I'd take the valve cover off on that side. I'd check that push rods are operating correctly (aligned), that the rockers go up and down - with valves as you manually turn engine over. Then I'd adjust the valves - that might show a broken/stretched valve stem - if one is way off.
#3 exhaust used to be the one that went first on VW since the oil cooler blocked flow to it. You want to catch a broken valve before it beats a hole in the piston and spreads shavings throughout your oil galleries and bearings.