Passenger-side Engine Noise 3.0T

[MyDimeIsUp]

Got a question for everyone here. I was listening to the engine of my 3.0T when I heard this "chugga" sound from the passenger-side bank. Now I do remember that when I was In the market for C7 A6s last year, I was inspecting a car and it made this exact sound on the passenger side. Anybody know what this sound is? Must be somewhat common for the 3.0T since the car I inspected last year as well as my current A6 both made this sound. The video of my car is with the engine already warmed up and the video of the A6 I was looking at last year was a cold start.

My A6


2022 A6 I Inspected

[MyDimeIsUp]

Giving this a bump

[Valpo A7]

Almost sounds like a noisy fuel injector.

[MyDimeIsUp]

Almost sounds like a noisy fuel injector.

I feel like the sound is much quicker than when the FI would be spraying fuel in. Also the chugga seems to be a deeper sound.

[MyDimeIsUp]

Also took a second video which may be a little better. I move from the front to the rear of the engine on the passenger bank and squeeze my phone by the upper timing chain cover (doesn't sound like its coming from timing chains/guides though). Maybe others can record what their engine sounds like and post it here? Ignore the purge valve clicking, that is not the sound I'm talking about it just happen to be going while

[MyDimeIsUp]

Bought a stethoscope as per Valpo's recommendation on AudiWorld and the "chugga" sound seems to be coming from the HPFP. I have no clue why it's that loud but makes sense that three Audi's I've checked out have made this exact sound on the passenger-bank. Just a lot louder than my EA888 2.0T