About Medina Valley Diesel

Medina Valley Diesel is Castroville, Texas's dedicated diesel repair, performance, and high-end auto detailing shop. Located on US Highway 90 just west of San Antonio, we serve truck owners and fleet operators across Medina County, Bexar County, and the surrounding Texas Hill Country. Our shop was built on a simple belief: diesel trucks deserve precise, measured work from technicians who understand the machinery inside and out.

We work on the full range of light and medium-duty diesel platforms — Ford Power Stroke, Chevrolet and GMC Duramax, and Ram Cummins — as well as the commercial fleet trucks that keep local businesses moving. From hard-starting and loss of power to fuel system failures and turbocharger issues, our diagnostics pinpoint the root cause before parts are ever ordered. Routine maintenance, fluid services, and scheduled fleet care keep trucks on the road and out of the bay.

Beyond repair, we build power. Our performance and tuning services unlock reliable horsepower and torque through ECM calibration, turbo and fuel system upgrades, and matched drivetrain components. Every build is tuned to the way the truck is actually used — for work, tow, or play — so the added performance stays durable over the long haul.

We also operate a full high-end detailing service, offering Basic, Full, and Showroom detail packages plus add-ons such as ceramic coating, paint correction, and interior restoration. The same precision that drives our mechanical work carries through to every detail bay, so a truck leaves looking as engineered as it runs.

Medina Valley Diesel is locally owned and operated. Our technicians are the people who build, tune, and stand behind every job that leaves the shop. Stop by our Castroville location, call us, or book an appointment online to put your truck in the hands of a team that treats every service as a point on the timeline — measured, logged, and executed to tolerance.