Another "whats that noise" post

zakimodo · Mar 20, 2022

Hi All, Long time lurker, first time poster.

I have a 2016 RT that has recently started making a noise only when coasting or under very light loads. My wife describes the noise as the engine revving (although its not), I think this is the best way to describe it. I have checked the car for codes, nothing is showing up other than a failed tire pressure sensor.

From the drivers seat, the noise sounds like it coming from the passenger side bell-housing area. Its certainly not coming from behind the front row of seats.

Here is a video. You will hear it start ~45 seconds (coasting to a round about) and then again ~1:42 (light throttle). Curious if anyone else has experienced this.

Don Fox · Mar 20, 2022

Zakimodo:
Welcome to DDN. It's hard to hear anything there. Looking at the odometer (74k), I'd take a close look at the rear drive shaft, and it's center bearing.

Don

zakimodo · Mar 21, 2022

Yeah, the "noise" is hard to pickup on. At first, I questioned if we had just simply not noticed it the last 6 years of ownership.
Its easier to pickup on the tone difference when it transitions out of the noise (1:55 to 1:56). Once you have heard it, its easier to pick up on.

Will take a look at the driveshaft as well.

Tom13DurangoRT · Mar 21, 2022

Kinda sounds like what I would call "rear end whine" but if your DD is AWD could be coming from the front differential too. The sound the splines make while working together. Sometimes they can get louder and audible when the fluid breaks down or otherwise needs to be changed.

I once had a Trailblazer SS that the rear gearset whined from brand new. I drove it about 500 miles before I took it back to them and the result was that the factory didn't put anti-slip additive in the gear oil, or the right version that contains the anti-slip compounds. They replaced the rear gear set and put the correct fluid in there and it never had another issue with the "whining" sounds.

Just a thought.

zakimodo · Mar 21, 2022

I think what I am hearing is what the guys on Ramforumz are calling the MDS tick (MDS tick when coasting). There are quite a few posts/ videos about this with the Hemi-equipped pickups. The symptoms match what I am experiencing. The noise is being attributed to slop in the timing chain.

Chase300 · Mar 21, 2022

Slop in the timing chain? LOL! OK...that's a new one.
I'd start being worried if the noise appears at higher speeds...or changes with speed.

zakimodo · Mar 21, 2022

Chase300 said:
Slop in the timing chain? LOL! OK...that's a new one.
I'd start being worried if the noise appears at higher speeds...or changes with speed.

I think the "slop" is a convenient way to explain one of the symptoms. From what I have been able to research there are a few theories floating around out there as to what the root cause is. Some believe the source of the noise is the tensioner/ chain guide while others point to the cam phaser as the root of the issue.
Many of the people experiencing this issue replace multiple components at one time to resolve the issue (timing chain, guides, and phaser). Unfortunately, that doesn't really help pinpoint the root cause.

Can't say I agree with all of this guy's conclusions, but he has successfully addressed this issue.

Chase300 · Mar 21, 2022

Well I can certainly now hear the noise you're speaking about from the phone located within the engine bay.
Strange....and I can see someone thinking that is the timing chain rubbing. But I didn't see any wear and he didn't point out any...but maybe the tensioner?

zakimodo · Mar 22, 2022

I agree the chain tensioner or guide didn't seem to be in bad shape at all. Along those lines, the tensioner is on the "slack" side of the chain, the cam would have to be "pulling" on the chain for it slap around. I cant see a way in which that happens unless the Cam phaser/aduster is rapidly hunting back and forth?

zakimodo · Apr 8, 2022

Update:

I just wrapped up a test drive after replacing the following:
-Cam phaser
-Timing chain (comes with new crank sprocket)
-Timing chain guide and tensioner (came with the chain)
-Oil pump (probably didn't have to do this, but figured I was already removing to access the timing chain)
-Oil Pan (Because I am an idiot and screwed up the stock one trying to take shortcuts)

The noise is now completely gone. I am confident the source of the noise was the cam phaser. Probably could have gotten away with just replacing it and nothing else.

Another "whats that noise" post

zakimodo

Don Fox

zakimodo

Tom13DurangoRT

zakimodo

Chase300

zakimodo

Chase300

zakimodo

zakimodo

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