Pre-Purchase Inspection

Comprehensive pre-purchase inspection of a 2007 Ram 3500 with 5.9L Cummins diesel engine to assess mechanical condition, identify potential issues, and estimate repair costs before buying.

Warnings

Tools required

Preparation

1. Park vehicle on level ground and apply parking brake
2. Place wheel chocks behind rear wheels
3. Ensure engine is cold for initial inspection, then plan for hot engine tests later
4. Gather all vehicle service records and documentation if available
5. Have owner present if possible to discuss history and known issues
6. Prepare inspection checklist and documentation method (photos, notes)

Procedure

1. 1

   Initial visual walk-around inspection
   Inspect overall vehicle condition. Check body panels for accident damage, rust, or misalignment. Examine paint condition for mismatched colors indicating repairs. Inspect windshield and glass for cracks or chips. Check all exterior lights for function and lens condition. Examine tires for even wear, tread depth (minimum 4/32 inch), age codes, and proper size. Look for fluid leaks or stains on ground under vehicle. Check bed condition for rust, damage, and proper tailgate operation.
2. 2

   Interior and electrical system inspection
   Enter vehicle and check for unusual odors (coolant, fuel, mold). Test all interior lights, gauge cluster illumination, warning lights at key-on. Verify odometer reading and check for tampering signs. Test all power windows, locks, mirrors, and seats. Check HVAC operation in all modes and temperature ranges. Inspect seats, carpet, and headliner for wear, stains, or damage. Test radio, navigation, and other accessories. Check for dashboard warning lights that remain on. Verify cruise control, turn signals, wipers, and horn function. Inspect pedal pads for wear consistent with mileage.
3. 3

   Under-hood inspection - cold engine
   Open hood and inspect engine bay for cleanliness, leaks, and modifications. Check engine oil level and condition on dipstick (should be dark but not excessively thick or contaminated). Examine oil filler cap for sludge or emulsification. Check coolant level in overflow tank and inspect color (should be pink/red HOAT per Mopar G-05 spec). Inspect all accessible hoses for cracks, bulges, or softness. Check belt condition for cracks, glazing, or fraying. Examine battery terminals for corrosion and check battery age. Look for fluid leaks around turbocharger, oil pan, valve cover, fuel filter housing, and injection pump. Check power steering fluid level and condition. Inspect air filter housing and intake system for proper installation and condition. Look for aftermarket modifications or missing emissions equipment.
4. 4

   Undercarriage inspection - front
   Raise front of vehicle with floor jack and secure on jack stands. Inspect front differential for leaks at pinion seal, axle seals, and cover. Check front axle shafts, U-joints, and axle seals for wear, play, or grease/oil leakage. Examine front suspension components including ball joints, tie rod ends, control arm bushings, and track bar for wear or damage. Check steering linkage for excessive play or damaged boots. Inspect brake components including rotors (scoring, thickness), calipers (leaks, seized pins), brake lines (rust, damage), and pad thickness. Look for fluid leaks from transmission, transfer case, and steering gear. Examine frame and crossmembers for rust, damage, or poor repair welds. Check exhaust system from manifold back for leaks, damage, or loose hangers.
5. 5

   Undercarriage inspection - rear
   Lower front and raise rear of vehicle, securing on jack stands. Inspect rear differential thoroughly for leaks at pinion seal, axle seals, and cover gasket. Check rear brake components including drums or rotors, wheel cylinders or calipers, brake lines, and lining/pad thickness. Examine rear leaf springs for broken leaves, worn bushings, or sagging. Inspect U-bolts and spring mounts for looseness or damage. Check rear shock absorbers for leaks or damage. Examine driveshafts for damaged boots, worn U-joints (check for play), and proper balance weight presence. Inspect fuel tank and lines for rust, damage, or leaks. Check exhaust system including the catalytic converter (the 5.9L uses a cat but no DPF) and muffler for damage or excessive corrosion. Examine frame and crossmember condition for rust or damage.
6. 6

   Transmission and transfer case inspection
   With vehicle still raised, check transmission fluid level and condition through the dipstick if equipped with the 48RE automatic (ATF+4 should be red/pink, not brown or burnt smelling), or the fill plug if equipped with the G56 manual. Inspect transmission pan and case for leaks, damage, or aftermarket modifications like deep pans. Check transfer case for leaks at seals and case halves. Inspect shift linkage and vacuum lines (if equipped) for proper connection. Look for signs of overheating such as discolored metal or burnt fluid. Examine transmission cooler lines for damage, rust, or leaks. Check transmission mount condition for cracks or separation.
7. 7

   Diagnostic scan and electronic systems check
   Connect a full-system scan tool capable of Chrysler/Cummins module access to the OBD-II diagnostic port under the dash. Turn ignition to ON position without starting. Check for stored diagnostic trouble codes (DTCs) in all available modules including engine, transmission, ABS, and airbag systems. Record all codes and freeze frame data. Clear codes if appropriate and note if they return immediately. Check readiness monitors status. For the 5.9L Cummins diesel, pay special attention to codes related to turbocharger, fuel injection, rail/fuel pressure, and boost pressure (note: the 5.9L Cummins does not have an EGR system). Verify communication with all control modules. Check for pending codes that haven't triggered MIL yet.
8. 8

