I have a 2004 A4 3.0 Quattro TIP. I think that's everything. Anyway, sometimes the car just starts to decelerate. I'll have my foot on the pedal but it suddenly acts like my foot doesn't exist anymore, pedal can go all the way to the floor and nothing. Tested in cruise, still happens. Completely random. If I lift up and go back down, everything is cool. Feels like it is going into neutral but most of the time I can't see any reason for it to shift, especially when it's on cruise.

Hoping someone has an idea of what it might be. It'll be going into service for other unrelated things but I haven't had a chance to call them about the issue.

EDIT: 65k miles

 

Does it seem like the engine slow down with the car, or does it stay at a constant speed?

 

It just slows down. I called service and they seem to know what the problem is and will be taking care of it when I go in for other things next week, so hopefully all will be well soon. It is the oddest problem I've seen in a car.

 

update?

 

All better now. Brake switch was going out. Brake lights would also randomly come on even when car was parked, which brought a new perspective to the battery being dead when I had gone to pick up the car when I bought it. They thought someone had left the lights on over night, turns out it was all related. Car is like new again!