[Nomad1]

I've asked others about my 2003 GTI, 1.8T, automatic, about it's strange behavior.The cars runs very well most of the time, except starting off in low gear.... it suddenly make this "loud sucking" sound from the air intake, then hesitates a bit , then take off like a bat out of hell.You never know when it's going to happen. It occurs less often when using the manual mode/shift , and occurs more often when cold.
I've had the tranny look at , good fluid, everythings was "O.K."
I've cleaned the MAF sensor, seafoamed the injectors, new air filter, changed the oil/fitler, changed the plugs & coils.
I do have a check engine code/light for O2 sensor... front or back ?
The car pulls and runs well, I just can't figure out why it acts out like this, when pulling away from a stop light.
Any ideas.....? Thanks

 

[_FUBAR_]

Sounds normal. Could just be the turbo you are hearing. They can be noisier in the winter do to the air being more dense. It really could be anything though. Could be the secondary air pump just making noise. Could be the transmission too.

 

[Shameless]

Transmission is just shifting into first slowly or requires some power to make the transition.
Colder the fluid is more thick.

the mk4 triptronic has a lot of kinks, I wouldn't try to take off like a bat out of hell in it ever. It's just not a strong trans.
Ask me how i know.