Hi,

I recently bought a 2001.5 automatic s4 2.7t, it drove great from where I bought it to my house almost 70km. When I went to bring it to the shop the check engine light came on and turns out the 3rd cylinder had a misfire so my mechanic changed the spark plugs and the 1 coil, it passed the emission test, safety to be certified engine light stayed off. When driving normal its great everything works as it should but as soon as I try and pass or hammer the pedal it feels like its slipping and doesn't engage properly I can hear the turbos. I had him change all the coils and when he did he checked the new spark plugs and the car has been burning rich they were covered in a black sud and i changed the transmission filters and fluid. There are no engine lights on. Its automatic drives perfect when not trying to accelerate quickly what else could it be, im now at 2000$ and haven't been able to enjoy it on the road. Hopefully someone could shed some light on this problem. Thank you in advance.

Best regards Bryan

 

hmmm...sounds like your torque converter is going bad. there is a slight chance it could be a very large boost leak, in a hose, that opens up when you give it a lot of power. do a boost leak test, but it honestly sounds like your torque converter.

 

I would agree with a possible converter problem also make sure the bypass valves are holding proper pressure under higher boost

 

Thanks Dasher and Fonzo for your advice and help. I went back to my mechanic and asked him to hook up a smoke machine to the intake manifold and with in seconds smoke began to leak out, turns out at the bottom of the air intake boot for the throttle body was cracked pretty bad. Cars runs great I suggest to anyone with similar problems to try this first before spending a ton of money, in my case it could have only costed me 80.00 compared to 2000.00 I spent in process of elimination lol. I guess it could have been worst !!! Thanks again.