2021 Mercedes Benz Glc Class Recalls, Issues & Maintenance

The 2021 Mercedes Benz Glc Class has no open NHTSA recalls. Owners report 7 recurring issue clusters, led by “Cylinder head failure with power loss and misfires.” Mercedes-Benz alternates two service events: Service A (oil, filter, inspection) at roughly 10,000 miles or 1 year, then Service B (Service A plus brake fluid, cabin filter, and deeper checks) at roughly 20,000 miles or 2 years — the ASSYST Plus counter in the cluster tells you which is due. Oil must carry the MB-Approval number your engine specifies (commonly 229.5, or 229.71 for newer 0W-20 engines); 'meets or exceeds' marketing language is not an approval. Electric EQB and EQS models keep the A/B rhythm for inspections, brake fluid, and cabin filters — just without oil.

No open recalls on file. NHTSA lists no unrepaired safety recalls for this year, make and model. A recall can be issued at any time, and a specific car can still have one open — check yours by VIN at nhtsa.gov/recalls.

Known issues for this vehicle

What drivers and federal regulators have officially reported about the 2021 Mercedes Benz Glc Class.

Reported to NHTSA

Cylinder head failure with power loss and misfires

ENGINE

22 NHTSA complaints · 2021-03 → 2026-06

The dealer confirmed a catastrophic cylinder head engine failure. The vehicle had only 39,000 miles. After some investigating, there have been numerous complaints from vehicle owners with the same issue on the M264 engine (which is what my vehicle has)
Owner report, NHTSA ODI #11707845
While driving, my 2021 Mercedes-Benz GLC 300 began experiencing repeated engine misfires and rough running, accompanied by a persistent check engine light. These symptoms began shortly after I purchased the vehicle and progressively worsened over time. The vehicle exhibited…
Owner report, NHTSA ODI #11709709
While driving my vehicle on March 3, 2025 the check engine light came on. Additionally my vehicle began to shake. I was scheduled for a service appointment on March 5, 2025 and told the service department the check engine light need to be…
Owner report, NHTSA ODI #11648292
The contact stated that while driving at various speeds, the vehicle would lose power and fail to accelerate upon the depression of the accelerator pedal. The check engine light would appear on the instrument panel. Despite the failure, the vehicle would resume normal operation…
Owner report, NHTSA ODI #11607115

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Headlight condensation and failure outside recall scope

EXTERIOR LIGHTING

11 NHTSA complaints · 2024-01 → 2026-08

Moisture began collecting inside the left headlight assembly, even though the housing should be sealed. Over time, the condensation increased and the front left turn signal failed. The vehicle displayed warning messages for the turn signal, low beams, Blind Spot Assist, Traffic…
Owner report, NHTSA ODI #11754832
Have been getting condensate inside vehicle headlights inwhich have cause the headlight to completely not work anymore.. There is no damage to headlight which means to be cause due to a problem with the seal. Checked with local and also statewide Mercedes advisors which was told…
Owner report, NHTSA ODI #11674539
Vehicle left/front headlight has water condensation and entire headlight doesn't work. Its pretty much not drivable. I brought the vehicle to a manufacturer dealership and they claim that the failure of the headlight is due to physical impact to the exterior of head light
Owner report, NHTSA ODI #11567054

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Sudden engine power loss and limp mode while driving

FUEL/PROPULSION SYSTEM, ENGINE, POWER TRAIN

8 NHTSA complaints · 2021-04 → 2025-11

In all instances, we were travelling at a normal rate of in-city traffic (30-45 mph) and all of sudden the vehicle will not accelerate above 25 mph regardless of the position of the throttle. My dealer, Mercedes Benz of Tampa, advises that the problem can only be corrected…
Owner report, NHTSA ODI #11559715
There is a hesitation in or "shuddering" that causes the car to go into limp mode while in operation. I was in traffic and the car just powered down and would not get up to and or maintain speed. I contacted the local dealership and was told that there are other models and or…
Owner report, NHTSA ODI #11698959
the check engine light came on & I had a loss of power to where it slowed down & would not go any faster than about 30/35 miles an hour going on a straight road way & no faster than about 10 miles an hour going uphill. The engine sounded funny as well. It had to be towed to the…
Owner report, NHTSA ODI #11486730

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Oil pressure solenoid wiring fault code P06DA

