2020 Gmc SIERRA DENALI

Problems, Recalls & Reliability Report

Excellent Reliability

Quick Summary

The 2020 Gmc SIERRA DENALI has 10 owner complaints filed with NHTSA — that's 0.1x the segment average of 80. The most common issue is engine problems (60% of all complaints), specifically: i noticed several spots of oil on my driveway, i then inspected the underside of the engine (l5p) and noticed oil dripping from several bolts and lines. my vehicle, a 2020 2500hd denali diesel, has only 2,200 miles on it from normal highway driving..

Total Complaints

Recalls Issued

—/5

Safety Stars

0.1x

vs Segment Avg

Known Problems

ENGINE

6 complaints

60%

• I NOTICED SEVERAL SPOTS OF OIL ON MY DRIVEWAY, I THEN INSPECTED THE UNDERSIDE OF THE ENGINE (L5P) AND NOTICED OIL DRIPPING FROM SEVERAL BOLTS AND LINES. MY VEHICLE, A 2020 2500HD DENALI DIESEL, HAS ONLY 2,200 MILES ON IT FROM NORMAL HIGHWAY DRIVING.
• TWO ISSUES BROKEN VALVE SPRING CAUSED ENGINE TO SHUT DOWN, SECOND SERVICE BRAKE, BRAKE FAILURE LIGHT, SERVICE ESC, SERVICE TRAILER BRAKE MESSAGES CAUSING BRAKE FAILURE
• KNOCKING COMING FROM ENGINE - NOTICEABLE UNNECESSARY NOISE IN WHICH DEALER CAN NOT FIX THE PROBLEM

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

“I NOTICED SEVERAL SPOTS OF OIL ON MY DRIVEWAY, I THEN INSPECTED THE UNDERSIDE OF THE ENGINE (L5P) AND NOTICED OIL DRIPPING FROM SEVERAL BOLTS AND LINES. MY VEHICLE, A 2020 2500HD DENALI DIESEL, HAS ONLY 2,200 MILES ON IT FROM NORMAL HIGHWAY DRIVING.”

— NHTSA complaint filing

BRAKES

2 complaints

20%

• TWO ISSUES BROKEN VALVE SPRING CAUSED ENGINE TO SHUT DOWN, SECOND SERVICE BRAKE, BRAKE FAILURE LIGHT, SERVICE ESC, SERVICE TRAILER BRAKE MESSAGES CAUSING BRAKE FAILURE
• BRAKES SQUEAK. STARTED ABOUT 3000 MILES. I HAVE COMPLAINED TO DEALER SEVERAL TIMES.

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

“TWO ISSUES BROKEN VALVE SPRING CAUSED ENGINE TO SHUT DOWN, SECOND SERVICE BRAKE, BRAKE FAILURE LIGHT, SERVICE ESC, SERVICE TRAILER BRAKE MESSAGES CAUSING BRAKE FAILURE”

— NHTSA complaint filing

ELECTRICAL

1 complaints

10%

• The contact owns a 2020 GMC Sierra Denali. The contact stated while driving 65 MPH at night, the vehicle stalled and the “Shift to Neutral and Restart Vehicle” message was displayed. The contact was unable to restart the vehicle and was unable to visibly see the roadway. The contact was able to park

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

“The contact owns a 2020 GMC Sierra Denali. The contact stated while driving 65 MPH at night, the vehicle stalled and the “Shift to Neutral and Restart Vehicle” message was displayed. The contact was unable to restart the vehicle and was unable to visibly see the roadway. The contact was able to park”

— NHTSA complaint filing

SPEED CONTROL

1 complaints

10%

• The contact owns a 2020 GMC Sierra Denali. The contact stated while driving 75 MPH, the Adaptive Cruise Control feature became inoperable. The contact stated that when the vehicle got too close to another vehicle, the Adaptive Cruise Control feature failed to activate as designed. The vehicle was no

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

“The contact owns a 2020 GMC Sierra Denali. The contact stated while driving 75 MPH, the Adaptive Cruise Control feature became inoperable. The contact stated that when the vehicle got too close to another vehicle, the Adaptive Cruise Control feature failed to activate as designed. The vehicle was no”

— NHTSA complaint filing

Estimated Repair Costs

ENGINE(~50K mi)

$500

BRAKES(~50K mi)

$500

ELECTRICAL(~50K mi)

$500

SPEED CONTROL(~50K mi)

$500

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

🔍 Pre-Purchase Inspection Checklist

Based on 10 owner complaints for this specific year, here's what to check or ask about:

☐
ENGINE: I NOTICED SEVERAL SPOTS OF OIL ON MY DRIVEWAY, I THEN INSPECTED THE UNDERSIDE OF THE ENGINE (L5P) AND NOTICED OIL DRIPPING FROM SEVERAL BOLTS AND LINES. MY VEHICLE, A 2020 2500HD DENALI DIESEL, HAS ONLY 2,200 MILES ON IT FROM NORMAL HIGHWAY DRIVING.
Typically appears around 50K miles. Repair cost ~$500
☐
BRAKES: TWO ISSUES BROKEN VALVE SPRING CAUSED ENGINE TO SHUT DOWN, SECOND SERVICE BRAKE, BRAKE FAILURE LIGHT, SERVICE ESC, SERVICE TRAILER BRAKE MESSAGES CAUSING BRAKE FAILURE
Typically appears around 50K miles. Repair cost ~$500
☐
ELECTRICAL: The contact owns a 2020 GMC Sierra Denali. The contact stated while driving 65 MPH at night, the vehicle stalled and the “Shift to Neutral and Restart Vehicle” message was displayed. The contact was unable to restart the vehicle and was unable to visibly see the roadway. The contact was able to park
Typically appears around 50K miles. Repair cost ~$500
☐
SPEED CONTROL: The contact owns a 2020 GMC Sierra Denali. The contact stated while driving 75 MPH, the Adaptive Cruise Control feature became inoperable. The contact stated that when the vehicle got too close to another vehicle, the Adaptive Cruise Control feature failed to activate as designed. The vehicle was no
Typically appears around 50K miles. Repair cost ~$500
☐
General: Get a pre-purchase inspection from an independent mechanic ($100-$200)