6.4 eco

[tim9613366]

My 2019 2500 HD 6.4 is making a heck of a rattle (almost resembles spark knocking) when it goes into eco mode in city traffic (45 mph or lower). At high speeds, it will occasionally sounds like an exhaust issue (almost resembles a bad cat converter knocking...it's loud). Also, there's never any drop in rpm's according to the tach. I carried it by the dealership and made them ride with me so they could hear it. They were dumbfounded...no idea what it might be. Also...every now and then with no rhyme or reason, when I first start the engine, it knocks like a cylinder issue but goes away after about five seconds. I videoed the startup knocking noise so they could see and hear it. They said the oil pump was probably bad, but that should have been noticable in the oil pressure gauge, but it wasn't. BTW, it's been serviced routinely by the dealership. It's kind of hard to describe the noise, but even the mechanic said it was definitely there. They said they were going to do some research and get back with me...that was two weeks ago. So, in essence, my question would be has anyone else had issues with eco such as this? Thanks

 

[Eatonpcat]

I hate when mine goes into the 4 cylinder mode when I am driving slow...Makes a horrible sound!!

 

[LateToTheParty]

Any chance you can get and post a recording of what you're experiencing?

What may sound like a "heck of a rattle" to you may sound like, as I've seen posted before "a helicopter landing on my cab", "my exhaust fell off", or "a horrible sound" as Eatonpcat mentioned above.

I've had multiple passengers ask me what the heck that noise is when mine kicks in, but at least for the sound that mine makes, it is the same as on all others that I test drove (just a little deeper now that I've changed my exhaust).

 

[Squatch]

If I were you I would go test drive another 6.4, give it a cold start and see if it makes the same sound at start up and in eco mode.

 

[Epsilon Plus]

Do you have an aftermarket muffler?

In the GM world, the "MDS" trucks had a flapper valve inside the muffler for 4cyl mode. When people changed the muffler out, the flapper was gone and you heard complaints of similar symptoms. Basically putting a 3.2L 4cyl through 3" exhaust. Sounds a lot like you'd imagine.

 

[Rockcrawlindude]

Mine sounds different in “eco”. It is a deeper tone, sometimes sounds like it’s lugging.

I have noticed sometimes it can sound like detonation or pinging if I roll into the fuel slowly enough for it to try to accelerate without coming out of “eco” mode or downshifting. These are normal sounds for the circumstances

 

[r440]

I have a 2019 Ram 1500 that made a noise when in eco , complained to my dealer and there was a flash for that and has been good since , it was something to do with noise cancelling module