I have a 2003 Audi A6 3.0, about 5 days ago my car started to hesitate randomly in the 1,000 to 2,000 rpm range. It wasn’t frequent at all, so I didn’t think much of it, the next day when I drove it to work, it became more and more frequent and throughout the whole rev range. It feels like a misfire but I do not have a flashing check engine light, and it’s not overheating, but it was smoking a light white smoke through my defrost vent randomly. When I opened the hood I saw a very very small crack that would create drops of water which would then land on two sensors at the end of the driver side valve cover. There right behind the last coil pack on that bank, if those sensors became corroded would that throw off the operation of that engine? I haven’t driven the car since the issue became worse (4 days ago).

 

So when you're stopped at a light and you get on the gas it doesn't respond to your input (Foot on the go pedal) but then suddenly jumps forward when it finally catches?

This is a classic symptom of a failing torque converter if that is the case.

And I don't really follow with the whole "crack" thing. Where was the crack? When you say "water" do you mean coolant? I'm thinking you're referring to a hose or the expansion tank leaking on your EGR (kombi) valve, but if you can provide more information, I maybe able to help you out a little better.

 

Yea sorry i meant that, i use 50/50, but to answer the other question it does respond to gas and doesn't jump forward. My understanding if a torque converter was failing it would slip as well while being in gear? What makes me think that this is a engine issue is that when at a stop and idling the whole car shakes. How i can tell its leaking on the two sensors is following a calcium trail.

 

Resolved the issue, once I cleared the ecu and cleaned the mass air flow sensor, I got a flashing check engine light. Sure enough when I got the codes read, cylinder 1 had a misfire, replaced the coil pack and the car is back to normal.