P0316 on Ford: How to Diagnose & Fix
Misfire Detected on Startup (First 1000 Revolutions)
3 Ford models · 3 documented issues · 1 critical · $500-$8,000 repair
P0316 on Ford by model: symptoms, diagnosis and fix
A subset of 2.3L Bronco owners report unexplained coolant loss, startup misfires, white exhaust smoke, and rough running traced to coolant entering one or more cylinders. Similar to other Ford 2.3L applications, the root cause is often linked to cylinder head casting issues or sealing failure in the head-gasket area. If ignored, the condition can lead to catalytic converter damage or engine replacement.
Common Symptoms
- Coolant loss with no visible external leak
- Cold-start misfire
- White exhaust smoke
- Rough idle
- Sweet smell from exhaust
How to Fix
Technicians typically pressure-test the cooling system, inspect spark plugs for steam cleaning, and borescope cylinders for coolant intrusion. Repairs range from head gasket and cylinder head replacement to complete long-block replacement depending on severity. Monitoring coolant level and addressing misfires early can prevent more extensive damage.
Sources for this issue (1)
The 3.5L EcoBoost in the Flex (the same engine used in the Taurus SHO; in the Flex it came on EcoBoost/Limited AWD models) is direct-injected only, so no fuel ever washes across the back of the intake valves. Oil vapor pulled through the PCV system and exhaust residue from valve overlap bake onto the valve stems and seats. As the deposits thicken they disrupt the low-velocity airflow at idle first, producing a rough or lopey cold idle, then progress to misfires under load, hesitation, lost boost response and reduced fuel economy. It is a mileage-driven wear item, not a defect that appears suddenly, and is typically noticeable somewhere past 60,000-80,000 miles depending on driving pattern and oil change discipline.
Common Symptoms
- Rough or unstable idle, worst when cold
- Misfire under load or during acceleration
- Hesitation and reduced boost response
- Drop in fuel economy
- Check engine light with cylinder misfire codes
How to Fix
Confirm with a borescope through a removed intake runner before spending money - misfire codes alone do not prove carbon. The effective cleaning is mechanical: remove the intake manifold and walnut-shell blast the intake ports and valve backs, then replace the intake gaskets and spark plugs while everything is open. Chemical intake cleaners and fuel additives cannot reach the valves on a DI-only engine. To slow reaccumulation, fit a quality oil catch can on the PCV line, use a full synthetic that resists volatility, and keep oil changes at 5,000 miles. Plan on repeating the service roughly every 40,000-60,000 miles.
Sources for this issue (2)
The 3.5L EcoBoost's high-pressure direct (GDI) injectors run at diesel-like pressures and are a common failure item, especially at higher mileage and after heat-soak. A stuck-open or electrically failing injector floods a cylinder and can wash down neighboring cylinders on the same bank, producing a cold-start misfire that often smooths out once warm.
Common Symptoms
- Cold-start misfire / stumble that smooths when warm
- Rough idle and hesitation on acceleration
- Check-engine light, often flashing on start
- Fuel smell from exhaust, poor fuel economy
- Single-cylinder or same-bank multi-cylinder misfire
How to Fix
Read freeze-frame and identify the specific cylinder; compare fuel-injector balance/contribution data. Swap or replace the failed GDI injector (intake manifold removal required for access) and inspect for fuel-washed plugs. Replace plugs/coils on the affected cylinder if fouled. Verify high-pressure fuel pump output and low-side pressure to rule out supply issues before replacing multiple injectors.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
- High-pressure direct-injection (GDI) fuel injector — 2011-2016 3.5L EcoBoost (Gen 1)OEMBL3Z-9F593-BCross-refMotorcraft CM-5202 (superseded by BL3Z-9F593-B), Ford BL3Z-9F593-A (earlier revision, superseded), Ford engineering number BL3E-9F593-HB / BL3E-HB$95–$185
Sold individually; the engine takes 6 (Require Quantity: 6). Gen 1 (2011-2016) 3.5L EcoBoost is direct-injection ONLY, so this is the single injector type on the engine.
- High-pressure direct-injection (GDI) fuel injector — 2017-2020 3.5L EcoBoost (Gen 2)OEMHL3Z-9F593-BCross-refBosch 0261500307, Motorcraft/Ford service reference CM5254, Ford 82511115$66–$140
Sold individually; 6 per engine.
As an Amazon Associate, we earn from qualifying purchases; other part links may also earn au7o a commission. Confirm fitment by VIN before buying.
Sources for this issue (2)
P0316 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does P0316 mean on a Ford?
P0316 stands for "Misfire Detected on Startup (First 1000 Revolutions)." This code means the engine computer detected a misfire during the first roughly 1,000 engine revolutions right after startup. It is an early-warning indicator that usually accompanies other specific misfire codes (such as P0300 or P030X) identifying which cylinder is affected. The computer monitors crankshaft speed variations to catch combustion problems immediately on cold start. It can cause rough running on startup, hesitation, and may indicate a developing ignition, fuel, or mechanical fault. On Ford it is documented across 3 models: Bronco, Flex, F-150.
What are the most common causes of P0316?
The most common causes of P0316 are: Worn or fouled spark plugs, Faulty ignition coil(s), Faulty or clogged fuel injector(s), Low fuel pressure or weak fuel pump, Vacuum or intake leak, Carbon buildup or compression loss, Faulty crankshaft/camshaft position sensor. The specific cause varies by vehicle.
How much does it cost to fix P0316 on a Ford?
Published repair estimates on Ford range from $500 to $8,000 depending on the model and root cause. If an issue mentions a recall or campaign, check your VIN with the manufacturer or NHTSA and confirm eligibility and coverage with a dealer.
Looking for P0316 on a different make?
View P0316 across all makes →Join 700+ subscribers following Au7o for vehicle insights and updates.
Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.