   Cold start and initial running inspection
   Start engine and observe cold start behavior. Cummins should start readily without excessive cranking or white smoke beyond first few seconds. Listen for unusual noises including knocking, excessive valve train noise, or grinding sounds. Monitor exhaust smoke: minimal white smoke when cold is normal, but excessive black, blue, or continuous white smoke indicates problems. Check for exhaust leaks by sound. Observe idle quality and smoothness. Monitor all gauge readings including oil pressure (should rise quickly), coolant temperature, and charging system voltage (13.5-14.5V). Listen for air leaks at intake system or turbocharger. Check for vacuum leaks affecting idle. Let engine warm to operating temperature while monitoring.
9. 9

   Hot engine inspection and turbocharger check
   With engine at operating temperature, listen for turbocharger whistle or bearing noise. Check for excessive turbo shaft play by feeling intake and exhaust side for in/out movement (should be minimal). Inspect turbocharger for oil leaks at seals. Rev engine moderately and listen for smooth boost increase and decrease. Check for boost leaks by listening for hissing under acceleration. Monitor for excessive blow-by from crankcase breather tube (slight vapor normal, heavy smoke indicates ring wear). Inspect for coolant or oil leaks that only appear when hot. Check cooling fan operation and clutch engagement if equipped with mechanical fan. Verify radiator cap holds pressure and coolant doesn't overflow.
10. 10

    Road test evaluation
    Test drive vehicle on varied road conditions. Check clutch engagement and pedal feel if manual, or shift quality and timing if automatic. Verify all gears engage smoothly including reverse. Accelerate moderately and listen for transmission slipping or unusual noises. Test 4WD engagement if equipped: engage 4H and verify front axle engages (slight binding in tight turns is normal). Test 4L engagement in safe area. Monitor transmission temperature if gauge equipped. Check braking performance: pedal should be firm, brakes should apply evenly without pulling, and stopping distance should be reasonable. Listen for brake noise. Test emergency stop from 40 mph if safe. Evaluate steering response, alignment (pull or drift), and unusual vibrations. Listen for driveline clunks during acceleration/deceleration. Test cruise control operation. Monitor engine temperature, oil pressure, and all gauges during test.
11. 11

    Post-test inspection and fluid sampling
    Return vehicle to shop and allow brief cool-down. Recheck all fluid levels including engine oil, coolant, transmission, power steering, and brake fluid. If levels changed significantly during test, investigate. Consider oil analysis: pull engine oil sample for laboratory testing to check for fuel dilution, coolant contamination, wear metals, and additive depletion. Check coolant freeze protection with hydrometer or refractometer (should protect to -34°F minimum). Inspect for new leaks that appeared during operation. Check transmission fluid color and smell again when hot. Examine brake fluid color (should be clear to light amber, not dark brown). Inspect for loose components that may have been revealed during driving.
12. 12

    Diesel-specific systems evaluation
    Inspect fuel filter/water separator housing for water accumulation in bowl. Check condition of fuel filter and note service interval. Examine lift pump operation if equipped (listen for humming at key-on). Inspect injection pump for leaks or damage. Check high-pressure fuel lines for damage or leaks (do not loosen). Examine the intake grid heater system components (the 5.9L Cummins uses a grid heater, not glow plugs). Note: the 5.9L Cummins is not equipped with an EGR system, so no EGR valve, cooler, or plumbing inspection is required. Look for boost leaks at intercooler, piping, and connections. Verify wastegate operation and condition. Check for aftermarket tuners or programmers (may void warranty or cause reliability issues). Inspect fuel tank venting and check for proper fuel cap seal.
13. 13

    Final assessment and documentation
    Review all findings and compile comprehensive inspection report. Document all identified issues with severity ratings: immediate safety concerns, near-term maintenance needs, and long-term considerations. Estimate repair costs for identified issues. Photograph any significant findings. Verify VIN matches title and registration. Check for recall notices using VIN lookup. Review service history against recommended maintenance schedule to identify deferred maintenance. Calculate total estimated costs for repairs and deferred maintenance. Provide buyer with written report including recommendations for pre-purchase actions such as compression testing, detailed differential inspection, or specialist evaluation of specific concerns.

Reassembly

1. Lower vehicle from jack stands safely
2. Remove wheel chocks
3. Disconnect scan tool and close all access panels
4. Return vehicle to original condition

Verification

• Review all documented inspection points are complete
• Verify no tools or equipment left in or under vehicle
• Confirm all findings are documented with photos where applicable
• Ensure buyer understands identified issues and estimated repair costs
• Recommend professional compression testing or injection system testing if engine performance concerns noted
• Advise buyer to negotiate purchase price based on identified repairs needed

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