A cam phaser aka camshaft actuator is part of variable valve timing engine.
You should not keep driving with bad ones because can cause engine damage.
It adjusts the camshaft relative to crankshaft to change the valve timing. It is a camshaft sprocket that is adjusted by car computer.
If yours is faulty then you may have these problems:
- Damaged VCT solenoids
- Check engine light on
- Engine knocking
- Poor performance
- Loud rough idle
- Engine ticking
Can be caused by bad or low oil.
The Ford 5.4 3v engines produce a rattle when the variable cam timing phasers can no longer be controlled by the ECU due to wear or lack of oil pressure or volume.
The remedy is to replace cam phaser. This costs $1k-$3k by mechanic, or $400 if do it yourself.