my 2016 F250 Super Duty has 8K and the last month or so I have noticed that barking when I first start it and then it goes away?

 

warped exhaust manifold? as it heats up it could be going back into spec. I did notice on my 2017 it does sound different when I cold start it ... maybe an emissions EGR type thing????

 

2011 F250 with 175K miles, mine makes a similar sound and always has since I got it 4 years ago. I just chalked it up to cold start noises.

 

if still under warranty.. take it in.

 

my 2014 does the same thing. i figured it was the band clamp between the cat pipe and muffler pipe being expanded when cold, and shrinking when it heats up and seals.

 

from Ford literature

6.2L 16V SOHC FFV V8 (Super Duty Pickups
and Chassis Cabs)
• Standard on Super Duty Pickups F-250/F-350,
all models
• Standard on Super Duty Chassis Cabs F-350,
all models
• Heavy-duty TorqShift 6-speed SelectShift
automatic transmission is standard on Super Duty
Pickups
• Heavy-duty TorqShift 6-speed SelectShift
automatic transmission with tow/haul mode is
standard on Super Duty Chassis Cabs F-350 with
this engine
Key Features and Benefits
• Flex-fuel (E85)-capable. See the Engineering
Insight on page 2–56
• Large-bore architecture
– Helps improve engine breathing with larger intake
and exhaust valves
– Allows for a shorter stroke design for faster
engine speeds (higher engine rpm) and increased
horsepower
• Single overhead camshaft (SOHC) valvetrain with
roller-rocker shafts allows for enhanced camshaft
design to help provide low-speed torque delivery
• SOHC valvetrain enhances intake and exhaust port
layout and helps improve engine breathing
• Dual-equal variable camshaft timing enhances
the opening and closing of the intake and exhaust
valves during the combustion cycle for a balance of
power, fuel efficiency and emissions
• Two spark plugs per cylinder
– Help efficiently burn the air/fuel mixture in each
cylinder to help increase torque delivery and fuel
efficiency
– Help maintain a smooth idle quality
• Dual knock sensors
– Allow the spark timing of each cylinder to be
enhanced in real time throughout the engine
speed range
• Efficient engine crankcase breathing helps improve
torque capability at higher engine speeds
• Piston cooling jets help improve oil warm-up and
maintain cooler piston temperatures for improved
durability, especially under heavy-duty operating
conditions
• Organic Acid Technology (OAT) orange engine
coolant. See the Engineering Insight
• Fail-Safe Engine Cooling System. See the
Engineering Insight on page 2–57
• Electronic throttle control (ETC) helps deliver
seamless and consistent engine response
• Oil-Life Minder displays the remaining oil-life in the
instrument cluster message center

I BOLD the item.. I think you are hearing at startup...
variable camshaft timing,,,,,, Cycling during engine start up..

 

i think he is hearing a slight exhaust leak when engine is cold, just like i am hearing.
on mine it only last for about 1 minute.

 

on mine.. I hear a deeper exhaust noise within the headers... for 5 to 10 seconds... right after startup..

 

yea, that very well be the cam timing changing.
mine is a definite leak farther back under the truck, in the area of the passenger side seat.