humblepie

Greetings all! heck of a first post to make I know.... but I want to contribute to the ticking Lt1 debate. To me this sounds more like a rocker or lifter than an injector cycling or anything relating to mechanical fuel pump. 1100rpms and then 1800-2500rpm in cabin while driving. Deceleration and acceleration both noticeable. One dealer has said "normal DI noise" one dealer has requested I leave it with them next week for more investigation. What do you guys think?. The motor looks to be healthy on the local dyno it make 436 and 441 compared to my C5z that made 375 and 360. Best to hear with head phones.

Pineapple

I agree, it doesnt sound like your typical DI ticking. DI ticking is only audible at idle and goes away once you give it gas. I’d leave it with the dealer to diagnose the problem. I doubt it’s the valve train, it might be something as simple as a loose clamp at the exhaust.

humblepie

as an update dealer has since diagnosed this as an issue with the torque tube and drive shaft? Im really not sure about this one folks.

Bill Dearborn

If you have an M7 disengage the clutch and see if the noise goes away. Since the clutch is mounted to the back of the engine with it disengaged the drive shaft doesn't rotate and shouldn't be making any noise.

Bill

humblepie

Thanks Bill, I have had the same result as far as the ticking noise with the clutch pedal in/out, accelerating/ decelerating, in neutral and in gear. Im really not interested in the dealer picking random parts to replace. They are saying the other 2019's on the lot do not make the noise as recorded above.

lisl12

My 2017 A8 GS has this "ticking" as well at these RPMS..dealer told me the other ones had it that they compared to..

fishpick

It's a "new normal" sound for 2019's. All the 2019's do it in that RPM range. In addition to all the improvements in the 2019, they play with sound deadening material changes / locations / thickness / shapes, etc as well... and something got changed that makes the pump more audible in this range of RPM's. It's a variation on the classic sewing machine sound DI pumps make - and it's always in that RPM range - never above - never below - never louder. Trim levels may change the perception - but it's there. More audible in the cabin than outside the car. And like anything mechanical with tolerances - some variability in volume and the range of RPM's - but it's NORMAL. AND... some peoples hearing is more sensitive to the sound than others - so in my c7 - I have had passengers that ask what it is - and I have had passengers that can not hear it - when it's clearly audible to me. So if you hear it - then your ears need to be the ears listening to other cars.

Also - it's not a LT1 only "feature" the LT4's make the exact same sound.