Engine rattling prior hto turning on

[Steve Razo]

In April of 2019 I purchased a new 2020 Raptor. I have 23k miles on it, I had two factory recalls completed which include the PCM reprogram due to engine shutter and Cam Phasers. Recently I noticed when the truck sits for over two days and I turn on there's a rattling noise coming from engine compartment then disappears when engine turns on.

 

[FordTechOne]

So the noise is occurring before the engine is running? If you only turn on the ignition without starting, the PCM does a bunch of self tests which actuate components and result in various noises; that’s normal.

If there is a 2-5 second rattle/clatter type noise from the timing cover as soon as the engine starts, that can be caused by cam phasers.