Anyone else experience their volvo at idle bogging up and down between 400-1000 rpms and sometimes its so rough it will actually shut off? I experience this when my car has warmed up and its becoming very frustrating

 

I ran into a similar issue with a very unexpected stall. A full PCV service (expensive hose included) got rid of the problem.

 

could be a few things - engine coolant temp sensor comes to mind as well as a stuck idle air valve (not sure if your model even has one...) as well as other vacuum and intake leak problems.

You can do a simple test for the PCV / oil trap - with the engine running, pull out the dipstick. See any smoke coming out?. Next test is to remove the oil fill cap and put a rubber (ie surgeon's ) glove over the oil fill. If it inflates while the car idles, you are not venting the crank case and should repair before you blow out your cam seals etc.