The 2017 Mercedes-Benz GLS 550 had engine misfire and vibration affecting the first two cylinders. As part of the completed repair, two faulty fuel injectors, two spark plugs and two ignition coils were replaced, and the oil-contaminated wiring harness was cleaned. The misfire and vibration were resolved, and the vehicle was returned to normal operation without the related faults returning.
Customer Concern
The engine was running unstable with vibrations and misfiring, specifically the first and second cylinders were not working properly.
Work Performed
Compression measurement; Inspection and replacement of two faulty fuel injectors; Inspection and replacement of two spark plugs; Inspection and replacement of two ignition coils; Endoscopic inspection of cylinders; Cleaning of oil-contaminated wiring harness; Diagnostic error reset and verification
Verification & Result
The misfire and vibration issues in the first two cylinders were resolved by replacing two fuel injectors, two spark plugs, and two ignition coils. After cleaning the oil-contaminated wiring harness and resetting errors, the vehicle runs perfectly without returning related faults.
