2018 Mercedes-Benz GLC 300 problems & reliability
87 owner complaints filed with NHTSA for the 2018 Mercedes-Benz GLC 300, alongside 12 safety recall campaigns. Last verified Sep 21, 2026. Complaints are unverified reports submitted by owners to the federal Office of Defects Investigation.
Each complaint is counted once (by NHTSA case number), even when it names several components.
2 complaints report injuries (2 injured).
Most reported problems
| Component | Complaints | Share |
|---|---|---|
| Engine → | 28 | 32% |
| Unknown / Other | 20 | 23% |
| Electrical System → | 13 | 15% |
| Structure | 9 | 10% |
| Power Train | 8 | 9% |
| Seat Belts | 8 | 9% |
| Fuel/propulsion System | 7 | 8% |
| Air Bags | 6 | 7% |
| Service Brakes | 5 | 6% |
| Forward Collision Avoidance | 3 | 3% |
Component groups as classified by NHTSA. A complaint can name more than one component, so shares may sum to more than 100%.
All 21 reported components →Common symptoms owners describe
Keyword analysis of complaint narratives; one complaint can describe several symptoms.
Mileage when problems occurred
Among the 27 complaints that included a usable odometer reading, the median reported incident mileage was 16,000 miles (middle 50% between 6,452 and 49,500 miles).
Complaints by incident year
What owners report
“Error code P052E71 on a 2018 Mercedes-Benz GLC 300 4MATIC means the Positive Crankcase Ventilation (PCV) Regulator Valve Performance has a malfunction, specifically that the partial-load ventilation valve actuator is blocked. By research, i found that this is a very common problem on those engines, and no recalls from…”
Engine · filed Jul 30, 2026
“Component Failure: The vehicle is equipped with the M274 2.0L turbocharged engine, which suffered a major internal mechanical defect. An authorized Mercedes-Benz dealership diagnosed the vehicle at 79,504 miles with a malfunction in the crankcase ventilation system alongside severe internal defects, quoting a total…”
Power Train · filed Jun 3, 2026
“Safety Issue: Infotainment display screen produces scrambled pixels during Apple CarPlay navigation while driving. Description: When Apple CarPlay is connected and navigation is in use, the vehicle's infotainment display screen suddenly produces scrambled pixels, rendering the map and display unreadable. This…”
Unknown / Other · filed Apr 21, 2026
Verbatim excerpts from complaints filed with NHTSA. Reports are not independently verified.
Federal defect investigations
- Desiccated Air Bag Inflator Rupture
Engineering Analysis EA21002 · opened Sep 17, 2021 · open
Technical service bulletins
205 manufacturer communications (TSBs, service campaigns, warranty extensions) are on file with NHTSA for the 2018 Mercedes-Benz GLC 300. The 10 most recent:
Complaint During part of the steering movement, it feels heavier or more difficult to steer in the same spot every time. OR Rattling, humming, dry sliding/gravel noise from the electric steering system when steering…
LI46.35-P-067339 · Service Bulletin/Repair Instructions · issued Aug 28, 2026
Complaint Tailgate opens unintentionally. Cause Accidental or unnoticed activation of the button to open the tailgate on the vehicle key. EXAMPLE: when stored in trouser pocket, handbag etc. Remedy As of the 6th…
LI72.20-P-075746 · Service Bulletin/Repair Instructions · issued Aug 24, 2026
Dear Mercedes-Benz Owner: In our continuing efforts to ensure the proper performance of Mercedes-Benz products and to enhance the satisfaction of our customers, Mercedes-Benz USA is extending the warranty coverage for…
CL - Tank Leak Detection · Warranty Program/Extension · issued Aug 15, 2026
Complaint 1. General Diagnostic Tips 2. One or More PARK Sensor Activations 3. Red Ring Around Vehicle 4. "Active Parking and Parking Assist Inoperative" on Instrument Cluster 5. Cameras 6. Other Park Topics. Cause…
LI54.65-P-080132 · Service Bulletin/Repair Instructions · issued Aug 12, 2026
Complaint A popup is seen on the HU with the message "data connection temporarily not available". Potentially affected functionalities in NTG4.5, NTG5 1.Weather 2.Local Search 3.IP Radio 4.Send2Car 5.Speech Detection…
LI82.85-P-079087 · Service Bulletin/Repair Instructions · issued Aug 6, 2026
Complaint Clanking noise from the area of the speakers in the doors. Cause Under analysis. Remedy To narrow down the cause, first of all remove the door trim. • If the noise continues to occur even with the door trim…
LI82.62-P-078631 · Service Bulletin/Repair Instructions · issued Aug 6, 2026
Complaint This document is intended as a pre-case diagnostic reference for transmission related concerns. It will also ensure that if a case is necessary, all supporting documentation is available. This should not be…
LI27.00-P-075630 · Service Bulletin/Repair Instructions · issued Aug 5, 2026
Complaint Mercedes-Benz USA is currently experiencing limited availability of transmission fluid specification ATF 236.17 due to a global supply constraint. 236.17 ATF 1L and 5L (PNs: A002989060312 and A002989060313)…
LI27.00-P-080840 · Service Bulletin/Repair Instructions · issued Aug 4, 2026
This NCU replaces the prior NCU issued on May 15, 2025, and contains additional MY 2023 and MY 2024 vehicles which are highlighted below. In our continuing efforts to ensure the proper performance of Mercedes-Benz…
EW - DMTL · Warranty Program/Extension · issued Jul 31, 2026
Single throttle lift-off clunking noise from the side shaft when moving off (audible at the outboard end). The noise is heard once in each instance when changing direction of travel. Note: Sound file in attachment Cause…
LI35.30-P-058566 · Service Bulletin/Repair Instructions · issued Jul 14, 2026
TSBs are repair guidance manufacturers send to dealers — they are not recalls and repairs are not automatically free. Full documents are available on NHTSA’s site.
Safety recalls
The 2018 Mercedes-Benz GLC 300 has 12 NHTSA recall campaigns — recall repairs are free at franchised dealers regardless of the vehicle’s age.
Check whether your specific vehicle is affected
Recall campaigns often cover only certain VIN ranges. Enter your VIN on the official NHTSA site to confirm whether your vehicle is included and whether the repair is still open.
Check VIN on NHTSA →Buying a used 2018 Mercedes-Benz GLC 300?
- · Decode the seller’s VIN with our free VIN decoder to confirm the exact year, engine and trim.
- · Check for unrepaired recalls by VIN on NHTSA’s official lookup — recall repairs are free.
- · Among complaints with usable mileage, the median reported incident mileage was 16,000 miles. This does not predict when a particular vehicle will develop a problem.