Hi everyone
Sorry to return to the topic of 1.2 TSi turbos/wastegates, but my problem isn't quite like others (e.g. here and here) and it has recently left me with limited power in difficult situations (busy uphill dual carriageways).
Between 1.5k and 3k revs I get a rapid stuttering (per 5x per second). It can be controlled by easing off on the accelerator and changing down (usually 2 gears). If I ignore it, I get a ping and the EPC, ECL and ESP (Electronic Stability Programme) lights come on amber. All 3 lights always come on together. There is some loss of power, and I need to stop and turn off the ignition to clear the lights. There are no stored or pending fault codes on my OBDII reader.
Thinking it must be to do with the turbo pressure building up, then the wastegate opening, then closing and building up again in a rapid cycle, I removed the actuator to see if anything was jamming, but the actuator and wastegate seem to move freely. I removed the shim that was fitted in the recall, and this improves the situation. I recently tried putting it back, but this made it worse. I also changed the actuator with a reclaimed unit from a German dealer. I know that you can't just change them without recalibrating, but I did anyway and it made no difference. The problem appeared suddenly about 5 years ago and I've lived with it since then. Previously I had no problems (or turbo lag), both before and after the shim was fitted.
I doubt it actually needs a new turbo and figure that it is just a sensor or calibration. Could an independent turbo specialist do this? Anyone have experience of Total Turbo Solutions? Or am I barking up the wrong tree? Would you try other things first?
Any advice gratefully appreciated! If I get it fixed I will have a spare actuator (I forget which length) available.