Before you hand over thousands for a used car, let a certified mobile mechanic inspect it at the seller's location. We catch hidden fault codes, frame damage, flood signs, and odometer fraud — then give you a full written report so you can negotiate or walk away with confidence.
A thorough, mobile inspection at the seller's location — here's everything we check.
We scan every control module in the vehicle: engine (PCM), transmission (TCM), ABS, SRS/airbag, body control (BCM), HVAC, steering, and more. We retrieve all stored, pending, and historically cleared fault codes — including codes the seller may have cleared days before listing the car.
Visual and mechanical inspection of the engine bay: belt and hose condition, gasket integrity, oil condition and level, coolant color and pH, signs of overheating or prior leaks, transmission fluid color and smell, CV axle boot condition, and driveshaft integrity. We look for the signs a quick test drive can't reveal.
Brake pad thickness and wear pattern, rotor condition and thickness measurement, caliper operation, brake line integrity, brake fluid moisture content (high moisture = dangerous in heavy braking), ABS module fault scan, traction control status, and emergency/parking brake function.
We evaluate every major fluid: engine oil (color, viscosity, metal particle signs), coolant (concentration, silicate depletion, combustion gas test), transmission fluid (color, burn odor, debris), brake fluid (moisture percentage via test strip), and power steering fluid condition. Fluid condition tells the story of how the car was maintained.
Battery cold cranking amp (CCA) load test vs. rated capacity, alternator output voltage under load, parasitic draw assessment, key electrical system scan via OBD-II, fuse box physical inspection, and ground strap integrity. Electrical problems on a used car can cost thousands — we find them before you buy.
Visual inspection of all accessible frame rails, unibody seams, and weld quality. We look for straightening tool marks, crumple zone deformation, panel gap inconsistencies indicating prior collision repair, paint overspray on weatherstripping and undercarriage components, and subframe mounting point condition.
We check for odometer tampering using multiple independent methods: OBD-II module mileage cross-reference (PCM, TCM, ABS, BCM all store mileage independently), instrument cluster inspection for replacement signs, wear pattern analysis on pedals/steering wheel/seat bolts/door handles, and verification against available history records. A rolled odometer won't fool all of these checks simultaneously.
After the inspection you receive a clear written summary: every issue found, a severity rating (critical / moderate / minor), estimated repair cost range, and our honest recommendation — buy, negotiate the price down, or walk away. No pressure. Just the facts.
A basic code reader shows you the surface. Our scan goes deeper.
Sellers routinely clear fault codes using a cheap OBD-II reader before listing a car. The warning light goes out. The car looks clean. But our scan examines freeze-frame data — the snapshot of sensor conditions at the moment a code was triggered. Even after a clear, abnormal fuel trim values, misfire counters, and short-term oxygen sensor corrections can expose underlying issues that haven't yet re-triggered a code. We also check readiness monitor status: if multiple monitors are incomplete, the car was recently driven specifically to reset monitors after a code clear — a major red flag.
Beyond stored and pending codes, we analyze real-time sensor data while the engine runs. We watch O2 sensor switching frequency (sluggish sensors indicate aging and upcoming failure), MAF sensor output vs. expected values for the engine size (high or low values indicate contamination or vacuum leaks), coolant temperature curve (slow warm-up indicates a stuck thermostat), idle stability and MAP sensor vacuum readings (rough idle or vacuum leaks that haven't yet triggered codes), and throttle body response. Live data reveals problems invisible to a code scan.
We read transmission control module data including shift adaptation tables, individual shift solenoid activation patterns, torque converter clutch engagement quality, and transmission fluid temperature. A transmission that has 'learned' to compensate for a failing solenoid or worn clutch pack will show elevated adaptive shift values — its way of covering up a problem before it escalates to a stored code. We find this data before it becomes a $3,000–$5,000 repair.
The SRS (Supplemental Restraint System) module stores airbag deployment history in non-volatile memory that survives battery disconnects and code clears. We read the SRS module directly — not just the dashboard light. A car can have a cleared airbag warning light and still have an SRS module recording two deployed front airbags and two fired seatbelt pretensioners. Airbag replacement costs $1,500–$6,000+ depending on what deployed. We verify the complete airbag and seatbelt system status before you commit.
