Hot take: a 2012 Corolla with 180k on it beat us on a head gasket job and I'm still mad about it
Two weeks ago a 2012 Corolla rolled in with 180k on the clock and the customer wanted a head gasket done while we had three trucks ahead of it, so my guy Marco knocked it out in a day and a half and it ran cleaner than the Silverado we fought for a week. Half the guys in my bay say jobs like that are just luck and the other half swear it's because we finally started pressure testing every cooling system before we tear it down. Have you folks been burned betting on the easy job, or is prep work the thing that actually saves you?
Buddy of mine runs a small shop out in the valley and he had the opposite happen. Took in a 2014 Civic for a timing belt, figured it was a two hour cake walk, didn't bother checking the water pump while it was apart. Three weeks later the pump let go, cracked the block, and he ended up eating most of a motor for a car he barely made money on. The kicker is he pressure tested that thing too, just never thought to spin the pump by hand. Now he makes his guys spend the extra ten minutes on the dumb stuff and he swears it's saved him thousands. Prep is cheap, comebacks are not.