ELECTRICAL SYSTEM, ENGINE

2 NHTSA complaints · 2026-02 → 2026-05

Fault code P06DA00 Engine Oil Pressure Control Circuit/Open. The Yellow Check Engine Light came on and the engine does not run properly and causes engine damage. We had to drive it slowly, under 45 mph, to the nearest dealership. This is a safety issue. To replace the oil pump…
Owner report, NHTSA ODI #11718651
Getting P06DA trouble code meaning that there is something wrong with the oil pressure solenoid in the oil sump. this is a known issue where the wiring of the solenoid get frayed. cost of repair for the (cheap part) is $7,500 because of 18 hour labor involved
Owner report, NHTSA ODI #11735862

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Panoramic sunroof glass spontaneous shattering

STRUCTURE:BODY, VISIBILITY/WIPER

3 NHTSA complaints · 2022-05 → 2023-05

Sunroof glass panel exploded outward. Fabric retractable interior sunroof liner did contain all of the fragmented safety glass. No prior impact on or to the sunroof. If the interior fabric sunroof liner had been retracted, the interior of the vehicle would have been showered…
Owner report, NHTSA ODI #11466660
My sunroof exploded while I was driving on the highway. There were no other cars around me and no overpasses. There is no explanation for the sunroof breaking. I thought someone shot out my window. It was the scariest experience I have ever had driving
Owner report, NHTSA ODI #11502302

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Fuel system failure causing stall or loss of propulsion

FUEL/PROPULSION SYSTEM

4 NHTSA complaints · 2021-06 → 2024-12

Fuel line malfunctioned, car stopped , gasoline was pouring out from under the hood. I was "lucky" that it did not catch fire, fire department showed up, closed the street, car was towed, dealership " replaced high-pressure line of fuel system high pressure pump"
Owner report, NHTSA ODI #11421117
The contact stated that while driving at low speeds, the vehicle lost motive power struggling to produce enough power to propel itself on a slight incline. The check engine warning light was illuminated. The vehicle was taken to an independent mechanic, who diagnosed a failure…
Owner report, NHTSA ODI #11628817

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Blind Spot Assist and Active Brake Assist inoperative

FORWARD COLLISION AVOIDANCE: AUTOMATIC EMERGENCY BRAKING, LANE DEPARTURE: BLIND SPOT DETECTION, AIR BAGS

2 NHTSA complaints · 2022-12 → 2026-03

Vehicle will flash warnings on dash the the blind spot assist in inoperative and the front passenger air bag malfunction. The active brake assist is also malfunctioning as the two white cars colliding is on. The dealership as tried to fix this issue 5 times
Owner report, NHTSA ODI #11499353
This 2021 Mercedes-Benz GLC 63 AMG has experienced repeated and escalating warranty defects involving engine performance, loss of acceleration, air suspension failure, and now inoperative advanced safety systems including blind spot and active brake assist
Owner report, NHTSA ODI #11725180

Read all complaints on NHTSA →

Source: NHTSA Office of Defects Investigation (ODI). Complaint data refreshed Sep 13, 2026. Investigation data refreshed Sep 13, 2026.

We display NHTSA's record with attribution; we don't editorialize on what these complaints mean for any specific vehicle.

Essential maintenance

Critical for safety and preventing major damage

Service A — Oil & Filter + Inspection

Every 10,000 mi

Every 10,000 miles or 12 months: oil and filter with MB-Approved oil, fluid top-offs, tire check, and inspection. AMG models driven hard: many owners service at 5,000-7,500 miles.

Estimated cost — typical U.S. ranges

Dealer

~$120–$160

Shop

~$85–$115

DIY

~$25–$55

Full synthetic costs more than conventional. 5-quart 0W-20 + filter is the typical bill.

Service B — Major Inspection

Every 20,000 mi

Every 20,000 miles or 2 years, alternating with Service A: everything in A plus brake-fluid replacement, cabin filter, and a deeper multi-point inspection of brakes, suspension, and driveline.

Estimated cost — typical U.S. ranges

Dealer

~$85

Shop

~$60

DIY

Free

Most shops do this free with any paid service. A flashlight and 10 minutes covers the basics yourself.

Tire Rotation

Every 10,000 mi

Rotate at every Service A where the tire sizes allow. Many AMG and 4MATIC+ models run staggered widths that can't rotate front-to-rear — check your spec before paying for a rotation.

Estimated cost — typical U.S. ranges

Dealer

~$85

Shop

~$60

DIY

Free

Often free at the shop where you bought the tires — worth asking before paying.

Brake Inspection

Every 10,000 mi

Checked at every A/B service via electronic pad-wear sensors. Replace sensors with pads. Heavy EQS models wear pads slowly (regen braking) but rotors can corrode from disuse — an inspection catches that.

