Engine Diagnostic in the area around San Marco, Jacksonville, FL averages $112.00, with prices ranging from $75.00 to $150.00 based on 11 verified prices from 11 nearby shops.
Showing nearby shops within 25 mi of San Marco · June 2026
Engine Diagnostic prices in San Marco, Jacksonville, FL range from $75.00 to $150.00 at local auto repair shops, based on verified pricing data gathered from 11 shops across the area. An engine diagnostic (also called a 'check-engine diagnosis' or OBD-II scan) reads fault codes from the vehicle's onboard diagnostic system, which monitors hundreds of engine, transmission, and emissions parameters. Prices for this service in San Marco vary by vehicle make and model, the grade of parts and fluids used, and whether you book with an independent shop, a franchise chain, or a dealership. Independent and chain repair shops in San Marco typically charge 20 to 40 percent less than dealerships for this service; dealerships may justify the premium for warranty-covered work or brand-specific diagnostics. All prices listed on this page were verified directly from shop websites or user-submitted receipts, and each carries a Last Verified date. For details on how PriceMyFix verifies prices, visit pricemyfix.com/about/methodology.
| Shop | Type | Price | Details | Verified | Distance | Actions |
|---|---|---|---|---|---|---|
| RC Mobile Mechanic8365 Dix Ellis Trail | Independent | $75.00Below avg | Last verified 40 days agoby PriceMyFix | 8.2 mi | View Shop | |
| Miller's Automotive2175 Kingsley Avenue | Independent | $75.00Below avg | Last verified 40 days agoby PriceMyFix | 11.4 mi | View Shop | |
| Tire Kingdom375 Blanding Boulevard | Independent | $129.99Above avg | Last verified 40 days agoby PriceMyFix | 11.6 mi | View Shop | |
| McDermott Motorsports Mobile MechanicsHodges Boulevard | Independent | $150.00Above avg | Diagnose and concerns/issues with vehicle. Identify and repairs, parts needed. Includes same day quote for repairs | Verified 3 weeks agoby PriceMyFix | 11.6 mi | View Shop |
| First Choice Car Care463670 Florida 200 | Independent | $129.99Above avg | Last verified 32 days agoby PriceMyFix | 22.5 mi | View Shop | |
| Amelia Repair LLC2112 Egret Lane | Independent | $75.00Below avg | Last verified 32 days agoby PriceMyFix | 26.2 mi | View Shop | |
| Steve Johnson Automotive1505 South 14th Street | Independent | $129.99Above avg | Last verified 40 days agoby PriceMyFix | 26.2 mi | View Shop | |
| WRENCHMAN AUTOMOTIVE LLC23 Pacific Street | Independent | $89.99Below avg | Last verified 40 days agoby PriceMyFix | 33.7 mi | View Shop | |
| Atlantic Automotive155 A1A Beach Boulevard | Independent | $129.99Above avg | Last verified 32 days agoby PriceMyFix | 38.4 mi | View Shop |
The average engine diagnostic in San Marco, Jacksonville, FL costs $109.44 across 9 shops. The cheapest verified price is $75.00 at RC Mobile Mechanic.
Trucks and SUVs with higher oil capacity may cost more. Check individual shop listings for vehicle-specific pricing.
An engine diagnostic (also called a 'check-engine diagnosis' or OBD-II scan) reads fault codes from the vehicle's onboard diagnostic system, which monitors hundreds of engine, transmission, and emissions parameters. When a sensor reads outside its expected range, the ECU logs a fault code (P0XXX format) and illuminates the check-engine light. A diagnostic reads these codes but does not automatically identify the repair — it narrows down the system affected. A thorough diagnosis also includes live data analysis (sensor readings in real time), symptom correlation, and in some cases additional tests (compression test, smoke test, fuel pressure test) to confirm the root cause.
Immediately when: (1) the check-engine light is solid (not flashing) — this indicates a non-critical fault that should be addressed soon, (2) the check-engine light flashes — this is an active misfire causing catalyst damage; stop driving immediately if it's flashing rapidly, (3) you notice a specific drivability symptom (rough idle, hesitation, poor MPG, stalling) even without the light, as some sensor failures don't trigger the light until they worsen, (4) before buying a used vehicle — a scan at a shop or self-scan reveals hidden fault codes the seller may not have disclosed.
It depends entirely on what's causing the light. Most solid check-engine lights are minor — an EVAP leak (loose gas cap), an O2 sensor reading slightly off, or a knock sensor fault — conditions that won't leave you stranded or cause immediate damage. A flashing check-engine light is different: that's an active misfire that sends unburned fuel into the catalytic converter, which overheats and fails. Cat replacement at $1,000–$2,500 is the near-term consequence; delayed, the catalyst material melts and can be ingested into the engine. Never drive more than a few miles with a flashing light.
Diagnostic pricing and recommendations vary more than almost any other service: (1) most shops charge $75–$120 for diagnosis; some waive or credit it if you authorize the repair — ask upfront, (2) reading a code yourself with a $25 Bluetooth OBD adapter (Torque Pro, Car Scanner) tells you the code; it does not tell you the root cause or whether the repair a shop recommends actually addresses it, (3) P0420 (catalyst efficiency below threshold) is one of the most frequently misdiagnosed codes — shops often recommend a $1,500 catalyst when the actual fault is a failing O2 sensor ($150–$300), (4) any shop that gives a repair quote based solely on the code without additional testing (live sensor data, component tests) for codes that can have multiple causes deserves a second opinion.
All prices verified from public sources and user submissions. Learn about our verification methodology.
