I've always used the 0w20 VAG 508/509 oil on my 2020 1.5 TSI ACT. Oil changed every 8k miles.

 

But the idle is noisy and there's a slight vibration into the cab as the car is on 103k. All normal apparently though.

 

But can I change to using 5w30 to try and quieten things down?

 

Castrol's oil checker lists a 5w30LL as an alternative to the 0w20.

Personally I'd stick with factory recommendations.

Having owed two of these engines. I'd probably change the plugs first, I had a couple fail that were changed within two years, previously. There were no fault codes present, until the misfire became very obvious & also effected the starting. Once changed, the car was back to running very smoothly again. Other issue I've noticed at higher mileage is that of coil packs breaking down, too. 

Also having my plugs replaced resolved 90% of the cold running jerkiness I was also experiencing from this engine for a while. 

The VAG tsi seems to be plug sensitive. On my 1.4tsi Superb the plugs were replaced during my last 120k miles service, I didn't think there was an issue before the service but it really improved the performance and smoothness. 

13 hours ago, Phoenixboy said:

Personally I'd stick with factory recommendations.

Having owed two of these engines. I'd probably change the plugs first, I had a couple fail that were changed within two years, previously. There were no fault codes present, until the misfire became very obvious & also effected the starting. Once changed, the car was back to running very smoothly again. Other issue I've noticed at higher mileage is that of coil packs breaking down, too. 

Also having my plugs replaced resolved 90% of the cold running jerkiness I was also experiencing from this engine for a while. 

I changed the plugs on Sunday. It's made no difference to the idle. The car drives smoothly enough it's just noisy and a wee bit lumpy at idle. Might try a coil pack next.

10 hours ago, gm73 said:

I changed the plugs on Sunday. It's made no difference to the idle. The car drives smoothly enough it's just noisy and a wee bit lumpy at idle. Might try a coil pack next.

Have you had a code reader on it? My car didn't flash up any codes until my idle became very bad mainly from a cold start, then it came up with two separate cylinder miss fires, but it seemed to run slightly lumpy before that, especially from cold, but not always. I had a Skoda extended warranty on my previous Octavia, they offered to replace 3 for free after diagnosis, I had to pay for the fourth. Also the plugs were under two years old. 

Any luck with this? Have you had the inlet valves cleaned?