There are 7 owner-reported engine complaints for the 2019 Mercedes-Benz GLC-Classin NHTSA's database. These are unverified consumer reports and may not reflect confirmed defects.
Faulty Positive Crankcase Ventilation Valve. Seems a very common failure which causes poor emissions and potentially further engine damage.
The contact owns a 2019 Mercedes-Benz GLC350. The contact stated while driving 62 MPH, several unknown warning lights illuminated, and the vehicle started to lose motive power. The contact stated that the temperature gauge warning light was illuminated and a message to “Stop Vehicle Immediately” was displayed. The contact attempted to merge to the side of the road; however, the vehicle started losing motive power. The vehicle was towed to a dealer where it was diagnosed with a warped head gasket. The local dealer was contacted; however, the vehicle was not repaired. The manufacturer was made aware of the failure. The failure mileage was approximately 63,000.
P052E71 Engine Separator and actuator malfunctioning. Was told this fails several times on Mercedes vehicles. I will not pass emissions with this issue. Over $2K to repair and engine light along with code appears. I have videos of the engine light coming off and on. Car has been inspected by Firestone and Mercedes Service Center.
P052E system replacement needed at 52880 miles
Cracked piston due to a faulty wrist pin installed in the MBZ M274 engine. Yes, available for inspection. Car began shaking and I would not have been able to control it if I had been driving at a higher speed. Yes, the problem is well known amongst MBZ and the service manager admitted to this engine having resulting cracked pistons. The "check engine" light did not come on until the day after the severe shaking of the vehicle. This should have been a safety recall years ago.
The Crankcase ventilation valve has a malfunction. The actuator is blocked. Code #052E71. The manufacturer has inspected the vehicle and confirmed the issue. The same issue has happened repeatedly to numerous Mercedes owners. The car is not safe to drive with this issue because it could cause engine problems.
While driving on the interstate (65mph) in traffic, there was a sudden loss of power causing deceleration and the inability to maintain speed. A collision was barely avoided both from being rear-ended and from trying to safely move to the shoulder while other traffic passed. A certified mechanic later determined the piston in cylinder 2 broke, the spark plug broke and the piston rings pulled to the top. The mechanic also said, "Replacement of engine required." The vehicle has 52,839 miles (2,839 miles above the 50,000 warranty). There were no warning lamps or messages and no symptoms of the problem prior to the failure. A QUICK INTERNET SEARCH SHOWS THIS IS A COMMON OCCURENCE WITH THESE VEHICLES. WHAT DOES IT TAKE FOR A FORCED RECALL?
Complaints are unverified consumer reports submitted to NHTSA. A high complaint count may reflect vehicle popularity, not defect severity. Data sourced from NHTSA public records.
Data synced from NHTSA on Apr 25, 2026