My IS has had some engine noise for a few weeks now but I didnt think much of it at first since it was mainly at cold starts.
But it has been getting worse and worse making different noises till today there is was a MAJOR loss of power!!
It's possible you have the carbon build up as well. They would need to see if there are any stored misfire codes.
As far as the noise yes it's the pump. Your out of warranty for the pump unless you have extended coverage.