Diesel Engine Repair & Diagnostics in Great Falls, Montana

When a Power Stroke starts smoking, a Cummins loses power under load, or a Duramax throws an injector code, you want a Great Falls shop that works on diesels every day rather than once a month. The engine and diagnostic specialists here serve Great Falls and nearby Montana — 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.

15Diesel Engine Repair & Diagnostics Shops
4Open 24 Hours
4.6Average Rating
0Premium Shops

All Diesel Engine Repair & Diagnostics Shops in Great Falls

24/7
(406) 866-0113
5.0(1 reviews)
DOT InspectionsFleet MaintenanceDiesel Engine RepairRV RepairDiesel Specialist +3 more

North Star Equipment

Great Falls, MT
(406) 546-1743
4.8(16 reviews)
Diesel Engine RepairDiesel RepairIndependent ShopHighly Rated

MARS of Great Falls

Great Falls, MT
(406) 231-6766
4.8(45 reviews)
Diesel RepairIndependent ShopHighly Rated
(406) 468-5715
4.8(6 reviews)
Mobile ServiceFleet MaintenanceDiesel Specialist
(406) 868-5975
4.8(17 reviews)
Mobile ServiceDiesel Engine RepairDiesel Specialist

406 Fleet Maintenance

Great Falls, MT
24/7
(406) 438-5767
4.7(17 reviews)
Fleet MaintenanceDiesel Engine RepairRV RepairDiesel SpecialistCommercial & Fleet +1 more
(406) 452-8342
4.7(298 reviews)
Diesel SpecialistOpen 24 Hours

Tractor & Equipment Co

Great Falls, MT
(406) 761-7900
4.6(13 reviews)
Turbo RepairDiesel RepairIndependent ShopHighly Rated
(406) 452-8561
4.6(63 reviews)
Fleet MaintenanceDiesel Engine RepairRV RepairDiesel Specialist
(406) 781-0978
4.5(61 reviews)
Diesel Engine RepairDiesel Specialist
(406) 452-9551
4.5(33 reviews)
Diesel Engine RepairDiesel Specialist
(406) 866-0113
4.5(104 reviews)
Transmission RepairASE CertifiedDiesel Engine RepairDiesel Specialist
(406) 727-7153
4.4(56 reviews)
Diesel RepairIndependent Shop
24/7
(406) 720-8847
4.4(248 reviews)
Mobile ServiceFleet MaintenanceRV RepairDiesel SpecialistCommercial & Fleet +1 more

I-State Truck Centers

Great Falls, MT
(406) 454-1311
3.3(37 reviews)
Fleet MaintenanceDiesel Engine RepairEmergency RepairRV RepairWarranty Work +1 more

Diesel Engine Repair & Diagnostics FAQ — Great Falls, Montana

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 Great Falls 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 Great Falls 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 Montana?
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 Montana 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 Great Falls 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.