Estimated cost — typical U.S. ranges

Dealer

~$85

Shop

~$60

DIY

Free

Most shops do this free as a courtesy with any service. Don't pay separately if you can avoid it.

Brake Fluid

Every 20,000 mi

Replaced every 2 years as part of Service B — Mercedes schedules it on time, not miles, because DOT 4 fluid absorbs moisture regardless of driving.

Estimated cost — typical U.S. ranges

Dealer

~$180–$200

Shop

~$125–$140

DIY

~$10–$25

DOT 3 or 4 — match the cap. Vacuum bleeders make this a one-person DIY.

Important maintenance

Keeps your vehicle running smoothly and efficiently

Automatic Transmission Fluid (7G / 9G-Tronic)

Every 70,000 mi

Mercedes specifies fluid and filter service around 70,000 miles on most 7G- and 9G-Tronic gearboxes — check your year's sheet. Use only the MB-spec fluid for your transmission code; independent specialists often service at 60,000 on hard-driven cars.

Estimated cost — typical U.S. ranges

Dealer

~$330–$500

Shop

~$235–$355

DIY

~$60–$180

Some sealed transmissions have no dipstick — fill is precise and best left to a shop. Many drivers can still DIY drain-and-fill.

Spark Plugs

Every 60,000 mi

Most modern MB gas engines: plugs around 60,000 miles — AMG engines often sooner. Check your engine's sheet; twin-turbo V8 plug jobs are labor-heavy, so pair with other scheduled work.

Estimated cost — typical U.S. ranges

Dealer

~$285–$390

Shop

~$200–$275

DIY

~$25–$100

Iridium plugs cost more but last 100k+ miles. V6/V8 access varies wildly — some are tough.

Engine Air Filter

Every 40,000 mi

Replace around every 40,000 miles (twin-filter setups on V6/V8 engines double the parts bill). Inspected at every Service B.

Estimated cost — typical U.S. ranges

Dealer

~$60–$95

Shop

~$45–$70

DIY

~$15–$40

5-minute job on most cars; the airbox lid usually has clips, no tools needed.

Recommended maintenance

Extends the life of your vehicle and improves comfort

Combination / Dust Filter

Every 20,000 mi

Replaced with every Service B. Models with the ENERGIZING air package use a higher-grade filter — priced accordingly.

Estimated cost — typical U.S. ranges

Dealer

~$60–$95

Shop

~$45–$70

DIY

~$15–$40

Usually behind the glovebox. Shops charge labor for a 10-minute job — easy DIY win.

Engine Coolant

On condition / lifetime

MB-spec coolant is long-life (typically ~10 years / 150,000 miles on the sheet). Refresh only with MB 325/326-spec coolant — the wrong chemistry attacks aluminum and head gaskets.

Estimated cost — typical U.S. ranges

Dealer

~$285–$330

Shop

~$200–$235

DIY

~$25–$60

Use the manufacturer-specified coolant — wrong color/chemistry can damage the cooling system.

12V & Auxiliary Battery

Every 25,000 mi

Test annually after year 3. Most modern Mercedes carry a second auxiliary battery; a weak one triggers cascading warning messages long before a no-start. EQ models also depend on the 12V system to boot.

Estimated cost — typical U.S. ranges

Dealer

~$225–$390

Shop

~$160–$280

DIY

~$130–$250

Most auto-parts stores test and install batteries free with purchase. Skip the dealer markup.

Fatal crash history & reported problems

Occupant deaths in fatal crashes (FARS)

5 crashes 2010–2024

FARS counts every occupant death in a fatal crash, whatever the cause — it does not mean the vehicle was at fault or defective. Counts are not adjusted for how many of each vehicle are on the road. How to read this number

Owner-reported problem signals

Separate from the federal fatality data above: complaints owners filed with NHTSA about this year and model. These are reports of problems, unverified, and are counted here only as signals.

0

complaints mentioning a crash

0

complaints mentioning a fire

Reviewed known issues for this vehicle

Typical U.S. ranges. Actual quotes vary by shop, parts choice, and vehicle condition.

How we estimate: Dealer = OEM parts × 1.4 + labor × $165/hr. Shop = parts + labor × $115/hr. DIY = parts only.

This maintenance schedule for the 2021 Mercedes Benz Glc Class reflects Mercedes-Benz's published service intervals and the ASSYST Plus (Service A / Service B) system. Your actual service needs may vary based on driving conditions, climate, and vehicle usage. Always consult your owner's manual for model-specific recommendations.