2018 GMC Sierra Denali Engine Problems
- Complaints
- 5about this part
- Share
- 29%of 17 total for the year
- Median mileage
- 107,000miles
- Trend
- Not enough dataFewer than 15 complaints, too few for a reliable trend.
NHTSA recorded 5 complaints about the engine of the 2018 GMC Sierra Denali, 29% of the 17 complaints for this model year. Where a mileage was given, the median is 107,000 miles.
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.
“Driving down the highway about 65mph it made a loud clunk and I took it in to service department and they told me I would have to pay about $400.00 to drain the transmission fluid and replace it. I told them m pick up only has less than 15,000 miles on it I don't think this is fair, the service gu said the don't pay for it and other Gmc denali customers had theirs done and problem was solved and I wasn't the only customer that had the issue and cory from alaska auto body said it was safe to drive”
NHTSA complaint #11385369, filed 2020-12“The contact owns a 2018 GMC Sierra 1500 Denali. The contact stated that while driving at an undisclosed speed, and while the vehicle was parked, the running boards unexpectedly lowered. Additionally, there was oil leaking from the vehicle, and the check engine warning light was illuminated. The vehicle was taken to the dealer, where it was diagnosed with camshaft failure. The contact was informed that the camshaft needed to be replaced. The vehicle was repaired. The manufacturer was made aware of the failure. The approximate failure mileage was 107,000.”
NHTSA complaint #11723657, filed 2026-03, 107,000 miles“1-it needs to apply the brake so hard to make it stop at 100 km/hr and above.. 2-there is a jerk on down '2nd to 1st and up shifting 1st to 2nd gear. 3-front parking sensors sensitivities is not accurate .”
NHTSA complaint #11317267, filed 2020-03“The contact owns a 2018 Gmc Sierra Denali. The contact received a recall notification for NHTSA campaign number: 19v328000 (engine). The contact stated that the manufacturer exceeded a reasonable amount of time for the recall repair. The dealer was not contacted. The manufacturer was notified of the issue and stated that the part was not available. The contact had not experienced a failure. Vin tool confirms parts not available.”
NHTSA complaint #11228903, filed 2019-07Related service bulletins
- 11026017Jun 5, 2025This service bulletin provides information on replacing the intake manifold when the engine is replaced after severe internal engine damage.
- 11024485May 15, 2025The service bulletin advises the tech of a normal transmission shift condition and the delay in throttle response when the throttle plate is opened rapidly and advises the…
- 11020254May 7, 2025This service bulletin provides information to dealership personnel for new vehicles with less than 1,000 miles that may not pass California smog inspection or smog inspection in…
- 11019503Apr 18, 2025This warranty administration bulletin provides policy information on vehicles outside of a California Emissions State who move to and register their vehicle in a California…
- 11017263Mar 25, 2025This bulletin advises the technician to flush the cooling system multiple times if oil has been found in the cooling system and replace the parts that may be contaminated due to…
- 11016942Mar 4, 2025This bulletin advises the technician to flush the cooling system multiple times if oil has been found in the cooling system and replace the parts that may be contaminated due to…
- 11014230Jan 31, 2025This bulletin advises the dealers to maintain the vehicle stock on hand by doing a full inspection on the vehicles before being sold (prepping) to the customer.
- 11014233Jan 30, 2025This service bulletin provides service information to technicians on guidelines to replace Oil Cooler, Oil Cooler Lines and Oil Tank if the engine was replaced where large…
- 11013069Jan 9, 2025This bulletin provides information on identifying Non-GM Engine Calibrations for Gasoline Engines using the Tech 2 or GDS 2.
- 11012907Dec 18, 2024This service bulletin explains how to measure for oil consumption and possible reasons for loss of oil.
Engine: other model years
Other parts of the 2018 GMC Sierra Denali
4 complaintsBody and structure
4 complaintsExterior lighting
3 complaintsSteering
3 complaintsElectronic stability control
2 complaintsTransmission and drivetrain
2 complaintsOther or unknown
1 complaintsSuspension
1 complaintsWheels
1 complaints
← All problems reported for the 2018 GMC Sierra Denali
About this data. Data from NHTSA (ODI) complaints, recalls, TSBs and investigations, updated Oct 30, 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