Diesel Engine Repair & Diagnostics in Knoxville, Tennessee

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

28Diesel Engine Repair & Diagnostics Shops
8Open 24 Hours
4.4Average Rating
0Premium Shops

All Diesel Engine Repair & Diagnostics Shops in Knoxville

City of Knoxville Fleet Services

Knoxville, TN
(865) 215-2532
5.0★(2 reviews)
Diesel SpecialistCommercial & Fleet

Tennessee Valley Diesel

Knoxville, TN
(865) 309-5129
5.0★(3 reviews)
Diesel Engine RepairDiesel Specialist

SH Mobile Truck Repair

Knoxville, TN
24/7
(865) 315-7611
5.0★(146 reviews)
Mobile ServiceDiesel SpecialistEmergency RepairOpen 24 Hours

Clarke Heavy Duty

Knoxville, TN
(865) 689-3722
5.0★(1 reviews)
RV RepairDiesel SpecialistCommercial & Fleet

Heavyquip

Knoxville, TN
(865) 522-1335
4.7★(11 reviews)
Aftermarket PartsDiesel RepairIndependent ShopHighly Rated

Knox Speed and Diesel

Knoxville, TN
(865) 351-3941
4.7★(70 reviews)
Transmission RepairASE CertifiedBrake ServiceDiesel Specialist

Powerhouse diesel

Knoxville, TN
(865) 640-2097
4.7★(180 reviews)
Diesel Engine RepairDiesel Specialist

Power Equipment Company

Knoxville, TN
(865) 577-5563
4.6★(30 reviews)
Diesel RepairIndependent ShopHighly Rated

T & T Fleet Services

Knoxville, TN
(865) 240-4944
4.6★(34 reviews)
Diesel SpecialistCommercial & Fleet

Smoky Mountain Diesel Performance

Knoxville, TN
(865) 803-7811
4.6★(68 reviews)
Diesel Engine RepairDiesel Specialist

Stowers Machinery Corporation

Knoxville, TN
(865) 546-1414
4.5★(144 reviews)
Diesel RepairIndependent ShopHighly Rated

East Tennessee Truck & Trailer Repair

Knoxville, TN
(865) 660-2378
4.5★(122 reviews)
Mobile ServiceEmergency RepairDiesel Specialist

Tennessee Fleet Service LLC

Knoxville, TN
24/7
(865) 300-2734
4.4★(28 reviews)
Diesel SpecialistCommercial & FleetOpen 24 Hours

Tennessee Fleet Service

Knoxville, TN
24/7
(865) 300-2734
4.4★(18 reviews)
Diesel SpecialistCommercial & FleetOpen 24 Hours

AMR Fleet Services

Knoxville, TN
(865) 573-5779
4.4★(8 reviews)
Fleet MaintenanceDiesel SpecialistCommercial & Fleet

City Diesel Inc

Knoxville, TN
(865) 687-6389
4.3★(46 reviews)
DPF CleaningDiesel Specialist

Asset Fleet Service

Knoxville, TN
24/7
(865) 297-2084
4.3★(6 reviews)
Fleet MaintenanceDiesel SpecialistCommercial & FleetOpen 24 Hours

Fleet Services of Knoxville

Knoxville, TN
(865) 339-4904
4.3★(49 reviews)
Mobile ServiceFleet MaintenanceDiesel SpecialistCommercial & Fleet

TNT HEAVY TRUCK AND TRAILER REPAIR . 24hr MOBILE

Knoxville, TN
24/7
(865) 243-5773
4.3★(140 reviews)
Diesel SpecialistEmergency RepairOpen 24 HoursMobile Service

Commercial Fleet Specialist

Knoxville, TN
(865) 474-9155
4.2★(26 reviews)
Fleet Maintenance24-Hour ServiceDiesel SpecialistCommercial & Fleet

ACTS Fleet Maintenance Service

Knoxville, TN
(866) 938-5910
4.0★(46 reviews)
ASE CertifiedFleet MaintenancePreventive MaintenanceDiesel SpecialistCommercial & Fleet

Worldwide Equipment

Knoxville, TN
(865) 688-4300
4.0★(229 reviews)
Diesel Engine RepairDiesel RepairIndependent Shop

TA Truck Service

Knoxville, TN
24/7
(865) 545-0574
3.9★(965 reviews)
Preventive MaintenanceDiesel SpecialistOpen 24 Hours

TA Truck Service

Knoxville, TN
24/7
(865) 693-3934
3.9★(251 reviews)
Preventive MaintenanceDiesel SpecialistOpen 24 Hours

ACTS Fleet Maintenance Service

Knoxville, TN
(865) 938-5910
3.7★(35 reviews)
ASE CertifiedFleet MaintenancePreventive MaintenanceDiesel SpecialistCommercial & Fleet

Greater Tennessee Truck Repair

Knoxville, TN
24/7
(865) 523-6230
3.6★(30 reviews)
Diesel SpecialistOpen 24 Hours

Knox County Fleet Services Center

Knoxville, TN
(865) 215-5870
Diesel SpecialistCommercial & Fleet

Knoxville Fleet Services Department

Knoxville, TN
(865) 215-2529
Diesel SpecialistCommercial & Fleet

Diesel Engine Repair & Diagnostics FAQ — Knoxville, Tennessee

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 Knoxville 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 Knoxville 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 Tennessee?
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 Tennessee 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 Knoxville 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.