Diesel Pre-Purchase Inspection Before the Money Changes Hands
A diesel pre purchase inspection costs far less than the repairs a bad used truck can hide. We listen to it start, scan it on factory scan tools, drive it under load, and then call you to walk through what we found.
A washed truck with fresh oil can still hide a four-figure problem
Sellers clean trucks up before listing them, and some clear the codes. On a diesel, injectors, high-pressure pumps, turbos and head gaskets are all big bills, and a truck can idle smoothly in the driveway and still show its history on inspection.
"I was referred by a friend and they haven’t disappointed. My husband is purchasing a truck and we’ve taken them to Bodacious for the prepurchase inspection and I’m so glad we did. Instead of wasting $30k on a truck that would’ve had $8k in problems, we avoided it by having Bodacious be our first stop. Thanks for saving us money and headaches!!"Jennifer Rodriguez, Google review
What we check on a truck you are thinking about buying
The tools behind our diesel diagnostics, pointed at a truck that is not yours yet.
| System | What we look at |
|---|---|
| Scan data and codes | Stored, pending, history and permanent codes, plus readiness monitors, on factory scan tools |
| Fuel system | Rail pressure commanded versus actual, injector balance rates, lift pump, filters and water in the fuel |
| Engine and cooling | Starting, blow-by, smoke, oil condition, coolant loss, radiator, hoses and leaks |
| Turbo and air side | Boost under load, shaft play, oil in the intake, boost leaks and VGT response |
| Emissions | DPF soot load and regen data where the truck reports it, EGR, DEF and NOx sensors, and any emissions parts missing or altered |
| Transmission and driveline | Fluid condition, shift quality, converter lockup, transfer case, U-joints and axle leaks |
| Steering, suspension and brakes | Ball joints, tie rods, track bar, front-end play, pads, rotors and brake lines |
The weak points we chase on each platform
Every generation has its own short list. Pick the engine you are looking at.
6.0 Powerstroke, 2003 to 2007
Head bolts stretch and let head gaskets go, a failed EGR cooler can take out the oil cooler, and a tired FICM upsets the HEUI injectors. With head studs, a new oil cooler and the receipts to prove it, a 6.0 can be a good truck. See 6.0 Powerstroke repair.
- Oil versus coolant temperature on the scan tool
- Coolant level and degas bottle pressure
- FICM voltage, plus receipts for head stud and cooler work
The other Fords
The 7.3 is HEUI too: high-pressure engine oil fires the injectors. The 6.4 runs BorgWarner compound turbos and is known for radiator leaks, EGR coolers and fuel in the oil. The 6.7 has run a Bosch CP4.2 since 2011. See Ford Powerstroke repair.
- 7.3 high-pressure oil leaks and injectors
- 6.4 radiator, EGR cooler and oil level
- 6.7 fuel filters, water in the fuel and rail pressure
LB7 Duramax, 2001 to 2004
The first Duramax, with an IHI fixed-geometry turbo and an injector reputation. A leaking injector pushes fuel into the crankcase, so the oil level rises and smells like diesel.
- Injector balance rates at idle
- Oil level and any fuel smell in the oil
- Records of injector replacement
LLY, LBZ, LMM, LML and L5P
From the LLY on, the Duramax runs a Garrett VGT, and the LLY is known to run hot towing. The 2011 to 2016 LML uses a Bosch CP4.2 feeding two fuel rails, and a failing CP4 can send metal through the fuel system (see Duramax CP4 to CP3 conversion). The 2017 and newer L5P uses a Denso pump. More under Chevy and GMC Duramax repair.
- VGT response and boost under load
- Coolant temperature under load
- Rail pressure and fuel filters on LML trucks
5.9 Cummins, 1994 to 2007
The 1994 to 1998 12-valve runs the mechanical Bosch P7100. The 1998.5 to 2002 24-valve uses the electronic VP44, which dies early when a weak lift pump starves it. The 2003 to 2007 common-rail 5.9 moved to the CP3. On the older trucks we also check for the killer dowel pin, a known failure point.
- Lift pump pressure on VP44 trucks
- Proof the dowel pin was fixed
- Injector condition and smoke
6.7 Cummins, 2007.5 on
Ram's 6.7 arrived with a Holset variable-geometry turbo and a DPF. It ran the CP3 through 2018 and a CP4 on 2019 and 2020 trucks. DEF came to 2500 and 3500 pickups in 2013. More under Ram Cummins repair.
- Turbo response and soot buildup
- DPF, EGR and DEF data
- Fuel quality on 2019 and 2020 CP4 trucks
From the first call to the findings call
What happens between your first call and ours.
Set a time
Call with the year, engine and mileage. You or the seller brings it in. A cold start tells us more.
Start and scan
We listen to it start, then pull codes, monitors and live data.
Lift and road test
A visual check of leaks, turbo, front end, driveline and brakes, then a drive under load with the scan tool on.
The phone call
We explain what we found, what needs attention now and what can wait, so you can negotiate or walk.
What a truck's history leaves behind on a used diesel
Trucks that towed over mountain passes worked their cooling system, turbo and transmission hard. Winter adds cold starts that find weak batteries, glow plugs and grid heaters, plus road de-icer that eats brake lines and frames.
- Hitch wear and wiring that say the truck towed for a living
- Transmission fluid color and smell
- Rust on brake lines, fuel lines and the frame
Setting up an inspection on a truck you are buying
Work with the seller to get the truck here and we will try to get you in as quickly as possible. A pre-purchase inspection is one of the few things we set an appointment for. Let us know who should get the findings call. We answer the phone Monday to Friday, 8:00 AM to 6:00 PM.
What moves the cost of an inspection
No prices online. Call about the truck you found.
The platform
Some engines take more scan time and access to check.
Inspect, not repair
We do not dig into the truck on an inspection, because that would turn it into a repair. We inspect and estimate what the potential costs could be.
Modified trucks
Lift kits, added fuel systems and other changes take time to sort out.
A phone call that walks through the findings: what needs attention now and what can wait. More on our what to expect page.
Tell us what your truck is doing
Send the year, the engine and what you are seeing, and we'll get back to you as quickly as we can.
- Year, make and engine
- What it is doing, and when it started
- Any codes or recent repairs
Rather talk it through? Call (303) 808-1563
Pre-purchase questions buyers ask us
What buyers ask us before they commit to a truck.
Yes. Set the time with us, tell us who gets the call, and the seller brings the truck in for the diesel pre purchase inspection. Findings come by phone.
Clearing codes turns the light off, but it also resets the readiness monitors, and on newer trucks permanent codes stay stored until the fault is actually fixed.
Yes. Low miles can hide long idle hours, short trips that never let the DPF clean itself, or years of sitting. The scan data and the inspection show how the truck was actually used.
Then the inspection did its job. We explain what is urgent and what can wait, so you can negotiate the price or walk away.
Yes. We note that the truck is modified and anything that affects its condition. If emissions equipment has been removed or altered, we tell you, because it becomes your problem. We do not do delete work.
Found a diesel you like? Have us look at it before you buy
Call with the year, engine and mileage, or use Request Service to send the details. Or drop us a line right here from the website and we'll get back to you as quickly as we can.