brnr17

That's exactly what mine does too ... i've been wondering what the hell that was ... please post if you get the fix!

SamMcClurg

I wish I could get the problem! Today it was real cold and I was out all day and that's all I heard was the whistling

EBC-150

My '05 had that noise, for me it turned out to be the missing o-ring on the engine oil dipstick, where it was sucking in air. Replacing the o-ring solved my whistle. My guess is that the plastic end contracted a bit when cold, allowing air to flow in. The PCV systems on the 5.4 are 'sealed' with no fresh air inlet.

SamMcClurg

It sounds air related but everything I read about the sound is different

EBC-150

Easy enough to eliminate, just install a new o-ring on the dipstick...

SamMcClurg

Easy/cheap job?

EBC-150

I would say so...just pull your engine oil dipstick out and look at the yellow plastic end. There should be an o-ring toward the top in a little groove. Inspect it's condition, replace if chewed up or not there at all. Pennies for a new one at the hardware store...

brnr17

Well mine's fine ... so what now there problem solver?

Toshbar

Do you have the magic engine noise locating divining rods?

Here is a set for $19:
WOW!!!

tomtom52

Had the same problem. Was a bad idler pulley. Very easy to fix. I went to rockauto and bought a new pulley set and belt. around a $100 if I remember right. Maybe about an hour to replace them. Was teaching my son so my time may be a little off but once you pull the belt its like one nut to pull each pulley. Put the belt on the alternator pulley last is the easiest way to get it on. I suggest going ahead and replacing them all since they all have the same wear.