So I popped my hood yesterday to put windshield washer fluid in, when I saw that a large chunk of the bushing for the engine mount above the engine was missing. So my question is, how hard is it and what steps are necessary to replace it?

 

Extremely easy, check out the IPD poly mount (even easier) and installed properly, given some time the vibration that seems to be the source of alot of complaints settles nicely

 

Is it as easy as takin the bolt out, swapping the old bushing for the new, and putting the bolt back in? How much stress is that bracket under?

 

Not much at all.

Until you put the car in gear and apply pressure to the gas pedal. Then the engine develops a fair amount of torque, either the front wheels have to rotate OR the engine has to rotate - and that upper mount is there to see to it that the wheels do the rotating(with some help from it's buddies down below).

 

Alright then I'm gonna see if I can't find that poly mount and switch it out this weekend. I had that bushing replaced about 20,000 miles ago and I feel it shoulda lasted longer than that. I guess if you want somethin done right you gotta do it yourself, right?

While I'm under there I guess I'll put new plugs in. What's a good plug for a N/A S70?

 

Yes, the poly mount is a simple as remove bolt, replace, install bolt. You do have to loosen the rear bolt on the arms from the mount back, and cut out the pressed in surround from the rubber mount, I used a hacksaw blade and it took 5 or so minutes. I would stick to Volvo plugs