2018 Mercedes-Benz GLS 450

Problems, Recalls & Reliability Report

Excellent Reliability

Quick Summary

The 2018 Mercedes-Benz GLS 450 has 20 owner complaints filed with NHTSA — that's 0.3x the segment average of 80. The most common issue is suspension problems (15% of all complaints), specifically: i took the car to the service 3 times in 4 months. there are many problems with the car. the first problem was that the left rear shock was leaking which made a squeaking noise when driving. there was also an odor problem with the car that was coming from the ventilations. these two problems were fi. ⚠️ 4 fire reports filed.

4 fire reports 1 crash report

Total Complaints

Recalls Issued

—/5

Safety Stars

0.3x

vs Segment Avg

Known Problems

SUSPENSION

3 complaints

15%

• I TOOK THE CAR TO THE SERVICE 3 TIMES IN 4 MONTHS. THERE ARE MANY PROBLEMS WITH THE CAR. THE FIRST PROBLEM WAS THAT THE LEFT REAR SHOCK WAS LEAKING WHICH MADE A SQUEAKING NOISE WHEN DRIVING. THERE WAS ALSO AN ODOR PROBLEM WITH THE CAR THAT WAS COMING FROM THE VENTILATIONS. THESE TWO PROBLEMS WERE FI
• This 2018 gls 450 has issues with suspension system. Bought this car in 2023 and using since Jna 2023 and suspension system failed like 3 -4 times. Mechanic changed the air compressor , valves and others and still the car has same issue. It used to lift the car to adequate height but the compressor
• When attempting to rise/lower the automatic suspension, the compressor cooling notification pops up, followed by a malfunction. After this occurs, the vehicle is incredibly bumpy, to the point of it being unsafe to drive. The vehicle has been repaired twice already by the dealership under extended w

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

“I TOOK THE CAR TO THE SERVICE 3 TIMES IN 4 MONTHS. THERE ARE MANY PROBLEMS WITH THE CAR. THE FIRST PROBLEM WAS THAT THE LEFT REAR SHOCK WAS LEAKING WHICH MADE A SQUEAKING NOISE WHEN DRIVING. THERE WAS ALSO AN ODOR PROBLEM WITH THE CAR THAT WAS COMING FROM THE VENTILATIONS. THESE TWO PROBLEMS WERE FI”

— NHTSA complaint filing

BRAKES

3 complaints

15%

• I WAS ALREADY 90% IN PARKING LINE WHICH IS HANDICAP'S. ABOUT TO STOP RIGHT FRONT OF HANDICAP SIGN, SUDDENLY VEHICLE START MOVING FORWARD WHILE MY FOOT WAS IN BRAKE SO I PUSH LITTLE HARD TO COMPLETE STOP BUT VEHICLE SUDDENLY ACCELERATE FORWARD SMASHING INTO THE BUILDING GLASS ENTRY WALL AND DOOR. I A
• Brake brakes are terrible. They have other years that they’ve acknowledge that the break are spongy and at times does not break the GLS has that defect. Also smell of gas fumes inside the vehicle. Please direct me the right way and help me with this issue. The brake issue almost have caused me two m
• January 2023 - Airbag suspension failed. Replaced by Mercedes dealership. December 2024 - Airbag suspension failed. Replaced by Mercedes dealership. April 2024: First brake failure. The brakes stopped while driving. Repaired. April 2025: Second brake failure. Brakes failed again. Repaired. The mec

Typical onset: 50K miles Est. repair: $500🔥 1 fire reports💥 1 crashes

“I WAS ALREADY 90% IN PARKING LINE WHICH IS HANDICAP'S. ABOUT TO STOP RIGHT FRONT OF HANDICAP SIGN, SUDDENLY VEHICLE START MOVING FORWARD WHILE MY FOOT WAS IN BRAKE SO I PUSH LITTLE HARD TO COMPLETE STOP BUT VEHICLE SUDDENLY ACCELERATE FORWARD SMASHING INTO THE BUILDING GLASS ENTRY WALL AND DOOR. I A”

— NHTSA complaint filing

ELECTRICAL

2 complaints

10%

• TL* THE CONTACT OWNS A 2018 MERCEDES-BENZ GLS450. WHILE DRIVING 70 MPH, THE VEHICLE LOST POWER AND ALL THE WARNING INDICATORS ON THE INSTRUMENT PANEL ILLUMINATED. ALSO, WHEN THE BRAKE PEDAL WAS DEPRESSED, THE VEHICLE FAILED TO STOP. THE CONTACT STATED THAT THE VEHICLE FINALLY STOPPED UPON REACHING A
• I TOOK THE CAR TO THE SERVICE 3 TIMES IN 4 MONTHS. THERE ARE MANY PROBLEMS WITH THE CAR. THE FIRST PROBLEM WAS THAT THE LEFT REAR SHOCK WAS LEAKING WHICH MADE A SQUEAKING NOISE WHEN DRIVING. THERE WAS ALSO AN ODOR PROBLEM WITH THE CAR THAT WAS COMING FROM THE VENTILATIONS. THESE TWO PROBLEMS WERE FI

