Just wanted to see if anyone has any thoughts on this... When starting my 04 navigator, it has a little clatter at first startup, but settles into very smooth idle, and no symptoms while driving. I know sometimes with DOHC engines this is "normal" since it just takes a bit longer for oil to get up to the cam/valvetrain, but wanted to see if that's typical on these engines, or something I should look into. Just under 150k miles.

 

Clatter is not normal, how old is your oil? What weight are you using? And what brand of oil filter?
99% of the time is due to timing chain guides wearing out or tensioners loosing their prime.

 

We just bought it in November, but service records are complete. Now it has whatever the dealer put in, was changed in December.

It's just a 2 sec thing at startup, maybe I can get a phone video. Tensioners losing prime sounds interesting.

 

I don't know if the 4 valve tensioners is the same as the 3 valve, but mine had a seal blown out on the back side of the tensioner, which would bleed down while the engine sat for longer than 2 minutes, then I would get the chatter you speak of, till the pump filled the void of oil that was missing. For me, it was a second or two max, then all was fine after that.