For owner-operators buying used, a thorough pre-purchase inspection is critical. Start by checking fair market pricing so you don’t waste time on rigs priced outside the typical range for that model, year, mileage, and manufacturer. Once you’ve narrowed your list, call to schedule the inspections.
Tip: Before you visit, run the VIN through the NHTSA VIN Decoder and the NHTSA Recall Lookup, and consider a title history check via NMVTIS. These quick checks help confirm specs, uncover open recalls, and flag potential title issues.
How to Inspect the Engine and Drivetrain – Engine Inspection Tips
Most Class 8 engines can run for greater than a million miles with proper care, so prioritize maintenance history and a clean inspection report over odometer alone. Confirm oil change intervals, aftertreatment service, and any major component replacements (turbo, injectors, clutch).
- Exhaust and Smoke: When warm, check for smoke. Blue smoke can indicate oil burning, while excessive white or black smoke can suggest fueling or aftertreatment issues.
- Belts and Hoses: Feel for cracks, glazing, fraying, or abnormal wear. Belts should have around ½ – ¾ inch of play.
- Fluids: Verify oil is at the full mark and relatively clean. Look for coolant/oil cross-contamination (milky residue).
- Aftertreatment (DPF/SCR): Ask for regen history, DPF ash loading, DEF system service, and any sensor replacements. If available, request an ECM health report and fault code history.
If you’re buying a second-hand Kenworth, ask whether the truck was connected to Kenworth TruckTech+ Remote Diagnostics (or whether you can enable it). TruckTech+ helps monitor engine and aftertreatment fault codes and streamlines service, useful for both the inspection and ongoing ownership.
What to Check on the Used Truck Exterior and Frame
Use this quick used semi-truck checklist during your walkaround:
- Frame and Crossmembers: Look for cracks, bends, sagging, fresh welds, or rust at stress points.
- Rust and Corrosion: Inspect bolts, lug nuts, headlight housings, door hinges, and panel edges.
- Tires: Confirm matching brand/size on drive axles and even wear. Look for bulges, sidewall cracking, or cupping.
- Brakes: Feel along the brake drum for grooves or roughness. Check for leaks, corrosion, and pad thickness.
- Lights and Electrical: Test all exterior lights and dash indicators.
- Leaks: Check the radiator, charge-air cooler, and all hoses for visible or audible leaks.
How to Review Maintenance Records
Good records are your best predictor of future downtime:
- Service Logs: Look for consistent PMs (oil, filters, valve adjustments) and documented aftertreatment service.
- Major Repairs: Verify dates and mileages for clutches, transmissions, turbos, EGR coolers, DPF cleanings, and NOx sensors.
- Inspection History: Review DOT inspections and any dealer multipoint inspections.
- VIN and Recalls: Match the title and VIN plate to the VIN decoded details. Confirm that open recalls are resolved or scheduled with documentation.
How to Evaluate Handling on a Test Drive
When everything looks good, drive the truck and listen:
- Note acceleration, braking, tracking, and steering play.
- Feel the suspension over bumps, and watch for pull or vibration.
- Listen for abnormal engine, driveline, or brake noises.
- Inside, ensure the seat adjusts properly and feels supportive. If it’s a sleeper, try the bunk.
When to Walk Away from a Used Truck
Save yourself the headache if you find any of the following:
- Title discrepancies, salvage/brand issues, or missing odometer disclosures on the NMVTIS report.
- Structural/frame damage or evidence of poorly repaired collisions.
- Severe blow-by, persistent smoke, or contaminated fluids.
- Aftertreatment tampering or chronic fault codes with no documented fixes.
- Unresolved safety recalls with no dealer plan in place.
Need a Professional Inspection?
If you’d prefer a certified pre-purchase inspection, contact our team of experts at Papé Kenworth. Our knowledgeable service technicians work on all makes and models and can provide a comprehensive inspection, including ECM health reports and recommendations, so you can feel confident about your purchase.
