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Hello,

Just wanted to know if anyone is familiar with two issues I’m having that the VW dealer cannot find even after having the car for 2 days, but happened for me again as usual as soon as I drove the car away. Due to covid, they won’t sit in the car with me so I can’t demonstrate it to them.

I’ve noticed the issues since getting the car back from MOT, major service, “engine flush” and air con regas. The car is a petrol 1.2tsi 2016 plate, and a manual gearbox.

Issue 1: when the car is first started and not yet at operating temperature, I’m now struggling to drive smoothly at low revs. Eg. Driving around a car park, or even driving calmly down a road. The car seems to lurch a bit. Similar to the start of when someone “kangaroos” a car if at too low revs. Seems to be doing it even in 3rd gear and at around 1500-1700 revs. I didn’t notice this behaviour before work was carried out, and the car isn’t telling me to shift down a gear, which it tends to do if I drop down to 1000rpm or less. The problem isn’t there when the engine is warm, and if you drive it harder when cold.

Issue 2

I’m not sure if this is when car is just cold, warm or both. But when looking to move off from stationary there is a noise that sounds like a repetitive mechanical noise, or maybe a knocking, or maybe it’s both. It happens in 1st or reverse, and sometimes neutral (as I’ve rev’d a little to test it). First time I noticed it was moving off out of a space in a car park. I also experienced a fairly violent worrying shaking from side to side when moving off from a junction, but the shaking to that degree has not happened again.

Ive worked out if I Rev to between 1700 and 1900 while balancing the clutch I experience that noise pretty much every time. Sent the attached videos of the noise to VW and they said they couldn’t hear anything that sounded abnormal.

Links to videos of the noise in issue 2:

https://youtube.com/shorts/kBXwtKiDiac?feature=share

https://youtube.com/shorts/u-qlrT0DFNQ?feature=share

The first issue does not seem right for this engine, my wife's August 2015 1.2TSI 110PS 6MT behaves perfectly from cold/very cold start up to normal operating temperature - and always had done.
Your car sounds as though either the engine coolant temperature sensor is giving out duff info so upsetting the "auto-choke" which is in reality injection firing period, or VW Group have rolled out an engine ECU update and that has messed up the cold running.

Now, if you had something like VCDS you could keep an eye out for S/W changes during "times in VW workshop", and that would have given you something solid to work/argue with them about, I am assuming that it was a VW workshop that serviced your Polo, if not then forget the "S/W update" as being a possibility.

Engine flush being essential to keep their revenues up.

The second issue, if you think that is is engine related, is probably just the turbo boost control stuff operating, they do tend to make the engine sound like the exhaust has failed when increasing the demand at low revs and especially when not fully heated up.