Accessing the timing chain, water pump, and VVT actuators require removal of the timing chain cover which there seems to be some debate on if the engine needs to be removed to accomplish this. The Mazda service manual says to remove it, but I think that is just because it is a tight fit and there is not a lot of room to work with. Most people would not want to remove the engine just to replace one of these components and luckily we do not have to. I just completed replacement of all of these parts in my 2011 Mazda CX-9 and the engine did not need to be removed. I did have to raise and lower the engine as needed to access bolts and remove the timing chain cover, but that is not unusual when replacing a timing chain on most front-wheel drive vehicles. I'm working on the DIY for this, which may take me a week or two, but wanted to start up the thread for this.