2017 F-250 CCSB 6.2L 4x4 w/ 2.5" (proper) level and res/muff delete. Bought at 8,200 mi. now at 15,100 mi. I switched to full synthetic at 8,500 mi. I'm not sure if it was doing this when I bought it or not, but it has been doing it for a while now. I only notice it when pulled up to a drive-thru or sitting in my drive next to my other truck. This is my first vehicle with cam phasers, so I'm not familiar with w/e noise they might bring to the table. I do occasionally hear the lash adjusters / lifters doing their thing, but it always clears right up.

On cold start or after sitting for a few hours, it is smooth and silent. After it idles down to full-temp idle speed, it immediately starts doing this at random. It is directly related to engine speed, but SEEMS to go away with higher, off-idle RPMs. It sounds to me like it's coming from the center of the big end and it carries all the way down the drive line. Loudest between rear of motor and trans. You can't feel the knock though at all, everything feels as smooth as butter.

(Sorry about the cicadas. The sound is a LOT better on my S9 than my laptop. Oddly, I can't even pick it out using earbuds on my workstation.)

https://drive.google.com/open?id=1-7...ANxJVfxulEiu5d

https://drive.google.com/open?id=1-I...Cwiyj2-TQyHeJN

Thoughts? Does yours do this? Could this possibly be related to the CPV / Cannister Purge Valve or is that more of a ticking? Rod knock?

 

piston slap??

 

Still under warranty?

 

Sure, but we all know how that goes. I'll mention it at next oil change, but they are rarely impressed with noises. I'm sure they only chase fault codes and driveability issues.

 

Try a different dealer. That doesn’t sound normal.

 

My 2017 6.2 20k miles makes this noise too..under the exact circumstances that you described. FWIW, at my 15k mi oil change, I sent a sample to blackstone for analysis...nothing came back abnormal...but don’t know if that means anything or not.

 

..but mine doesn’t seem to be as loud as yours.

 

Thanks MJAB.

 

I don't think it's anything mechanical. Sounds like an exhaust leak to me.

 

Because of the fan blowing it's always hard to hear where a noise is coming from. When I first got my 2013 6.2 I had a very similar noise and it still does on occasion. I found it was coming from the serpentine belt when cold, on mine I could look through the wheel well on the drivers side and see the belt jumping in time with the noise.

Denny

 

I've tried holding the brake and pressing the accelerator to see if the noise increases but it immediately seems to go away as soon as the engine comes off idle. But yes, just like your example, my truck never does it cold...only after it's up to full operating temperature and idling. Sound becomes apparent right as the RPM bottoms out at idle. I have no idea what it is.

 

It definitely sounds more like a knock than the tick of an exhaust leak. It also does seem to follow RPM, but much over idle speed and yes it does seem to go away. I towed a trailer 600 mi. on Saturday and I didn't hear a peep out of it all day. If Ford doesn't want to do an oil analysis on it, I may do one myself. Will report back once I do for sure.

 

If it's intermittent, it is not a rod knock or wrist pin. I still think it's an exhaust leak because you state it comes on when warmed up. Metals often expand enough to open up gaps between the gaskets when the engine is at operating temp.

I can almost bet your oil analysis will come back squeaky clean.

 

Also, you might want to find a long screwdriver/rod and use that as a stethoscope, by holding the tip to various parts of the engine, while resting your ear on the end. I'd start with the exhaust manifold.

Obviously pay attention when you have it near the accessory belt.

 

I've definitely been meaning to do just that DSLTRK, we've been busy Mustang shopping. I would agree that the conditions would make one lean toward exhaust manifold leak, but it's definitely a knock from the bottom, center of the engine and not from one side or the other, but sounds do odd things so I wouldn't rule anything out just yet. Was relieved that I couldn't feel the knocking what so ever. Will report back, may dry out enough today to get back under there and check.