An incomplete EVAP (evaporative emissions) readiness monitor is one of the clearest signs a car recently had fault codes cleared and hasn't been driven through a full drive cycle to reset the monitors. Sellers who clear codes before a sale inadvertently leave this fingerprint. We check the status of all OBD-II readiness monitors — EVAP, oxygen sensor, catalyst, EGR, and more — to give you a complete picture of the vehicle's diagnostic history and recent activity.
Digital odometers can be rolled back. We use multiple independent checks to verify the mileage is real.
Modern digital odometers can be rolled back using commercially available programming tools — the same tools used by dealers and mechanics for legitimate cluster replacements. Analog odometers are physically reset by removing and rewinding the gear mechanism. Both methods leave detectable traces. Our inspection uses five independent verification methods so that rolling back the odometer on just one system doesn't fool our full inspection.
Modern vehicles store mileage in multiple independent control modules: the engine control module (PCM/ECM), transmission control module (TCM), ABS module, and body control module (BCM) each maintain their own mileage records. We read and compare these values against each other. A rolled odometer cluster will show a new mileage, but the PCM, TCM, ABS module, and BCM will all still agree with each other — and disagree with the cluster. This is one of our most reliable fraud indicators.
Physical wear on a vehicle tells the truth regardless of what the odometer says. We inspect: pedal rubber wear (brake, gas, clutch — worn through rubber on a 'low mileage' car is a red flag), steering wheel leather or grip wear, seat bolts for wrench scratch marks indicating removal and cluster swap, door handle and armrest wear depth, shift knob condition, and sun visor wear. A car with 40,000 miles showing wear consistent with 120,000+ miles has a problem.
We inspect the instrument cluster itself for signs of replacement: mismatched plastic sheen vs. the surrounding dash, different screw torque patterns than factory specification, pixel degradation inconsistent with claimed mileage on digital displays, and airbag warning light behavior differences that suggest a replacement cluster wasn't properly initialized to the vehicle's VIN. A replaced cluster can legally show any mileage — even lower than the car's actual mileage.
We compare the condition of wear items against what's normal for the stated mileage. Brake rotor minimum thickness cross-referenced with claimed miles since last service. Serpentine belt cracking and glazing versus claimed mileage. Tire tread depth versus age and claimed use. Coolant and transmission fluid condition versus service intervals. Severe premature wear in multiple systems simultaneously is a strong indicator that the vehicle has more miles than the cluster shows.
We cross-reference the vehicle's VIN against available history records during our inspection. If a vehicle's last recorded mileage at a prior inspection was higher than today's odometer reading — that's rollback. We also check for title history states known for lax odometer disclosure requirements, which are a common source of rolled-back vehicles in the DFW used car market.
Suspect odometer fraud on a car you're considering? We can verify it before you buy.
📞 Call (972) 382-9151Every pre-purchase inspection we perform has the potential to save our clients thousands of dollars. Here are specific examples of what we've found during inspections in the DFW area:
Transmission slipping caught via live TCM data showing elevated torque converter slip RPM — the seller had cleared the P0740 code. The buyer saved approximately $4,000 by walking away from the deal.
Blown head gasket on a "runs great" engine — our combustion gas test came back positive in the coolant reservoir. There was no stored code because the seller had been topping off the coolant to mask the symptom.
Airbag light cleared after an accident — the SRS module recorded both front airbags deployed and both front seatbelt pretensioners fired. The estimated repair cost to properly restore the safety systems was approximately $5,500.
Flood car sold as hail damage — the BCM showed simultaneous HVAC, door module, power window, and instrument cluster faults. This is a classic multi-system flood signature that a simple code clear can't fully hide.
Frame damage behind fresh undercoating — structural repair welds were visible on the driver's side frame rail, covered with fresh rustproofing spray to conceal the repairs.
Rolled odometer — the instrument cluster showed 52,000 miles, but the PCM showed 178,000 and the BCM showed 181,000 miles. That's a 130,000-mile discrepancy the seller hoped no one would check.
Common questions about our DFW mobile pre-purchase car inspections.
