So let's find out if anyone else has had a rattle when you start your 4.6L. Like I said my dealer(s) have said it is a cam chain tightener that is adjusted by oil pressure and won't hurt a thing. Does anyone know for sure what this sharp rattle is.

 

I have the same problem when I start up my 1997 F150 4.6L and I have not clue what it is. It only does it the first time I start it for the day. I have heard maybe the cam chain tightener or maybe piston slap? I am looking for answers just like you are!

 

I have talked to several people in the past short while, trying to get to the dottom of this noise since my truck is about to go off warranty. Everybody tells me the same thing "It's the cam chain tightener and it is normal" I was told the other day to get use to it - it will be there untill Ford redesigns their engines. It is not suppose to hurt anything and apparently the V6 engines are much more prone to have it than the V8s.

 

I have a noise nearly every a.m. when I make the first start of the day. To me, it sounds like a belt squeak....but who knows. It seems to go away after the engine is ran at higher rpms to a few minutes. anybody??