Cummins Specialist · Garden City, Idaho
Cummins Diesel Repair in Boise & the Treasure Valley
Factory Cummins Insite software. Every generation from the 5.9 to the ISX. Shop service and mobile repair across the Treasure Valley.
What we do
Specialist Cummins service — shop and mobile.
Factory Cummins Diagnostics
We run Cummins Insite — the same software the dealer uses — updated annually. Root cause on the first visit, not parts-chasing.
Ram Cummins Repair
5.9L 12-valve, 5.9L 24-valve, and 6.7L Cummins in Ram 2500/3500 pickups. CP4, VP44, lift pump, injectors, turbo, EGR, and DEF.
Commercial Cummins
ISB, ISC, ISL, ISX, and X15 in Class 6–8 trucks, buses, and vocational equipment. In-frame and out-of-frame rebuilds.
Mobile Cummins Repair
Broken down in the Treasure Valley? We roll to you with factory diagnostic software on board and the parts to fix common failures on-site.
Common Cummins Problems We Fix
Cummins engines are built to last — but every platform has known failure points. Here's what we see most often across the Treasure Valley, and how we fix it right.
6.7L Cummins (2007–present)
- CP4 high pressure fuel pump failure — the most serious failure on the 6.7. Metal debris contaminates the entire fuel system. Requires complete decontamination, injector replacement, new lines, and a new pump. We do not cut corners on this repair.
- VGT turbocharger actuator failure — loss of power, excessive smoke, fault codes. We rebuild and replace VGT actuators and inspect the full turbo system.
- EGR cooler failure — coolant enters the combustion chamber. White smoke, coolant loss, overheating. We pressure test and replace EGR coolers and inspect the full cooling circuit.
- DEF system faults — contaminated DEF fluid, failed DEF injectors, and NOx sensor failures. Diagnosed accurately with factory Cummins Insite software.
- Lift pump failure — a weak lift pump accelerates CP4 wear. We install upgraded lift pump solutions on high-mileage 6.7s as a preventative measure.
5.9L Cummins (1998–2007)
- VP44 injection pump failure (24-valve) — heat and low fuel pressure from a failing lift pump kill the VP44. Hard starting, stalling, no-start when hot. We replace the pump and upgrade the lift pump to prevent recurrence.
- Lift pump failure — the stock 24-valve lift pump is notoriously weak. We replace it as preventative maintenance on any truck over 100k miles.
- Grid heater failure — causes hard cold starts in Idaho winters. We test and replace grid heaters and the associated relay.
- Injector wear — rough idle, smoke, and power loss. We test injector balance rates with factory software before recommending replacement.
ISX / X15 (Class 8 Semi Trucks)
- EGR system failures — EGR cooler and valve failures causing overheating and performance issues
- Overhead valve and injector adjustments — required at manufacturer intervals to maintain performance and prevent wear
- Fuel system diagnosis and injector replacement — factory software required for accurate ISX fuel system diagnosis
- Turbocharger and aftercooler service — turbo inspection, rebuild, and replacement plus aftercooler pressure testing
- DEF system and SCR catalyst repairs — aftertreatment system diagnosis with factory software
- Complete in-frame and out-of-frame rebuilds — full engine overhaul capability on commercial Cummins platforms
What We Do on Cummins Engines
Cummins giving you trouble?
Call us Monday through Thursday, 9AM to 5PM. No appointment needed for diagnostics. Broken down and can't make it to us? Tell us where you are.
Call 208-809-0305