jashin1386

Does any body know where that whistle come from when its below 40 degrees at about 1800 rpm for 05 f150 5.4

'08f150stx

Is it a whistle? If so do you have, a cai? tb spacer?
I would look into alternator bearings.

bruuuuce

Turn your heater OFF when you hear it and see if it goes away, when you have the defrosters on it has the A/C Compressor turning. When I turn mine off the whistle goes away. Have an appointment on the 27th to have Ford check it.