AL1-M

I have an Audi A8 D3 and sometimes it shuts down while driving. It also happens that sometimes when I try to start the car it won't start, have changed battery so its nothing wrong with that. Usually happens after I have been driving then shut the car off and then try to start it again. If I wait about 5 minutes-2 hours it will start again. This happen very often, almost everyday.

AL1-M

To be more clear its a 4.2L V8

MP4.2+6.0

See my reply to this same kind of issue today on D4 board where I talk about it for D3's like yours: https://www.audiworld.com/forums/a8-...oblem-2915178/ As in, do a scan, but crank position sensor is a common top suspect.

AL1-M

Is it anyway I can make a scan from home without going to an Audi Dealer, they are always so expensive

MP4.2+6.0

Buy VCDS for now $200 once and set for life of car. The real McCoy. See the Ross-Tech site. You run it on your (Windows only) laptop. Or buy the phone app cheap stuff and a monthly subscription fee model with some cable and training wheel capabilities for tens of dollars in initially, but keep paying. I pay for good tools, and now only half what it was some years back basically for reasonable # of cars/licenses typical of owner (non mechanic) use.

Mister Bally

Another vote for reading the sticky post at the top of this thread. Many threads that discuss this. Only way to be certain is a diagnostic scan using the proper Ross Tech interface & software. But, based on a lot of Audi World user experiences, replacing the sensor will probably work.

As the sticky mentions, the Ross Tech interface and the Bently or equivalent service manual is mandatory if you want to repair a D3 Audi.

Here's my experience with the issue you are experiencing:
https://www.audiworld.com/forums/a8-...vable-2824444/