Is the 2018 Gmc SIERRA DENALI reliable?

The 2018 Gmc SIERRA DENALI has 26 complaints filed with NHTSA (1.4x the segment average). Our reliability verdict: average. Most common issue: ENGINE problems.

What are common problems with the 2018 Gmc SIERRA DENALI?

Top problems: ENGINE (5 complaints, avg repair $500); BRAKES (4 complaints, avg repair $500); BODY/STRUCTURE (4 complaints, avg repair $500). Issues typically appear around 50K miles.

Are there any recalls on the 2018 Gmc SIERRA DENALI?

No recalls have been issued for the 2018 Gmc SIERRA DENALI.

How much does it cost to insure a 2018 Gmc SIERRA DENALI?

Estimated US average full-coverage insurance for the 2018 Gmc SIERRA DENALI is approximately $1,607/year (sedan-midsize class). Actual quotes vary heavily by state, driver age, driving record, and credit — see the interactive insurance estimator on this page for state-specific pricing.

2018 Gmc SIERRA DENALI

Problems, Recalls & Reliability Report

Average

Quick Summary

The 2018 Gmc SIERRA DENALI has 26 owner complaints filed with NHTSA — that's 1.4x the segment average of 19. The most common issue is engine problems (19% of all complaints), specifically: 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.

3 injuries

Total Complaints

Recalls Issued

—/5

Safety Stars

1.4x

vs Segment Avg

Known Problems(top 5 of 8)

ENGINE

5 complaints

19%

• 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
• 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 .
• 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. SOEC

Typical onset: 50K miles Est. repair: $500

“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”

— NHTSA complaint filing

When Problems Appear on the 2018 Gmc SIERRA DENALI

Based on 19 owner complaints that included an odometer reading. Median mileage at time of complaint: 26K miles. Most complaints cluster in the 0-30K miles range.

Overall complaint distribution by mileage

0-30K

30-60K

60-100K

100-150K

150-200K

200K+

Mileage figures are self-reported by owners in NHTSA complaint filings. Peak bucket = the mileage range with the most complaints for that component; it reflects when owners noticed and reported problems, not necessarily when the fault first occurred.

Estimated Insurance Cost for 2018 Gmc SIERRA DENALI

Estimate only, not a quote. Modeled from NAIC + HLDI averages for a hypothetical 35-year-old driver with clean record + full coverage. Your actual quote depends heavily on your age, driving history, credit, ZIP code, and insurer.

Your state (affects local premium average)

Full coverage / year

$1,607

Full coverage / month

$134

Liability only / year

$611

vs US avg

-4%

How this estimate is calculated

US base full-coverage premium$1674

× state (US)1.00x

× vehicle class (sedan-midsize)0.96x

× theft risk1.00x

× safety rating1.00x

× vehicle age1.00x

= Full coverage estimate$1607

Coverage assumed: 100/300/100 liability + comprehensive/collision, $500 deductibles. Data sources: NAIC 2024 + HLDI loss studies.

Maintenance & Warranty

Recommended Gmc SIERRA DENALI Service Intervals

Oil change

8K mi / 12 mo

Tire rotation

8K mi

Brake fluid

36 months

Transmission fluid

45K mi

Engine coolant

150K mi

Spark plugs

100K mi

Cabin air filter

23K mi

Engine air filter

45K mi

Differential (AWD/4WD)

45K mi

Uses GM Oil Life System. Full-size trucks may have shorter differential and transfer case intervals if used for towing.

"Severe service" conditions (heavy towing, extreme temps, city stop-and-go) typically halve these intervals. Always consult your vehicle's owner's manual for the authoritative schedule.

Gmc New-Vehicle Warranty Coverage

Bumper-to-bumper (basic)

3 yr / 36K mi

Powertrain

5 yr / 60K mi

Hybrid/EV battery

8 yr / 100K mi

Corrosion (rust perforation)

6 yr / 100K mi

Roadside assistance

5 yr / 60K mi

These are the terms for a new Gmc. If you're buying a used 2018 SIERRA DENALI, remaining coverage is usually pro-rated from the vehicle's original in-service date. Not all coverage transfers between owners — check with a Gmc dealer for VIN-specific remaining warranty.

Estimated Repair Costs

ENGINE(~50K mi)

$500

BRAKES(~50K mi)

$500

BODY/STRUCTURE(~50K mi)

$500

LIGHTING(~50K mi)

$500

STEERING(~50K mi)

$500

Estimates based on average reported repair costs. Actual costs vary by location, shop, and severity.

🔍 Pre-Purchase Inspection Checklist

Based on 26 owner complaints for this specific year, here's what to check or ask about:

☐
ENGINE: 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
Typically appears around 50K miles. Repair cost ~$500
☐
BRAKES: 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 .
Typically appears around 50K miles. Repair cost ~$500
☐
BODY/STRUCTURE: THE REAR END MAKES NOISE WHEN TURNING AND SOMETIMES STOPING. WHEN WEIGHT IS PLACE ON BED THE REAR END MAKE NOISES. SOMETHING IS WRONG IN THE REAR END OF THIS TRUCK. WHEN TRUCK IS MOVING AND TURNING YOU CAN HERE THE NOISE.
Typically appears around 50K miles. Repair cost ~$500
☐
LIGHTING: TL* THE CONTACT OWNS A 2018 GMC SIERRA DENALI. WHILE DRIVING VARIOUS SPEEDS, THE HEADLIGHTS MOVED WHEN DRIVING OVER A BUMP IN THE ROAD. THE VEHICLE WAS TAKEN TO WHITAKER BUICK GMC (131 19TH ST SW, FOREST LAKE, MN 55025, (651) 464-5612) AND MCCARTHY AUTO WORLD (3350 129TH AVE NW, COON RAPIDS, MN 5544
Typically appears around 50K miles. Repair cost ~$500
☐
General: Get a pre-purchase inspection from an independent mechanic ($100-$200)