Vehicle: 2011 Chevrolet Malibu, L4-2.4L, Automatic Transmission
Problem: The vehicle was brought to the shop because the MIL was on and the engine ran rough and stalled. The technician checked the fuel pressure and it was within factory specifications. He was unable to keep the vehicle running long enough to see any difference in the camshaft timing “actual” versus “desired” PID. He also retrieved the numerous DTCs listed below.
P0011 – Intake Camshaft Position System Performance
P0014 – Exhaust Camshaft Position System Performance
P0068 – Throttle Body Airflow Performance
P0101 – Mass Air Flow (MAF) Sensor Performance
P0106 – Manifold Absolute Pressure (MAP) Sensor Performance
Details: The vehicle’s engine looked poorly maintained and had high mileage on it so the technician removed both actuator solenoids for inspection. He found massive amounts of debris and sludge on the actuator screens and in the hydraulic passages located in the cylinder head. He double checked the actuator control circuits just to make sure they were operational. They were good.
Confirmed Repair: He cleaned the passages and replaced both camshaft position actuator solenoid valves. He also changed the engine oil because it was extremely dirty. After the repairs, the technician cleared the DTCs and test-drove the vehicle. It ran well and the MIL remained off.