Cold Weather Idle Whine 6.7L
 

Hi all,

Looking to see if anyone else with a 2017+ 6.7L PSD has had a cold weather whine/squeal at idle or high idle (750+ Rpm)? I have attached a video below showing a it. It seems to happen when weather is cold out (-5f to -15f that is was today).

The truck is always parked in a heated garage at night, and it does not make the noise when I first take it out, but after it has been outside for a while (whether or not it has running and driving the entire time) the noise eventually starts when it's this cold.

I just had it into Ford today, but they were unable to figure anything, and it goes back in tomorrow. I am just looking if anyone else had any insight I could possibly give them. Thanks in advance! Video below.

Whining
Uncles Non-whining 6.7L for reference:

Yup, I've had that. Almost seems like the belt is loose. But, once it warms a little, it goes away.

Hmm, mine take alot for it to warm up and go away. I have my high idle wired in to idle at 1100 rpms, which gets the engine easily up to operating temp, but it will still sit all day and squeal. It only seems to go away after semi aggressive driving, but then will return when the truck cools down a bit idling stationary again.

Mine does it also but only below 15 degrees or so. I thought maybe it was the engine calling for def. Because I've heard def freezes around that temp. It only does it for a few seconds on mine at first start up. I first experienced it while hunting and the temps were below 0. As I ran to the truck thinking there was something wrong, like maybe gelled fuel it stopped by the time I got there. I've probably experienced it 4-6 times in the last month or so. It doesn't happen every time or since the bad cold front has left.

Well just got the truck back from the dealer the second time, and all seems to be fixed. They replaced the belt and fan clutch, and when I picked the truck up it seemed to be cold enough outside, and no noise was to be heard.

Apparently on 2011-2016 6.7Ls the fan clutch was a known issue, but they were supposed to have been updated for 2017+, maybe I just got leftover parts lol.

Anyways we will have to see on the next extremely cold day, and if it's gone then I will be able to rest easy.

Kinda sounds like the beginnings of my noise.... 2017 250 6.2L.... ended up being a Fan Clutch... said it was running full on all the time. only when cold starts (40F) and below

It did turn out to be the fan clutch, they must be shared between 6.2 and 6.7. Thankfully I haven't heard it again so far, so hopefully the issue is solved.