"Is the Glc 400d reliable, and what should you check?"
When buying a used 2022 Mercedes-Benz GLC 400d (253 / facelift), the most frequently mentioned issue is EGR clogging and carbon buildup. High oil consumption is also commonly reported.
Engine: OM656
OM656.929 · diesel · 400d · Used in this car from 2019-2023
Known engine issues
Camtronic variable valve timing issuesMost problems are related to the Camtronic variable valve timing system.
Camtronic actuator replacementWhen it fails, the drive solenoids, controlled camshaft, and rockers are replaced.
Fuel system sensitive to poor dieselDoes not tolerate poor diesel fuel; the CR Bosch CP4 fuel system with piezo injectors is affected.
+2 more issues on the engine detail page
Known issues and risks
Listed from most frequently reported, each with its source.
EGR clogging and carbon buildup
Often reported
In the OM656 engine, carbon buildup can occur in the EGR system and intake ports, especially during city or short-distance driving, leading to power loss and rough idle.
Engine Bay
High oil consumption reported
Often reported
Numerous technical reports and user accounts indicate above-average oil consumption cases in the OM656 engine, requiring more frequent oil top-ups. If excessive oil consumption is not monitored, it can lead to lubrication issues and damage to the turbocharger or other mechanical components.
Engine Internal
Camtronic variable valve timing system issues
Often reported
The Camtronic variable valve timing system in some OM656 variants can fail due to wear on actuators/solenoids or control components, leading to timing errors, rough idle, and reduced performance.
Engine Internal
Fuel system sensitivity (CP4)
Often reported
The OM656 engine uses an advanced Common Rail system with a CP4 high-pressure pump and piezo injectors. The system is sensitive to fuel quality: water, contaminants, or poor-quality diesel can cause premature wear.
Fuel System
Turbocharger failures or wear
Often reported
Turbocharger failures in the OM656 engine have been reported due to inadequate lubrication, oil contamination, or thermal stress.
Turbo
Mercedes-Benz Glc 400d technical specs
Mercedes-Benz Glc 400d (2022): boot 550 L; fuel use 7 l/100 km (urban 8,5 l/100 km · extra-urban 5,7 l/100 km); 0–100 in 5.1 s.
Boot capacity
550 L
Fuel consumption
7 l/100 km (urban 8,5 l/100 km · extra-urban 5,7 l/100 km)
What should I look for when buying a Mercedes-Benz GLC 400d?+
When buying a 2022 model 400d, check the service history, perform a test drive, and inspect engine/transmission warnings. Most commonly reported issues: EGR clogging and carbon buildup; high oil consumption; Camtronic variable valve timing system problems.
What are the chronic problems of the Mercedes-Benz GLC 400d?+
Most commonly reported issues: EGR clogging and carbon buildup; high oil consumption; Camtronic variable valve timing system problems.
Is the Mercedes-Benz GLC 400d reliable?+
Rather than a simple yes or no, it's best to weigh the proven pros and cons together. This page lists 5 verified findings.
How does Carbeak collect data?+
The cards on this page are derived from the Difetti fault database; the source vehicle is matched to the target vehicle by brand, fuel type, engine, and generation. Topics with insufficient evidence are not shown.