Pulsing RPMs while driving

[Jknapp1]

I've got a 2021 Powerboost and lately I've noticed an intermittent humming and slight vibration while driving at highway speeds. It happens while the engine is under load going up any slight incline. Today I noticed the RPMs pulsing with the noise and vibration. Does anybody have a thought on what this could be? I got a video of the tachometer while its happening but you can't hear the noise.

Sponsored

 

[Riddick]

Very hard to diagnose on the internet. Assuming you are applying a constant pressure to the accelerator I would guess its an issue developing with your torque converter.

 

[Jknapp1]

Yeah, constant pressure is applied. It doesn't do it while coasting.

 

[JayRay]

Have you had the BCD drum in the transmission replaced with the new design that doesn’t allow the drum to slip in the transmission? Mine would occasionally surge in RPMs for a few seconds under load on the highway. The BCD drum replacement fixed the issue. Mine is also a 21 PowerBoost and I had it replaced around 80,000 miles.

 

[Jknapp1]

I have not. Im at 73,000 myself. The transmission also clunks sometimes shifting into gear. The shifting has gotten back to sporadic while driving too. I once had them reset the trans a couple of years ago for the hard shifting.

 

[Jknapp1]

Are you referring to the CDF drum?

 

[JayRay]

Are you referring to the CDF drum?

Sorry, I definitely meant the CDF drum. I must not have had enough coffee.

Sponsored