Nocking sound when accelerating hard 2000 Audi


Asked by Nov 30, 2013 at 05:05 PM about the 2000 Audi A6 2.8 quattro Sedan AWD

Question type: Maintenance & Repair

2000 Audi A6 quattro, usa, automatic (with sports +/-)

There is a repedative nocking/thudding sound when I accelerate hard (foot to the floor) the sound seems to be throught the car as if the driveshaft was hitting (My very novice way of describing)

The problem does not happen if i accelerate at an average or slow even if i use the sports shifting and ride the gears out to just before redline before shifting.

I have plenty of tools and a decent knowlege of what to do with them.
Any help would be apreciated!
Check engine light is off and my OBDII doesnt detect any problems

5 Answers

this would indicate a LEAN condition....the EGR does engage when operating temperatures get too hot...this would cause this problem when HOT? suspecting a sticking EGR might try pulling the vacuum source to the EGR and puttin' a golf tee in the suction part of that...see if this does anything....might help find the culprit~

this one still has a vacuum advance on the distributor (I think, would have to look it up) see if this exists and operates normally~

timing too far in advance can also cause this knocking...Octane too weak to do the job too can do this~


Thanks for all the help! Ill be sure to test your ideas, in answer to your question, i would hesitate to say it was in hot temperatures, i'm currently running the car in freezing temperatures (floating around 32) in the mountains of Colorado. Something to note, the knocking does not happen if i am sitting on the driveway in neutral/park and revving (as if i where when i hear the knocking) Would the EGR only be operational when in gear/driving?


Check drive shaft going to rear diff' most likely the carrier bearings on shaft are going bad, they are mounted in rubber mounts, just did a 2007 ford fusion all wheel drive, sounded like the bottom of car was trying fly apart when going down road, but not make a noise sitting in driveway, you. might have to put it on hoist to check for sure, EXPENSIVE.

1 of 1 people found this helpful.

Your Answer


Looking for a Used A6 in your area?

CarGurus has 7,779 nationwide A6 listings starting at $2,200.


Audi A6 Experts

  • #1
    Tom Demyan
  • #2
  • #3
View All

Related Models For Sale

Used Audi A4
197 Great Deals out of 12,429 listings starting at $1,500
Used BMW 5 Series
401 Great Deals out of 16,252 listings starting at $1,650
Used Audi A8
42 Great Deals out of 1,450 listings starting at $3,499
Used Mercedes-Benz E-Class
440 Great Deals out of 20,659 listings starting at $1,999
Used BMW 3 Series
963 Great Deals out of 33,201 listings starting at $1,000
Used Audi S4
24 Great Deals out of 1,542 listings starting at $3,850
Used Mercedes-Benz C-Class
584 Great Deals out of 25,555 listings starting at $1,950
Used BMW 7 Series
124 Great Deals out of 5,022 listings starting at $2,699
Used Mercedes-Benz S-Class
123 Great Deals out of 7,287 listings starting at $1,980

Used Cars For Sale

2018 Audi A6 For Sale
3,701 listings starting at $37,746
2017 Audi A6 For Sale
11 Great Deals out of 428 listings starting at $31,000
2016 Audi A6 For Sale
12 Great Deals out of 619 listings starting at $17,885
2015 Audi A6 For Sale
36 Great Deals out of 931 listings starting at $16,995
2014 Audi A6 For Sale
20 Great Deals out of 584 listings starting at $12,995

Content submitted by Users is not endorsed by CarGurus, does not express the opinions of CarGurus, and should not be considered reviewed, screened, or approved by CarGurus. Please refer to CarGurus Terms of Use.