A8 4.0 Engine Vibration MUST READ!!!
05-27-2017, 02:55 PM
#151
Dealer got the downpipes in on Friday and was able to get them installed same day. I guess the vibration was worse than I thought, because the car is noticeably smoother following the fix. Thanks to everyone here for the info and background on getting this fixed.
06-04-2017, 10:48 AM
#152
So, I poked more at 4.0T TSB's just using Google, realizing there were more than just this one about the vibration. I don't have access to any direct database of them.
Found these 4.0T TSB's so far that got my attention, putting aside the advisory ones only:
The original TSB on which the thread was built has been superseded. They are on at least rev 4. Explained why the old TSB was talking about engine mounts and software revs, yet current thread import is about exhaust. A hunch is there is a yet later rev, maybe just out or soon to be out, that would hit the downpipes square on, But not available where I looked so far beyond the rev 4 that I pulled. Rev 4 starts to get into re-aligning the D4 exhaust as a clue about the downpipes. Attached. Note that TSB is now running all the way to 2015's, so most anyone on this board, A8 or S8, might be affected.
Then I found a variety of other subjects:
The coolant lines to the turbochargers. Guys with older ones (says applies to 2013's), simply pull trim cover and take a quick look. TSB attached.
Then the one about the cooling system that will throw a display warning. 2013's and 2014's A8 4.0T or S8. Gets you a new ECU flash, which I typically like for any running improvements (TDI issues aside...). TSB attached.
The one about cooling system performance. In a code that gets thrown. Leads to new thermostat. 2013 and 2014 4.0T A8's and S8's. I have seen this one in past year on my D3 W12 and did the thermostat myself. Need to get a CEL presumably, which I did along with a variety of other light show stuff when it got really cold in the mountains. Attached.
And the one about the fuel rail pressure... Again 2013's and 2014's 4.0T's, leads to a CEL and then again you get an ECU reflash. I didn't run it down in full, but from further searching this one is also being linked to the "throttle lag" issue some earlier year owners report. TSB attached. Link to AZ post tying it to throttle lag: 4.0TSFI Throttle Lag Solved Popped up here 18 months ago too: https://www.audiworld.com/forums/s6-...2867009/page5/
So far, generally glad I got a 2015 technically, facelift aside. Looks like I need to do the 1K + 3K RPM check myself too. More seriously/regardless of just that one, be aware of the various issues from the TSBs and watch your vehicle for any symptoms. I often position with my service advisor when I know there is a TSB to get the rev made and try to report at least somewhat truthfully the symptoms. Of course with a TSB I am extra sensitized. For the ones that are code based or a check engine light, it has to show up. But then also why when under warranty I don't erase any of this stuff and at most snap a pic of the VCDS screen (and the dash display if anything is flagged there) before heading to dealer.
Found these 4.0T TSB's so far that got my attention, putting aside the advisory ones only:
The original TSB on which the thread was built has been superseded. They are on at least rev 4. Explained why the old TSB was talking about engine mounts and software revs, yet current thread import is about exhaust. A hunch is there is a yet later rev, maybe just out or soon to be out, that would hit the downpipes square on, But not available where I looked so far beyond the rev 4 that I pulled. Rev 4 starts to get into re-aligning the D4 exhaust as a clue about the downpipes. Attached. Note that TSB is now running all the way to 2015's, so most anyone on this board, A8 or S8, might be affected.
Then I found a variety of other subjects:
The coolant lines to the turbochargers. Guys with older ones (says applies to 2013's), simply pull trim cover and take a quick look. TSB attached.
Then the one about the cooling system that will throw a display warning. 2013's and 2014's A8 4.0T or S8. Gets you a new ECU flash, which I typically like for any running improvements (TDI issues aside...). TSB attached.
The one about cooling system performance. In a code that gets thrown. Leads to new thermostat. 2013 and 2014 4.0T A8's and S8's. I have seen this one in past year on my D3 W12 and did the thermostat myself. Need to get a CEL presumably, which I did along with a variety of other light show stuff when it got really cold in the mountains. Attached.
And the one about the fuel rail pressure... Again 2013's and 2014's 4.0T's, leads to a CEL and then again you get an ECU reflash. I didn't run it down in full, but from further searching this one is also being linked to the "throttle lag" issue some earlier year owners report. TSB attached. Link to AZ post tying it to throttle lag: 4.0TSFI Throttle Lag Solved Popped up here 18 months ago too: https://www.audiworld.com/forums/s6-...2867009/page5/
So far, generally glad I got a 2015 technically, facelift aside. Looks like I need to do the 1K + 3K RPM check myself too. More seriously/regardless of just that one, be aware of the various issues from the TSBs and watch your vehicle for any symptoms. I often position with my service advisor when I know there is a TSB to get the rev made and try to report at least somewhat truthfully the symptoms. Of course with a TSB I am extra sensitized. For the ones that are code based or a check engine light, it has to show up. But then also why when under warranty I don't erase any of this stuff and at most snap a pic of the VCDS screen (and the dash display if anything is flagged there) before heading to dealer.
06-04-2017, 12:51 PM
#153
AudiWorld Super User
TSB's are only covered no charge if you have the symptoms and are in warranty (new or generally CPO too). Some owners have some apparent success from occasional threads if they are just off warranty when it happens and/or own a fancy Audi like D4 type, maybe more so if original owner/CPO and not a non Audi sale second or later owner. Then you work through corporate/800 hotline and try to get some cost split/reimbursement.
06-04-2017, 01:32 PM
#154
A couple of observations post-downpipe change:
- I guess my engine vibration was much worse than I thought, because the engine is noticeably much smoother now on upshifts that take it through the 3k RPM range.
- Exhaust has a much deeper sound to it if that makes sense. Not bad or overly loud, just a more powerful sound to it. Anyone else notice this?
Last edited by dwboston; 06-05-2017 at 11:02 AM.
06-09-2017, 04:47 PM
#155
So does anyone know specifically what needs to be updated/replaced/upgraded to rectify this vibration. If I’m in drive I don’t notice it ever. The moment I put it in sport I notice it. And it’s audible. I’m out of warranty so what does this fix run out of pocket??
06-12-2017, 11:17 AM
#156
AudiWorld Member
My 4.2 suffers from this same vibration at 1500rpm, now at 60k miles. I went in to get an estimate to replace the flex pipes at a Tuffy franchise thinking they probably weld a lot of exhausts. They put it up on the lift and looked at it, but but told me that the exhaust on the A8 is stainless and they aren't able to weld stainless at their shop. Does this sound correct?
09-25-2017, 12:14 AM
#159
Audiworld Junior Member
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I have the 4.2 2011 A8 as well. And have similar vibration. At idling and when moving to about 1500RPM Feels really odd
Are you sure the downpipes updates were not for the 4.2? as i dont see another problem with the car
Are you sure the downpipes updates were not for the 4.2? as i dont see another problem with the car
