It's not liking this low mileage usage. Needs taking for a proper run regularly. When you do this, try holding it in 3rd if you can to make sure the engine sees some revs. Another possibility is that the pump timing has slipped out. This was a bugbear of the old belt cam 2.5. That would mean replacing the timing belt and resetting the valve and pump timing, which is a job nobody likes trying to do.