year
Best Sierra 2500 years: 2012, 2014, 2013. Years to avoid: 2024, 2025, 2020, 2021, 2022. Compare all years →
2018 GMC Sierra 2500 recalls (5)
Air bags › Side/window › Curtain › Inflator
General Motors, LLC (GM) is recalling certain 2018 Chevrolet Silverado 1500, GMC Sierra 1500, 2018-2019 Chevrolet Silverado 2500, 3500, and GMC Sierra 2500, 3500 Crew Cab trucks. The left or right-side roof-rail air bag (RRAB) inflator end cap may detach from the inflator or the inflator sidewall may rupture.
Remedy: Dealers will replace the left and right side RRAB modules, free of charge. Owner notification letters were mailed November 8, 2024.
Fuel system, diesel › Storage › Tank assembly
General Motors, LLC (GM) is recalling certain 2017-2019 Chevrolet Silverado 2500, 3500, and GMC Sierra 2500, 3500 vehicles equipped with a dual fuel tank option. The rear fuel tank may collapse and prevent the fuel pump from transferring fuel to the front tank, resulting in an engine stall.
Remedy: Dealers will inspect the fuel tank and fuel pump module, replacing them as necessary. Dealers will also add a vent hose to the rear tank assembly. Repairs will be performed free of charge.
Equipment › Electrical › Engine block heater
General Motors, LLC (GM) is recalling certain 2017-2019 Chevrolet Silverado 2500, 3500 and 2017-2019 GMC Sierra 2500 and 3500 vehicles equipped with a Duramax diesel 6.6 liter engine and an optional engine-block heater cord.
Remedy: Dealers will replace engine block heaters and heater cords. Vehicles that have this feature disabled as a remedy to the safety condition will be contacted and offered replacement block heaters and heater cords under a…
Engine
General Motors LLC (GM) is recalling certain 2019 Chevrolet Silverado 4500, 5500 and 6500 vehicles and 2017-2019 Chevrolet Silverado 2500 and 3500 vehicles and GMC Sierra 2500 and 3500 vehicles equipped with Duramax 6.6 liter diesel engines and an optional engine-block heater.
Remedy: GM will contact owners, dealers will replace the engine block heater, free of charge. Additionally, in Chevrolet Silverado 2500 and 3500 vehicles, dealers will install a new rerouted heater cord.
Seat belts › Front › Retractor
General Motors (GM) is recalling certain 2017-2018 Chevrolet Silverado 2500 and 3500 and GMC Sierra 2500 and 3500 trucks. The front seat belt retractor assemblies were built with the incorrect torsion bar.
Remedy: GM will notify owners, and dealers will replace both front seat belt retractor assemblies, free of charge. The recall began March 24, 2021.
What 2018 GMC Sierra 2500 owners say
Engine & cooling
Constant issues with glow plug failures, fuel rail failure, fuel pressure failure. Truck has been in the Gmc service regarding these issues constantly for the last year with a total of five repairs and replacement of glow plugs with releaning learning new plugs and now the 6th return to the shop they're tearing down the fuel system. Malfunction and engine light consistently come on with the same occurring problems generating from the fuel system and glow plugs. Fuel mileage is absolutely terrible and lose of power hazardous to safety!!! Gmc has issued an extended warranty for 15 years and 150,000 miles, but cant and hasn't found a repair for vehicle and just replaces the glow plugs just so they can fail again and again!!! They need to replace everything that needs to be done and if no fix they need LEMON Law The vehicle. …
GM Duramax L5P diesel engine electrical connector for #4 fuel injector. This failure caused the Diesel exhaust brake, which controls downhill speed, to disengage, extreme shaking of the vehicle, emissions system warning and speed limiting. This occurred while descending a steep grade while towing a 34 feet long, 10,000 pound trailer. This is a known issue with this diesel engine and documented in GM Technical Service Bulletin 23-NA-027. Inspection and repair at a GM dealership confirmed a known issue with the #4 injector pigtail connector caused by improper wire routing and interference wit the Sound Shield and Valve Cover Heat Shield This was a sudden failure of the #4 pigtail connector with no advance warning. …
Electrical system
