Reasons I don’t trust “certified mechanics”.
This car was dealer/shop maintained since it was new, by certified mechanics:
1. PO charged for a head gasket job, shop added enough stop leak to clog most of the cooling ports and 2 oil ports, HG was never changed.
2. PO charged for new radiator, shop RTV’d the leaking areas and sent it on it’s way.
3. Shop “fixed” a leaking heater hose by wrapping it in JB Weld, then taping the JB Weld to hold it while it dried.
4. Shop bypassed most vacuum lines trying to solve a running issue, which turned out to be their failed attempt at a timing belt change.
That’s just what I’ve found so far on the current daily. #1 being the reason for doing a complete driveline swap this spring.
Other things I’ve seen over the years, again, certified mechanics:
1. Replace timing belt/water pump, get cam timing off by 1 tooth, adjust distributor by 1 tooth to compensate. 1995 Mopar 3.0L (mitsu 6g72).
2. Have a vehicle for 3 months only to fail in diagnosing a fried ECU. 1990 Buick Century.
3. Cut a rim trying to remove tires, pack the cut with bead sealer, install new tires, send the owner on their way.
4. Failed to torque intake manifold, HPO sensor, and HPOP cover bolts on a Ford 6.0, leading to an almost catastrophic loss of oil while towing a car home.
5. Ordered the wrong CV axle, cut the “wrong” axle down and welded it back together to make it “fit”.
6. Owner charged for TGV replacement DS. Shop replaces passenger side with used TGV.
7. Owner charged for NEW alternator, battery, starter. Upon beginning to work on the vehicle themselves, the owner found all parts to be JY marked.
These are just some I can remember off the top of my head, some are my vehicles, some are things we’ve found working on friend’s vehicles. These are also the reasons I trust NO ONE else to touch my vehicles.