ALWAYS take my truck to Mauricio and Peter for major problems and scheduled maintenance. Try to patronize them for oil changes whenever possible (sometimes I need to get it done quickly and hit Oil Changers)
Very conveniently located for me as I work at TEGH (5 minute walk away). Sometimes they'll finish in an hour or two, sometimes you're picking your car up at the end of the day, so I try to take it in when I'm working a day shift.
As Mariko pointed out though, they are located a short walk from Greenwood TTC station, right on the subway line.
Mechanics don't get more honest or reliable than these guys.