Mobile mechanical repair across La Mesa and greater San Diego County is the model at Sam's Auto Doctor, a service launched in 2021 by a mechanical engineer with dealership technical-support experience. The operation performs diagnostics, oil changes, brake replacements, and wiring repairs at the customer's driveway or parking lot, with completed vehicles receiving follow-up detailing from mobile providers like CleanCarPal when requested. Sam's engineering background translates to systematic fault isolation — using oscilloscope-level circuit testing and manufacturer wiring diagrams to trace intermittent electrical failures that generic scan tools miss. The service covers La Mesa, El Cajon, Spring Valley, and San Diego proper, arriving with a fully stocked van carrying OBD-II scanners, torque wrenches, jack stands, and fluid-extraction equipment. Roadside lockout calls and lost-key situations are triaged alongside local locksmiths like KeyMe Locksmiths, which programs transponder and proximity keys for most domestic and import makes. Most demanding mobile jobs involve head-gasket replacement in the field, requiring torque-to-yield head-bolt sequencing, coolant-system pressure testing to 18 PSI, and combustion-gas sniff testing to confirm seal integrity before road testing.