Car wont start, randomly. 2002 Volkswagen Passat v6 2.8 GLS

If I drive my car for a while and try to start it soon after stopping, it wont start. if I leave it for several hours, it will then start fine. I have no check engine lights, and I took it to a mechanic who wasn't able to retrieve any codes so he said to take it to the VW service centre. Anybody else have experience with this?