Sounds like the balance shaft isn't timed right. It's purpose is to counteract normal engine vibration.

Answered by caradiodoc (expert)
17,277 answers provided

Can you give me some advice how I can set it right? And if it's not that, what else could it be - I'm not a mechanic, I'm just trying to collect suggestions for my mechanic

Response from martybg
1 question asked

The sprocket on the balance shaft will have a timing mark just like on the crank and cam sprockets. Many people successfully set the timing belt on the cam and crank but they think the balance shaft sprocket is just an idler pulley and it doesn't have to be timed, but even one tooth off can cause a vibration. The service manual will show where to find the timing mark on the sprocket and where to set it. I don't have a service manual for your car and I don't even know which engine you have. I prefer the manufacturer's stuff on paper but this company includes a lot more information and troubleshooting articles.

Answered by caradiodoc (expert)
17,277 answers provided