Pricing for our DFW pre-purchase inspection varies based on vehicle type and your location within the DFW Metroplex. Call us at (972) 382-9151 for a specific quote — we'll give you a price before you schedule. Our inspection fee is almost always a fraction of what a hidden mechanical or structural issue would cost to repair, and many clients use our written report to negotiate hundreds or thousands off the purchase price. We also offer a peace-of-mind guarantee: if we find something that changes the deal, our fee has already paid for itself.
Yes — that's exactly how our pre-purchase inspections work. We come to wherever the vehicle is: a private seller's home, a dealership lot, or a private sale location anywhere in the DFW Metroplex including Frisco, Plano, McKinney, Celina, Prosper, Allen, Richardson, Garland, Lewisville, and Dallas. You don't need to have the car delivered or transported. We bring our professional-grade diagnostic tools to the car.
A seller who refuses a pre-purchase inspection is giving you important information about the car. Reputable private sellers and dealerships routinely allow independent inspections — it's standard practice and any refusal is a significant red flag. We recommend walking away from any vehicle purchase where the seller won't allow an independent inspection. The few sellers who refuse almost always have something they don't want you to know.
Yes. We use five independent methods to verify odometer accuracy: OBD-II module mileage cross-reference (comparing the PCM, TCM, ABS module, and BCM — each stores mileage independently), instrument cluster inspection for replacement evidence, wear pattern analysis on pedals, steering wheel, and seat bolts, component condition vs. stated mileage, and history record verification. A rolled odometer won't match across all five checks simultaneously — the discrepancy will surface.
A complete pre-purchase inspection typically takes 45 to 90 minutes depending on the vehicle type, age, and any issues discovered. More complex vehicles, lifted trucks, or vehicles with known issues to investigate more closely may take longer. We'll give you a time estimate when you call. We stay until the inspection is complete — we won't rush through it to make another appointment.
You receive a written summary of all findings, organized by severity: critical issues (things that affect safety or that would be expensive to repair), moderate issues (items that need attention but aren't urgent), and minor items (maintenance items or cosmetic concerns). Each finding includes an estimated repair cost range. We'll also walk you through the report verbally and answer any questions you have about what we found.
Yes. Private seller locations are where most of our pre-purchase inspections take place. We come to the home, driveway, or meeting location where the car is parked. Private sales carry higher risk than dealer purchases because there's less accountability — no lemon law protection, no ability to return the car. This makes an independent pre-purchase inspection even more valuable when buying from a private seller.
Yes. While dealerships typically provide more accountability than private sellers, used car inventory at dealerships can still have hidden problems. 'As-is' used cars at dealerships often come without warranty, and dealer inspections aren't always comprehensive or fully disclosed. Our independent inspection gives you a second opinion from a mechanic who has no financial interest in the sale going through.
Absolutely. Many serious mechanical problems don't trigger fault codes, especially early in their development. A head gasket that's beginning to fail may not show an engine code but will show elevated coolant temperature, combustion gases in the coolant, and abnormal live data patterns. Frame damage doesn't show in any fault code. Fluid conditions, brake wear, and suspension integrity are all physical inspections that our scan tools complement but don't replace. The diagnostic scan is one component of a multi-point inspection.
Yes, and many clients do exactly that. If we find a brake job needed ($400), a faulty oxygen sensor ($250), and signs that the battery is near end of life ($180), that's $830 in documented near-term repair costs you can present to the seller. Some sellers will simply fix the issues; others will reduce the price. Either way, our written report with repair cost estimates gives you leverage. Some clients have negotiated $1,500–$3,000 off the asking price using our findings.
Don't buy that car until you know exactly what you're getting.
Specializing in advanced OBD2 vehicle diagnostics, European smart key replication (BMW, Mercedes, Audi, VW), module programming (ECM, BCM), and comprehensive pre-purchase inspections. We also offer expert Copart and IAAI auction inspections, evaluating auction vehicles before you bid. Our services cover complete battery load testing, alternator diagnostics, electrical troubleshooting, and check engine light (CEL) decoding.
Proudly serving the Dallas-Fort Worth (DFW) Metroplex, including Frisco, Plano, McKinney, Celina, Prosper, The Colony, Dallas, Lewisville, and Allen, TX.