Typical onset: 50K miles Est. repair: $500🔥 1 fire reports

“TL* THE CONTACT OWNS A 2018 MERCEDES-BENZ GLS450. WHILE DRIVING 70 MPH, THE VEHICLE LOST POWER AND ALL THE WARNING INDICATORS ON THE INSTRUMENT PANEL ILLUMINATED. ALSO, WHEN THE BRAKE PEDAL WAS DEPRESSED, THE VEHICLE FAILED TO STOP. THE CONTACT STATED THAT THE VEHICLE FINALLY STOPPED UPON REACHING A”

— NHTSA complaint filing

BODY/STRUCTURE

2 complaints

10%

• PART OF MY PANORAMIC SUNROOF SPONTANEOUSLY SHATTERED WHILE SITTING AT A STOPLIGHT. THERE WERE NO CARS OR TREES AROUND AT THE TIME. NOTHING TOUCHED THE CAR WHEN IT HAPPENED.
• While driving our 2018 Mercedes GLS 450 down Highway 80 just outside Sacramento, CA, the stationary glass panel of our panoramic sunroof spontaneously explpoded. There was no impact by any outside force, it just shattered with the sound similar to a gunshot. Fortunately I did not lose control of the

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

“PART OF MY PANORAMIC SUNROOF SPONTANEOUSLY SHATTERED WHILE SITTING AT A STOPLIGHT. THERE WERE NO CARS OR TREES AROUND AT THE TIME. NOTHING TOUCHED THE CAR WHEN IT HAPPENED.”

— NHTSA complaint filing

ENGINE

2 complaints

10%

• The contact owned a 2018 Mercedes Benz GLS450. The contact stated that after turning the ignition switch off, the driver suddenly discovered flames were coming from the engine compartment. The fire department was called to the scene and extinguished the flames. During the incident, the vehicle was d
• January 2023 - Airbag suspension failed. Replaced by Mercedes dealership. December 2024 - Airbag suspension failed. Replaced by Mercedes dealership. April 2024: First brake failure. The brakes stopped while driving. Repaired. April 2025: Second brake failure. Brakes failed again. Repaired. The mec

Typical onset: 50K miles Est. repair: $500🔥 2 fire reports

“The contact owned a 2018 Mercedes Benz GLS450. The contact stated that after turning the ignition switch off, the driver suddenly discovered flames were coming from the engine compartment. The fire department was called to the scene and extinguished the flames. During the incident, the vehicle was d”

— NHTSA complaint filing

Estimated Repair Costs

SUSPENSION(~50K mi)

$500

BRAKES(~50K mi)

$500

ELECTRICAL(~50K mi)

$500

BODY/STRUCTURE(~50K mi)

$500

ENGINE(~50K mi)

$500

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

🔍 Pre-Purchase Inspection Checklist

Based on 20 owner complaints for this specific year, here's what to check or ask about:

☐
SUSPENSION: I TOOK THE CAR TO THE SERVICE 3 TIMES IN 4 MONTHS. THERE ARE MANY PROBLEMS WITH THE CAR. THE FIRST PROBLEM WAS THAT THE LEFT REAR SHOCK WAS LEAKING WHICH MADE A SQUEAKING NOISE WHEN DRIVING. THERE WAS ALSO AN ODOR PROBLEM WITH THE CAR THAT WAS COMING FROM THE VENTILATIONS. THESE TWO PROBLEMS WERE FI
Typically appears around 50K miles. Repair cost ~$500
☐
BRAKES: I WAS ALREADY 90% IN PARKING LINE WHICH IS HANDICAP'S. ABOUT TO STOP RIGHT FRONT OF HANDICAP SIGN, SUDDENLY VEHICLE START MOVING FORWARD WHILE MY FOOT WAS IN BRAKE SO I PUSH LITTLE HARD TO COMPLETE STOP BUT VEHICLE SUDDENLY ACCELERATE FORWARD SMASHING INTO THE BUILDING GLASS ENTRY WALL AND DOOR. I A
Typically appears around 50K miles. Repair cost ~$500
☐
ELECTRICAL: TL* THE CONTACT OWNS A 2018 MERCEDES-BENZ GLS450. WHILE DRIVING 70 MPH, THE VEHICLE LOST POWER AND ALL THE WARNING INDICATORS ON THE INSTRUMENT PANEL ILLUMINATED. ALSO, WHEN THE BRAKE PEDAL WAS DEPRESSED, THE VEHICLE FAILED TO STOP. THE CONTACT STATED THAT THE VEHICLE FINALLY STOPPED UPON REACHING A
Typically appears around 50K miles. Repair cost ~$500
☐
BODY/STRUCTURE: PART OF MY PANORAMIC SUNROOF SPONTANEOUSLY SHATTERED WHILE SITTING AT A STOPLIGHT. THERE WERE NO CARS OR TREES AROUND AT THE TIME. NOTHING TOUCHED THE CAR WHEN IT HAPPENED.
Typically appears around 50K miles. Repair cost ~$500
☐
General: Get a pre-purchase inspection from an independent mechanic ($100-$200)