Well there are few trusted people i can think of.
1-Saleem mechanic (sits right opposite madni masjid gulshan e iqbal block 5)
2-Abid mechanic (sits in the last lane before pasport office , where all the lawyers have their chambers)
3-Abdul Wahid mechanic (sits in the last workshop after the ubl sports complex mechanic and autopart market)
All of the three are good mechanics. Abid charges the most and puts in alot of time to look into the car. Saleem has a team of rookies with him so his delivery time is the best and charges reasonable . Abdul Wahid charges reasonable and can tackle sticky situations.
Now depends on which area is more suitable for you to go. Let me know and i can connect you with them.