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Dan Sager performing diesel engine diagnostics at Sager & Sons Auto, Boise, ID
Diesel Engine Repair in Boise, ID
Diesel Runs
Different.
Power loss, hard starts, smoke, or strange boost behavior need real diagnostic work, not guesswork. We bring current scan tools and diesel-specific experience to every job, whether you already know what you need or you're starting from scratch.
Diesel Diagnostics
Current Scan Tools
3-Year / 36,000-Mile Warranty
Schedule Your Drop-Off

Diesel Engine Repair in Boise, ID

Real diagnostics for hard-working diesel trucks and vehicles

Diesel engines are built tough, but when something feels off, it usually isn't a small thing for long. Power loss, hard starts, smoke, warning lights, or strange boost behavior can point to fuel delivery issues, turbo problems, sensor faults, air leaks, or maintenance items that got pushed a little too far.

If you already know what you need, we can do it.

If you don't, start with diagnostics. We'll test it right, show you what we find, and give you a clear plan so you're not just replacing parts and hoping.

Diesel Services We Provide

From diagnostics to routine maintenance, we handle it all

Diesel diagnostics at Sager & Sons Auto Boise

Diesel Diagnostics

Current scan tools and diesel-specific knowledge to read fault codes, test live data, and trace problems to their actual cause, not just the warning light.

Diesel fuel system service at Sager & Sons Auto Boise

Fuel System Service

Injector testing, fuel filter replacement, fuel pressure diagnosis, and lift pump inspection for diesel fuel delivery concerns.

Turbo and boost system inspection at Sager & Sons Auto Boise

Turbo & Boost System

Boost leaks, turbo lag, over-boost, or underboost. We diagnose the full intake and boost system including intercooler, charge pipes, and wastegate function.

EGR and emissions system service at Sager & Sons Auto Boise

EGR & Emissions Systems

EGR valves, coolers, DPF concerns, and DEF system diagnostics for emissions-related warning lights and performance issues.

Diesel oil and filter service at Sager & Sons Auto Boise

Diesel Oil & Filter Service

Diesel engines require specific oil weights and longer-life filters. We service to factory spec at the correct interval for your application. See our Oil Change Service page for more details.

Cooling and glow plug service at Sager & Sons Auto Boise

Cooling & Glow Plug Service

Hard cold-weather starts? We test glow plugs and controllers, and inspect the cooling system for the higher thermal demands of diesel operation.

Signs Your Diesel Needs Attention

Diesel symptoms you should not ignore

Black, white, or blue smoke from exhaust
Noticeable loss of power under load
Hard starting, especially in cold weather
Check engine or DPF warning light
Excessive fuel consumption
Rough idle or shuddering
Boost gauge reading low or inconsistent
DEF system warning or regen cycle issues

Related Diesel Service Pages

Specific services with full details, pricing, and FAQs

Transmission fluid exchange Boise
Transmission Fluid Exchange
Complete fluid exchange with NAPA or OEM-spec fluid. Not just a drain-and-fill.
See Service Details
 Diesel oil change service Boise
Oil Change Service
Diesel-spec oil and filter service every 3,000 miles with a complimentary digital inspection.
See Service Details
 Diesel diagnostics electrical Boise
Diagnostics & Electrical
Check engine light, electrical faults, sensor diagnosis. We trace the cause, not just the code.
See Service Details
 Diesel exhaust repair Boise
Exhaust Repair
DPF, catalytic converter, exhaust leaks, and noise issues diagnosed and repaired correctly.
See Service Details
 Diesel fluid care Boise
Fluid Care
Coolant, brake fluid, power steering, and all fluid services to factory spec for your diesel.
See Service Details
 Diesel cooling system repair Boise
Cooling System Service
Diesel engines run hot. Thermostat, water pump, radiator, and hose service to keep temps in range.
See Service Details

Diesel FAQs

Straight answers about diesel diagnosis and repair

Do you work on diesel trucks specifically?
Yes. We service diesel trucks and diesel-powered vehicles including Ford Power Stroke, GM Duramax, and Ram Cummins applications. We bring current scan tools and diesel experience to every job.
What causes white smoke from a diesel?
White smoke on startup in cold weather is often normal as unburned fuel clears out. Persistent white smoke can indicate a coolant leak into the combustion chamber, a failing injector, or a timing issue. Don't ignore it if it doesn't clear quickly.
What does it mean when my DPF light comes on?
The Diesel Particulate Filter captures soot from the exhaust. When it fills up, the truck triggers a regen cycle to burn it off. If that cycle doesn't complete, from too many short trips or a sensor fault, you'll get a warning light. We diagnose the cause before recommending a regen or replacement.
How often does diesel engine oil need to be changed?
We recommend every 3,000 miles for most diesel trucks in everyday driving. Towing heavy loads frequently may require shorter intervals. We'll help you dial in the right schedule for how you actually use your truck.
Do you service both light-duty and heavy-duty diesel trucks?
We primarily service light-duty and medium-duty diesel trucks, your half-ton, three-quarter-ton, and one-ton pickup applications. We have experience with Power Stroke, Duramax, and Cummins platforms. Give us a call if you have questions about your specific vehicle.

Why Boise Diesel Owners Choose Sager & Sons

Diesel-Specific Diagnostics
We bring current scan tools and diesel knowledge. Not just a generic OBD reader. We test live data and trace issues to their actual cause.
Honest Repair Plans
We show you what we found, explain what it means, and give you options. No pressure, no parts-swapping guesswork.
Complimentary Digital Inspections
Photos and notes sent to your phone so you see exactly what we found and understand the recommendation before approving anything.
3-Year / 36,000-Mile Warranty
Every qualifying repair backed by our NAPA AutoCare nationwide warranty, honored at 14,000+ locations across the U.S.
Family-Owned Since 2012
Serving the Boise Bench since 2012. We treat every truck like it belongs to a neighbor, because on the Bench, it usually does.

Diesel Running Off? Let's Find Out Why.

We diagnose it right the first time, show you what we found, and fix it correctly.

📍 6126 W. Franklin St., Boise, ID  ·  📞 (208) 761-9406  ·  Mon–Fri 8am–5pm
Schedule Your Drop-Off

Auto Repair

General auto repair services for cars and light trucks, including mechanical and electrical issues.

General Auto Maintenance
Routine maintenance services to help keep your vehicle running reliably and prevent costly repairs.

Sager & Sons Auto in Boise, Idaho

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