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What 17 owners told NHTSA about the 2018 GMC Sierra Denali

These are the actual owner complaints behind this car’s reliability verdict, filed with the federal government, unedited. They’re unverified reports, not confirmed defects: read them as leads for your pre-purchase inspection, not a diagnosis.

All (17)Crash / fire / injury (1)Engine (5)Body & structure (4)Brakes (4)Lights (3)Steering (3)Electronic Stability Control (esc) (2)Transmission & drivetrain (2)Suspension (1)Wheels (1)

5 of 17 complaints match · Engine · clear filters

Mar 11, 2026Body & structureEngine

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 ODI 11723657

Dec 28, 2020Transmission & drivetrainEngine

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 ODI 11385369

Apr 7, 2020Engine

TL* THE CONTACT OWNS A 2018 GMC SIERRA DENALI. THE CONTACT RECEIVED NOTIFICATION OF NHTSA CAMPAIGN NUMBER: 19V328000 (ENGINE) HOWEVER, THE PART TO DO THE RECALL REPAIR WAS NOT YET AVAILABLE. THE CONTACT STATED THAT THE MANUFACTURER HAD EXCEEDED A REASONABLE AMOUNT OF TIME FOR THE RECALL REPAIR. SOECHTIN MOTORS GMC LOCATED AT (603 EAST KINGSBURY STREET, SEGUIN, TX 78155, (830)355-2098, WAS CONTACTED AND CONFIRMED THAT THE PART WAS NOT AVAILABLE. THE MANUFACTURER WAS NOT MADE AWARE OF THE ISSUE. PARTS DISTRIBUTION DISCONNECT.

NHTSA ODI 11320407

Mar 10, 2020BrakesEngine

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 ODI 11317267

Jul 2, 2019Engine

TL* 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 ODI 11228903

Working with the data? Download all 17 complaints as CSV · fetched from NHTSA July 20, 2026

How to use these: a complaint is one owner’s report, filed voluntarily and published unverified. Patterns matter more than any single story. If several owners describe the same failure at similar mileage, put that system at the top of your pre-purchase inspection list. Back to the full 2018 GMC Sierra Denali verdict →