Some 2019 Enclave and Traverse models may have an illuminated Check Engine MIL along with an engine ticking noise, coolant loss or very dark colored oil in 3.6L V6 engines (RPO LFY) with low mileage. DTCs P0016 (Crankshaft Position – Intake Camshaft Position Not Plausible Bank 1), P0017 (Crankshaft Position – Exhaust Camshaft Position Not Plausible Bank 1), P0018 (Crankshaft Position – Intake Camshaft Position Not Plausible Bank 2), or P0019 (Crankshaft Position – Exhaust Camshaft Position Not Plausible Bank 2) may be set.
These conditions may be caused by coolant contaminating the engine oil due to internal porosity on the cylinder head at the outer bolt area. Check the engine oil for a dark color or sticky feeling. The engine oil condition has a major impact on the camshaft actuator system. Debris or oil contamination can interfere with the camshaft position actuator solenoid valve and the mechanical camshaft actuator operation.
If these conditions are found, remove both camshaft covers for access to the top of the cylinder heads. Pressure test the cooling system with up to 20 PSI (138 kPa) while watching the center two head bolt area on the exhaust side of the heads. Observe the area for approximately 15 to 30 minutes, looking for a leak that may be moderate (Fig. 17, #1) or extreme (Fig. 17, #2) from the affected area.
Fig. 17
If bubbles or coolant foaming is seen in the center two head bolt area, the cause may be porosity on the head bolt cutout area or column, which will require replacement of the affected cylinder head. (Fig. 18)
Fig. 18
Refer to #PIP5674 for additional information.
– Thanks to Aron Wilson
