[3.5EB]

Over several months I've been doing a lot of digging into this rattle 2nd gen 3.5s and 5.0 Coyote V8s are becoming notorious for. One day I decided to make a video on this (along with the many videos already on YouTube), and I've discovered some interesting things that lead me to believe cam phasers are not the cause of this specific rattle under these specific conditions. The truck is a 2018 assembled in early August 2018 and had 25K miles when I filmed this.

First, the rattle can only be heard when the engine is cold and eventually goes away with time. Everyone knows that.

Second, it can only be heard in Drive and Reverse and M. It cannot be heard at all in Park or Neutral. Something I didn't realize.

Third, it can also be heard when CHANGING GEARS, such as P to R, R to D, etc., with my foot not even being on the gas. Listen very closely from 2:17 to 2:20, 2:53 to 2:56, 3:16 to 3:26 to hear instances of this. This was something I especially was surprised to discover, as I've never heard it under these circumstances.

There is a ton of confusion relating to this issue. Virtually every YouTube video, media post I've come across, the owner suspects or has been "told" by the dealer it's the VCT units/cam phasers that are to blame and need to be replaced. I challenge that assumption with this: If that's the case, why can I only hear it in gear? If it truly is engine-related, the noise should be heard regardless if the vehicle is in gear or not.

Then there's the software debate, arguing software is bad and is causing the rattle. I challenge that assumption with this: If that's the case, why can I hear the noise when changing gears with my foot not on the gas?

With this evidence, I don't think (at least with this truck) the noise is related to cam phasers at all. I think it's transmission related. Of every report I've read relating to this issue, whether it's the 3.5 or 5.0 (or possibly the 2.7, which I don't know a lot about), they all have something in common: they have the 10R80. My theory is a part(s) relating to the transmission is very sensitive to expansion and contraction and is engaging (foot on the gas) and disengaging (foot off the gas). As the transmission reaches operating temperature, the rattle goes away, not relating to the engine reaching operating temperature.

And think about this: so many owners have already taken their trucks in to try to get this problem fixed, whether it's new cam phasers or timing chains or software updates or whatever. And after they get their truck back, surprise! The noise is still present! Have the dealers been replacing the wrong parts this whole time?

Skip to 1:40 if you want. That's where I start experimenting. Watch from the beginning to hear the cold start.

 

[snakebitten]

Whether you're theory proves one way or another, I am totally convinced that not only some of the various "noises" that our trucks might make are related to the transmission, but also some percentage of the shudders/shuddering and vibrations.



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[TurboGT]

I Have seen a few instances of this referenced but have not done any in-depth reading on the subject.
That being said, have any of the people who notice this noise actually experience a failure of any sort?
Is it just a characteristic of the vehicle and nothing more than a superficial Noise? Every design change will have new characteristics that arise, detrimental or not. I'm just curious If its something people are perceiving as a problem when it's just a characteristic?

 

[snakebitten]

There certainly seems to be a recent increase in 10r80 torque converter, transmission pump (gear driven & electric), and a few mount failures.

Like all forum reports, it's difficult to equate that to any kind of percentage of trucks affected since often these reports are the reason the member joined. But as the 10r80 starts to rack up some real world field miles, it's perhaps going to reveal some of its potential failure points.

I've also heard from some of the guys who have been into theirs for high-horsepower builds, that even the ones that weren't exhibiting any symptoms or problems, once they opened them up they had some wear points that could be a concern.

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[DNA Dan]

As a casual observer of your comments with no skin in this game, what you describe is a transmission/driveline related issue. If it was anything to do with the motor, you would hear that ALL the time. The phasers work the same whether the truck is in idling or in drive, or park, 5000 RPM, etc. The operation is the same. Now that's not to say it's the transmission itself. These are complicated systems, and it could be the case that when the truck is in drive, there's a valve, clutch, solenoid or something that shuts off or "switches". That could be what's making the noise and the mechanics of the transmission could actually be fine. Whether this is something that is an indication of a future failure, I guess time will only tell unless you can pinpoint where the sound is coming from.

 

[Tomato001]

Any updates on this issue? im trying to help the ford dealership to find the problem cause i have this exact same issue already timing chains replaced and didnt help at all truck is currently with 75k miles