Yesterday when I turned my fan up,it started making a horrible noise like a growl,and is vibrating badly, you can even hear it outside the truck..This just so happens exactly one day after replacing a coil pak, and a o2 sensor going to the catalytic converter .All this happening at 150k..If I didn't know better I would think all this crap is deigned to happen at a certain mileage, any ideas about the fan noise..oh yeah already replaced the blend door that was a clicking sound,not the same as this

 

anyone ? any ideas?..I swear it sounds like a helicopter inside the cab

 

Bad fan bearing, debris in fan cage, ect, you will just have to remove it and check and see what the problem is.

 

I have an idea: put ALL the truck's details (starting with model year) in your signature so we know what you're talking about.
https://www.f150forum.com/profile.php?do=editsignature

 

 

 

It takes you to the signature of the identity you're logged in as (of course) so you can edit your own signature (of course).

 

I will, but for now it's a 13 FX4 SCrew, 3.5 eco, 6.5 bed

 

no warranty