Do you work on PACCAR MX-13 and MX-11 engines?

Yes. We diagnose and repair PACCAR MX-13 and MX-11 engines in Kenworth and Peterbilt trucks, including aftertreatment, EGR, fuel system, cooling, and electrical work, on-site or in the shop.

Can you clear a derate on a PACCAR engine at my yard?

Often, yes. A derate has a cause, so the visit starts with reading fault history and aftertreatment data. If the fix is a forced regen, a sensor, a DEF issue, or a wiring fault, it is usually handled on-site. A plugged DPF that needs off-truck cleaning is arranged from there.

How fast can you get to a broken-down Kenworth or Peterbilt?

Call (918) 925-9356 any time; emergency response is available 24/7 and the ETA depends on where you are within our 120-mile service area.

Do you handle warranty work on PACCAR engines?

We are an independent repair service, not a PACCAR dealer. For in-warranty engine work, start with your dealer; we handle everything outside warranty and the rest of the truck.

PACCAR MX-11 & MX-13 Engine Repair in Tulsa

Name: Tulsa Fleet Repair
Address: 1201 N 154th E Ave, Tulsa, OK, 74116, US
Telephone: (918) 925-9356

Tulsa Fleet Repair provides expert repair and maintenance services for all types of PACCAR equipment. Gary Dale, Master Diesel Technician, works on PACCAR machinery on jobsites across the Tulsa area.

Why Choose Tulsa Fleet Repair for PACCAR Repairs?

Trusted by fleet managers, contractors, and equipment operators across the Tulsa area. Here's what sets us apart when it comes to PACCAR service:

Master Diesel Technician

We service PACCAR models to manufacturer specs.

24/7 Emergency Availability

No waiting until morning. We respond day or night for critical breakdowns or roadside support.

On-Site Mobile Service

The service truck comes fully equipped—hydraulic tools and diagnostics—directly to your jobsite.

DOT Inspections

We handle federal inspection points, documentation, and preventive measures to keep your fleet compliant.

Genuine & OEM-Grade Parts

We source high-quality parts for PACCAR equipment—no cheap knockoffs.

Heavy Equipment & Fleet

From box trucks to backhoes—we handle it all. Full support for mixed fleet operations.

PACCAR Models We Service

PACCAR MX-13 (Kenworth T680, T880, W990; Peterbilt 579, 567, 389)

PACCAR MX-11 (Kenworth T680, T880; Peterbilt 579, 567)

PACCAR PX-7 and PX-9 (Cummins-built medium-duty)

Aftertreatment systems (DOC, DPF, SCR) on PACCAR-powered trucks

Don't see your specific PACCAR model listed? No problem - we work on all PACCAR equipment.

Common PACCAR Repair Issues We Fix

EGR and aftertreatment faults

EGR valve and cooler issues, DPF soot/ash loading, and SCR efficiency faults are the most frequent causes of derates on MX engines. The fix starts with reading the fault history and the regen counters, not with parts.

Check engine or aftertreatment lamp
Frequent or failed regens
5-mph derate countdown
Loss of power under load

Fuel system and injector issues

Rough idle, hard starts, and smoke on MX engines usually trace to injectors, the fuel pump, or fuel quality. Cylinder cutout and rail-pressure tests separate the injector from the pump.

Hard start hot or cold
Rough idle or misfire
White or black smoke
Rail-pressure fault codes

Cooling system and coolant loss

EGR cooler leaks, water pump seals, and cracked coolant tubes show up as slow coolant loss with no visible drip. Pressure testing and a combustion-gas check find the source.

Coolant level drops between checks
White exhaust on startup
Overheating under load
Coolant smell in cab

Electrical and sensor faults

Chafed harnesses, corroded connectors, and failed NOx or temperature sensors trigger cascades of codes. A voltage-drop check and a scan of live sensor data usually isolate the real fault.

Multiple unrelated fault codes
Intermittent derates
Sensor circuit high/low codes
Gauge or dash warnings that come and go