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EnginePart report

2018 GMC Sierra 2500 Engine Problems

Complaints
8about this part
Share
23%of 35 total for the year
Median mileage
5,641miles
Trend
Not enough dataFewer than 15 complaints, too few for a reliable trend.

NHTSA recorded 8 complaints about the engine of the 2018 GMC Sierra 2500, 23% of the 35 complaints for this model year. Where a mileage was given, the median is 5,641 miles. 1 recall campaign on record is filed under a similar system.

Fewer than 15 complaints name this part, so treat the figures as a rough indication only.

Example complaints

Selected from NHTSA records; personal details are removed. They are consumer reports, not findings.

“Faulty pigtail connector for fule injectors. Cause The vehicle to shut down even while going down the highway possibly causing injury by immediate deceleration wich could cause an accident. For me on this vehicle I’ve had this happen three times and it has cost me anywhere from $800 to 1000 per injector especially if damage is done to one of the fuel injectors.”

NHTSA complaint #11460968, filed 2022-04

“Low coolant warning light came on. I was towing a travel trailer on a very busy roadway with no place to pull off while pulling a trailer. I had to pull over to the shoulder to check the coolant level and make sure I didn’t cause major damage to my engine by letting it overheat. While waiting to let the engine cool down, I researched and found that this is a very common issue with L5P Duramax Engines in GM trucks and it is specifically related to a faulty coolant level sensor. As it turns out, my coolant level was fine and there was no issue. …”

NHTSA complaint #11524351, filed 2023-05

“The contact owns a 2018 Gmc SIERRA 2500. While driving 30-50 MPH up a hill, the vehicle shuddered. There were no warning indicators illuminated. The vehicle was not diagnosed or repaired. The manufacturer and dealer were not contacted. The failure mileage was 5,641. The VIN was invalid.”

NHTSA complaint #11256119, filed 2019-09, 5,641 miles

“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. …”

NHTSA complaint #11736800, filed 2026-05

“2018 Gmc SIERRA 2500 hd. Consumer writes in regards to acceleration issues. The consumer stated the vehicle displayed warning lights. And began shaking. The vehicle became difficult to accelerate. The dealer informed the consumer that number 4 injector was the cause of the failure. The vehicle was repaired. Shortly after, the glow plug failed and the computer required an update. The consumer requested to reimbursed for the rental vehicle as well as repair costs.”

NHTSA complaint #11451874, filed 2022-02

Related recalls

Related service bulletins

Engine: other model years

YearComplaintsShare of year
202618%
2025414%
20241211%
202339%
202249%
2021815%
20201013%
2019619%
2018823%
2017616%
2016915%
201578%
2014310%
201312%
2012310%
201158%
2010110%
200926%
200846%
200711%
200554%
200496%
200364%
200221%
200186%

Other parts of the 2018 GMC Sierra 2500

Electrical system
7 complaints
Fuel system
6 complaints
Other or unknown
5 complaints
Equipment
4 complaints
Exterior lighting
4 complaints
Tires
3 complaints
Transmission and drivetrain
3 complaints
Visibility (wipers, defrost, mirrors)
2 complaints
Back-over prevention (rear camera)
1 complaints
Seat belts
1 complaints
Steering
1 complaints
Wheels
1 complaints

← All problems reported for the 2018 GMC Sierra 2500

About this data. Data from NHTSA (ODI) complaints, recalls, TSBs and investigations, updated Oct 27, 2026. Complaints are unverified consumer reports and may be duplicated or inaccurate.

To check a specific vehicle for open recalls, use its VIN at nhtsa.gov/recalls. Methodology