GM Duramax L5P diesel engine electrical connector for #4 fuel injector. This failure caused the Diesel exhaust brake, which controls downhill speed, to disengage, extreme shaking of the vehicle, emissions system warning and speed limiting. This occurred while descending a steep grade while towing a 34 feet long, 10,000 pound trailer. This is a known issue with this diesel engine and documented in GM Technical Service Bulletin 23-NA-027. Inspection and repair at a GM dealership confirmed a known issue with the #4 injector pigtail connector caused by improper wire routing and interference wit the Sound Shield and Valve Cover Heat Shield This was a sudden failure of the #4 pigtail connector with no advance warning. …
I have a 2018 GMC Sierra Duramax Quad-Cab and when it is connected to either my boat, stock trailer, or cargo trailer the lights and electric trailer brakes on the trailers do not work. and the chime from the "Service Trailer Brake" indicator sounds and doesn't stop until I unplug my trailer harness from my truck making it a distraction and an unsafe situation when trying to navigate through traffic(changing lanes, stopping, and other functions needed when hauling trailers). The dealership said it was a module and specified which one and so I elected to replace it myself and it wasn't the issue. I choose to do the work myself as they quoted me a price of $700.00+ to repair the problem.
Fuel & propulsion system
The contact owns a 2018 GMC Sierra 2500. The contact stated that while driving at an undisclosed speed, the vehicle lost motive power. No warning light was illuminated. The vehicle was towed to the dealer, where it was determined that the fuel pump control module needed to be replaced. The vehicle was not repaired. The manufacturer was made aware of the failure and a case was opened. The failure mileage was approximately 48,000.
Constant issues with glow plug failures, fuel rail failure, fuel pressure failure. Truck has been in the Gmc service regarding these issues constantly for the last year with a total of five repairs and replacement of glow plugs with releaning learning new plugs and now the 6th return to the shop they're tearing down the fuel system. Malfunction and engine light consistently come on with the same occurring problems generating from the fuel system and glow plugs. Fuel mileage is absolutely terrible and lose of power hazardous to safety!!! Gmc has issued an extended warranty for 15 years and 150,000 miles, but cant and hasn't found a repair for vehicle and just replaces the glow plugs just so they can fail again and again!!! They need to replace everything that needs to be done and if no fix they need LEMON Law The vehicle. …
Frequently asked questions
Is the 2018 GMC Sierra 2500 a good car?
Based on 35 owner complaints filed with NHTSA, the 2018 Sierra 2500 rates average: 1.3× as many complaints as a typical year of the Sierra 2500 at the same age. Complaint counts don't account for sales volume or individual maintenance, so have any used car inspected before buying.
What is the most common problem with the 2018 GMC Sierra 2500?
The engine & cooling — 8 complaints, 23% of all complaints for this model year. Next are the electrical system (7) and fuel & propulsion system (6).
How many recalls does the 2018 GMC Sierra 2500 have?
There are 5 recalls for the 2018 GMC Sierra 2500, the most recent from October 10, 2024 (inflator). Recall repairs are free at any authorized dealer — check whether yours has been done with the VIN recall check.
What are the best and worst years of the GMC Sierra 2500?
The best years by complaints, compared at the same age, are 2012, 2014 and 2013. Years to avoid or approach with caution: 2024, 2025, 2020, 2021 and 2022. See the full GMC Sierra 2500 years comparison.
At what mileage do 2018 GMC Sierra 2500 problems happen?
The median mileage reported in complaints is about 12,000 miles; 100% of problems with a recorded mileage started before 50,000 miles.
Source: U.S. National Highway Traffic Safety Administration (NHTSA) — owner complaints through October 20, 2026, recalls and defect investigations; fuel economy from the EPA. Complaints are unverified reports and are not proof of a defect. How we rate model years.