Weird noise - any ideas from my video?

[mculik5]

I have a 2021 Ram 1500 5.7, no eTorque. It has about 15K miles on it. I recently changed the oil for the second time (Pennzoil Ultra Platinum 5W-20) and installed a Pacbrake oil filter relo kit. No leaks or anything like that, and my temps and pressure are normal.

Just a few days ago, I noticed that if I accelerate quickly (not full throttle, but faster/harder than I normally do, such as when pulling out in traffic or going up an on ramp), the truck starts making a humming noise AFTER I come off the gas. For a description of the sound, the first time it happened, I legitimately thought there was Honda Civic with an exhaust can or a sportbike next to me and got all confused when I couldn't find anything in my mirrors. Subsequently, I noticed that the sound can be felt through the steering wheel and gas pedal - not like something is physically vibrating those things, but like they are transmitting vibrations coming from the engine compartment.

Here's a video -

. The noise starts at ~1:30 mark, after I accelerate hard.

I didn't show it in the video, but I checked my tire pressures just to be safe and all four were showing 37 PSI. I'm in NJ and it's been a bit colder, but not crazy - more or less mid-20s to mid-30s. As I mention in the video, the sound doesn't seem to be dependent on the truck being warm or cold. The sound is also not correlated with throttle position or truck speed. As an example, I have a long driveway and accelerated hard down my driveway. The sound happened just like in the video, and it continued at the same frequency/volume until I slowed (using the brakes) to about 2MPH and then it just abruptly stopped.

For what it's worth, I haven't felt any shuddering or slipping or hard shifts or anything like that.

Any ideas? Thanks.

 

[aaronYork]

I do notice your lane assist light change colors on your dash as you says the noise. Does that play a auditable noise through the speakers or would it viberation?

 

[kapinallinen2]

I have a 2021 Ram 1500 5.7, no eTorque. It has about 15K miles on it. I recently changed the oil for the second time (Pennzoil Ultra Platinum 5W-20) and installed a Pacbrake oil filter relo kit. No leaks or anything like that, and my temps and pressure are normal.

Just a few days ago, I noticed that if I accelerate quickly (not full throttle, but faster/harder than I normally do, such as when pulling out in traffic or going up an on ramp), the truck starts making a humming noise AFTER I come off the gas. For a description of the sound, the first time it happened, I legitimately thought there was Honda Civic with an exhaust can or a sportbike next to me and got all confused when I couldn't find anything in my mirrors. Subsequently, I noticed that the sound can be felt through the steering wheel and gas pedal - not like something is physically vibrating those things, but like they are transmitting vibrations coming from the engine compartment.

Here's a video -

. The noise starts at ~1:30 mark, after I accelerate hard.

I didn't show it in the video, but I checked my tire pressures just to be safe and all four were showing 37 PSI. I'm in NJ and it's been a bit colder, but not crazy - more or less mid-20s to mid-30s. As I mention in the video, the sound doesn't seem to be dependent on the truck being warm or cold. The sound is also not correlated with throttle position or truck speed. As an example, I have a long driveway and accelerated hard down my driveway. The sound happened just like in the video, and it continued at the same frequency/volume until I slowed (using the brakes) to about 2MPH and then it just abruptly stopped.

For what it's worth, I haven't felt any shuddering or slipping or hard shifts or anything like that.

Any ideas? Thanks.

So that noise appeared after installing the remote filter kit?
My WAG is that the oiling system could be resonating under set conditions, because of the new configuration.
If that was the case, then you would hear and feel it due to the filter being hard mounted to the frame.
I would isolate the filter and mounting bracket assembly from the frame and see if it changes anything.
Just my two pennies...

 

[mculik5]

@aaronYork - Sharp observation, but that's not it.

@kapinallinen2 - That's VERY interesting thought.

I have a tractor with hydraulics. I usually shut it off with the bucket off the ground and then lower the bucket to reduce the pressure in the system when I'm not using it. Under certain circumstances, you can hear the fluid whistling through the valve galleries.

I just did some googling, and it seems like engine oil flow rates are quite high. At high RPMs, the flow rate would be way up, along with the pressure and the the velocity in the lines. Then, when I lift off the gas, all that excess pressure bleeds off by racing through the lines, but since the system is no longer "bound tight" by the higher pressure, it vibrates due to the flow velocity.

If this is correct, I should be able to recreate the condition with the truck in park, unless the resonance is some weird combo of oil filter vibration and frame vibration due to being moving. If I can't recreate it in park, maybe I'll unbolt the filter mount, zip tie and drive around my neighborhood to see if that makes a difference.

Thanks for the input.

 

[kapinallinen2]

@aaronYork - Sharp observation, but that's not it.

@kapinallinen2 - That's VERY interesting thought.

I have a tractor with hydraulics. I usually shut it off with the bucket off the ground and then lower the bucket to reduce the pressure in the system when I'm not using it. Under certain circumstances, you can hear the fluid whistling through the valve galleries.

I just did some googling, and it seems like engine oil flow rates are quite high. At high RPMs, the flow rate would be way up, along with the pressure and the the velocity in the lines. Then, when I lift off the gas, all that excess pressure bleeds off by racing through the lines, but since the system is no longer "bound tight" by the higher pressure, it vibrates due to the flow velocity.

If this is correct, I should be able to recreate the condition with the truck in park, unless the resonance is some weird combo of oil filter vibration and frame vibration due to being moving. If I can't recreate it in park, maybe I'll unbolt the filter mount, zip tie and drive around my neighborhood to see if that makes a difference.

Thanks for the input.

Yes sir. Zip ties and duct tape.

 

[Jake1050]

That is your empty washer fluid tank resonating with the engine sound.

 

[Scram1500]

Could be a malfunction in the ANC system (active noise cancelation)

 

[cerbo]

I don t know how long or hard it was to install the oil kit but considered putting it all back to OEM and know for sure if it s the kit. If it happened right after the kit install then that would be my guess.

 

[Wild Bill]

Sorry, I couldn't resist...
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