Diesel Engine Repair & Diagnostics in San Antonio, Texas

When a Power Stroke starts smoking, a Cummins loses power under load, or a Duramax throws an injector code, you want a San Antonio shop that works on diesels every day rather than once a month. The engine and diagnostic specialists here serve San Antonio and nearby Texas — with scan tools that read manufacturer codes, injector test benches, and mechanics who know which failures are common on your engine before they lift the hood.

19Diesel Engine Repair & Diagnostics Shops
8Open 24 Hours
4.5Average Rating
0Premium Shops

All Diesel Engine Repair & Diagnostics Shops in San Antonio

JTM Fleet Maintenance

San Antonio, TX
(210) 662-0019
5.0★(2 reviews)
DOT InspectionsFleet MaintenanceDiesel Engine RepairRV RepairDiesel Specialist +1 more

Commercial Truck & Trailer Repair (mobile)

San Antonio, TX
24/7
(210) 970-8577
4.9★(86 reviews)
Fleet MaintenanceDiesel Engine RepairDiesel SpecialistCommercial & FleetEmergency Repair +2 more

A-Z Complete Truck and Trailer Repair - Mobile Repair

San Antonio, TX
24/7
(346) 291-6545
4.9★(42 reviews)
Fleet MaintenancePreventive MaintenanceDiesel SpecialistEmergency RepairOpen 24 Hours +1 more

Bennett Truck Center

San Antonio, TX
24/7
(701) 621-1328
4.9★(109 reviews)
DOT InspectionsPreventive MaintenanceDiesel SpecialistOpen 24 Hours

Brady Diesel Services

San Antonio, TX
24/7
(210) 998-0647
4.9★(37 reviews)
Mobile ServiceDiesel SpecialistOpen 24 Hours

H-E-B Fleet Maintenance Shop

San Antonio, TX
4.9★(24 reviews)
Fleet MaintenanceDiesel SpecialistCommercial & Fleet

Performance Equipment Service

San Antonio, TX
(210) 452-7682
4.8★(8 reviews)
Diesel SpecialistDiesel RepairIndependent ShopHighly Rated

Emergency Truck & Trailer Repair

San Antonio, TX
24/7
(210) 508-9212
4.7★(72 reviews)
Hydraulic RepairRV RepairDiesel SpecialistEmergency RepairOpen 24 Hours

Villanueva & Sons Fleet Service

San Antonio, TX
24/7
(210) 861-5013
4.7★(15 reviews)
Diesel Engine RepairDiesel SpecialistCommercial & FleetOpen 24 Hours

D & S Garage and Diesel Service

San Antonio, TX
(210) 340-8054
4.7★(265 reviews)
Brake ServiceDiesel Specialist

Austin Fleet Services - SAN

San Antonio, TX
(210) 750-6543
4.6★(54 reviews)
Fleet MaintenanceBus RepairDiesel Engine RepairDOT InspectionsMobile Service +3 more

Texas Diesel Injection

San Antonio, TX
(210) 646-8299
4.6★(114 reviews)
Diesel Engine RepairDiesel Specialist

I.M.J. Truck Repair

San Antonio, TX
(210) 661-4605
4.5★(50 reviews)
RV RepairDiesel Specialist

FleetPride Service Center

San Antonio, TX
(210) 740-0888
4.4★(55 reviews)
DOT InspectionsMobile ServiceEngine DiagnosticsDiesel SpecialistCommercial & Fleet

Duffin Diesel

San Antonio, TX
(210) 341-8183
4.4★(67 reviews)
Diesel Engine RepairDiesel Specialist

TA Truck Service

San Antonio, TX
24/7
(210) 666-0927
4.1★(273 reviews)
Preventive MaintenanceDiesel SpecialistOpen 24 Hours

Diesel Engine and Injection Sales & Services

San Antonio, TX
(210) 648-4500
4.0★(29 reviews)
Mobile ServiceDiesel Engine RepairPreventive MaintenanceDPF CleaningDiesel Specialist

TA Truck Service

San Antonio, TX
24/7
(210) 310-0238
3.6★(38 reviews)
RV RepairPreventive MaintenanceDiesel SpecialistOpen 24 Hours

Texas Truck Shop

San Antonio, TX
(210) 661-2466
3.4★(70 reviews)
Diesel Engine RepairDiesel Specialist

Diesel Engine Repair & Diagnostics FAQ — San Antonio, Texas

My check-engine light is on but the truck runs fine — do I really need a diesel diagnostic?
Yes, and sooner rather than later. On a modern diesel the light often means an emissions, sensor, or fuel-pressure fault that has not become a driveability problem yet. A San Antonio diesel shop can pull the code, read live data, and tell you whether it is a $40 sensor or the early sign of a failing injector. Diagnostic time is normally billed as a flat fee or one hour of labor.
How do I know a San Antonio shop is a real diesel specialist and not a general garage that "also does diesel"?
Ask what scan tool they use for your engine, whether they have replaced injectors on your platform this month, and how they test fuel pressure and contribution. Specialists answer in specifics — Ford IDS, Cummins INSITE, GM GDS2, balance rates, HPOP pressure. Their reviews will mention specific repairs, not just oil changes.
What are the most common engine repairs on diesel pickups in Texas?
Across the state the same handful of jobs come up: injector replacement, turbo actuator and vane failures, high-pressure fuel pump or CP4 failures, EGR cooler leaks, head gasket and stud jobs on 6.0 Power Strokes, and fuel contamination from bad diesel or water in the tank. Cold Texas mornings also expose weak glow plugs and batteries.
How long does a typical diesel engine repair take?
A diagnostic and sensor swap can be same-day. A full injector set is usually one to three days depending on parts. Turbo replacement runs one to two days. Head gaskets and in-frame rebuilds are measured in weeks, not days, because of machine-shop time — ask your San Antonio shop for a realistic window and whether they can source parts before you drop the truck off.
Are aftermarket parts fine for diesel engine repairs, or should I insist on OEM?
For injectors, high-pressure pumps, and turbos, most experienced mechanics steer you to OEM or a reputable remanufacturer with a real warranty — cheap injectors are the top cause of comebacks. Filters, sensors, gaskets, and hardware from a quality aftermarket brand are generally fine. Get the part brand and warranty terms in writing on the estimate.