2003 Navigator at 182k..this noise appears on start up. It progressively subsides after a few minutes.


It improved (less noise now) after an oil change at the Ford dealership instead of other oil change place. I now know that this engine needs a filter with an anti-drain valve.

I would really appreciate if someone could guide me to the right direction to finding the source of this noise. This is completely gone after driving a few miles.

Thank you.

 

It sounds kind of like an exhaust leak to me.

 

To me it sounds like a bearing. Next when cold remove the drive belt then start it and see if the noise is there or not. Don't run it too long because the water pump won't be turning.

 

I agree, I had an 01 f150 5.4 that sounded similar and it turned out to be an exhaust leak. It would also quiet down after it got warm.

 

Thank you everyone. I do remember that one time I was told that the exhaust manifold is in "poor condition". Maybe they meant this. It is not something that could damage anything (else) by leaving it as is..is it?