patrickb

I had been experiencing the same rattling downpipe issue in my 2019 Q7 Prestige for the last several months. At 44,000 miles, I took it to the dealer for diagnosis, TSB in hand. Rode in the car with the shop foreman driving; he didn't experience the issue but stated that he would be able to see any vibration once the car was on the lift. My service advisor called later in the day and said that parts were being ordered and that they had never experienced a customer providing them with a TSB as a heads-up. Both brackets and both downpipes were replaced under warranty.

cmarcks

Can anybody with this issue please describe the sound or post a video? I have three 2017 Q7s and my original with 130k just started making a sound I can only describe as similar to a bad timing chain/broken guides rubbing on metal... a fairly quiet ratcheting type of sound seeming to be happening on deceleration under 2k RPM but can be heard from insudecwhile driving or from outside while parked. I haven't poked around with the stethoscope yet but everything seems to otherwise be operating fine. Was your noise something that could in the beginning fool a guy into thinking it was engine internal? I'll pinpoint it this weekend and report back thanks

mhoran89

this issue is different than the downpipe vibration felt through the chassis at lower RPMs, that is covered in another thread on here...

cW6mT mKviGLi

- First time at around 30k miles I was having a vibration and resonance issue at around 1500rpm where it sounded like a home theater subwoofer rumbling (trying to reproduce a low frequency note below 25hz). Downpipes were replaced

- The second time at 46k miles. Noise occurred around 1k RPM where it sounded like cards in bicycle wheel spokes. Downpipes, hangers and brackets were replaced

- The third time at around 47k miles. Same noise as the second occurrence. No more replacements covered by AOA because the day before my appointment my Q rolled into the 50K mile territory.

mhoran89

I now definitely have this and the car is at the dealer as of this morning. Going to get this checked out and will report back. It seemed to have it on startup like 2 years ago but now it is happening during deceleration.

bluesmoke

Im starting to hear this too on mine
Gutted to hear that CPO doesnt cover this...if thats the case, I may look at customer DP with different flex pipes if at all possible

gbgastowers

I bought this kit a few years ago. I heard it was an updated part to cure the rattle I had under the firewall area of exhaust (down pipe). I haven’t installed yet. Gunar

IntheQ5

There aren’t any updated or revised for the parts you mentioned above. At first i thought it was loose particles in the resonator as hitting it with a rubber mallet made some rattle noise. After removing both sides to check it out, it’s very clearly that the flex section have too much play. I remove the outer wire mesh and put 2 stainless steel worm clamps on each side to tighten the sloppiness but just enough to have some wiggling for vibration. No more rattles. Used to rattle like a rattle snake going downhill off throttle on the same road near my house.

btw if you do decide to remove the resonator out for any reason. Buy new connecting coupler clamps that connects to the rear exhaust. The nuts will break and even if you get new bolts and nuts, it will never seal tightly and will result in exhaust leak.

mhoran89

do you have a picture of what you did to the flex sections of the downpipe?

I looked it up yesterday online and it is about $800 in parts including shipping to get this fixed. the labor is pretty minimal....

IntheQ5

Pretty much what it is , just clamp tighten so the flex rings doesn’t move as much. I forget what size as i took a piece of string and went to homedepot. Probably 4-5 inch.