Thank you for the reply. This was the first time we did an oil change on this vehicle. We do not know the service history, was it service with the proper viscosity oil (5w20) / interval? Was there sludge in the engine, did the high detergent oil loosen the sludge, causing a cam phaser, which is hydrolically operated and lubricated to fail? Was the damage masked by a heavier oil, took a couple of days for the heavier oil film to wear off, revealing the knock. Known cam phaser problems, can occur at any time.

We did our checks and double checks, RPM check to verify the filter and detect any oil pump problems. The vehicle left with everything operating normally. The anti-drain back valve only keeps the system primed, if it fails, the filter becomes a by-pass filter, there should be no starvation. The Filter was sent to Purolator and found to be 100% to OEM Specifications.

The Mechanic at the dealer said the filter came apart and the gasket was all over the engine. The visual inspection of the filter showed everything present and intact. Is there a source of gasket / rubber insid a 5.4L engine?