Hi all,

I'm having a strange issue that started a couple of days ago and isn't throwing any CEL codes and was hoping someone could point me in the right direction to diagnose/fix it, below are the relevant details:

2005 A4 1.8T Quattro Manual Transmission - Stock (no mods), 58k miles

I am the original owner, car has been carefully maintained w/ oil changes every 4k miles, my last major service was at 35k miles but I recently changed the cabin/engine air filter.

When I let my foot off the gas to prepare to shift from 1st to 2nd (also happens during other shifts but most noticeable from 1st to 2nd), the car feels "jerky", for lack of a better word, as if I had abruptly let my foot off the accelerator pedal (I'm not, I've been driving stick for the past 12 years). Otherwise, the car drives fine. Once in gear it accelerates/decelerates normally, turbo spools and whistles like it always did from when I bought the car.

I've read in other posts regarding jerky acceleration that maybe the throttle body is dirty, but I'm wondering if this could be something turbo related that needs adjustment (wastegate actuator rod) or perhaps another turbo related part that has gone bad (diverter valve perhaps).

I should mention that the turbo was replaced a long while back (16k miles) due to a defective housing that was slowly leaking oil. I'm wondering if the tech maybe didn't adjust or tighten something right and now after a few years it has gone out of spec.

Any help/advice would be greatly appreciated.

 

Hmm, I was thinking perhaps fuel filter is clogged. But then again, I've got fuel filter replacement on my brain today for my B6, so go figure.