Just got second hand volvo xc70 2009 2.4 diesel 136 kw today. Everything was fine when i was testing car and wanted to buy it, just power steering didn't work. So i bought it and took home about 70 km away- car drove perfectly fine silent and had enough power. But when i stopped at home and left engine running at idle it started emitting this pulsing sound ---->video of that sound . Anyone had similar problem? How serious this could be? I already called to firm from where i bought it, and they said to make sure if this problem is serious and reproducable by tomorrow and if I really want to get money back or partial refund.

What i suspect is that something makes engine idle more ruff when its hot and dual mass flywheel starts to emit this sound. Just what it its? bad flywheel? Or badly working engine on hot idle due to some sensor or? Any experience in something similar would be really helpful. Need any info ASAP as i dont have any trustworthy volvo mechanics closer than 2h away on one way trip and have to make decision myself pretty much.