Engine Misfire Detected on Startup (First 1000 Revolutions)
What does P0316 mean?
The P0316 code means the vehicle's onboard diagnostic system has detected: Engine Misfire Detected on Startup (First 1000 Revolutions). This is a moderate severity code.
Common Symptoms
- Engine misfires during cold start
- Rough idle for first 30-60 seconds after starting
- Check Engine Light illuminated
- Engine stumbles or almost stalls on startup
- Misfire clears after engine warms up
Probable Causes (Ranked by Likelihood)
- Worn or fouled spark plugs Very High
- Leaking fuel injectors allowing fuel to pool overnight High
- Weak ignition coil that fails when cold High
- Low fuel pressure on initial startup Moderate
- Worn valve seals allowing oil to foul spark plugs overnight Moderate
Step-by-Step Diagnostic Procedure
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Check for companion misfire codes (P0301-P0312) that identify which cylinder misfires on startup
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Remove and inspect spark plugs -- look for oil fouling, carbon deposits, or worn electrodes
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Perform a fuel pressure leak-down test -- pressure should hold for at least 10 minutes after shutdown
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Test ignition coils for resistance when cold and again when warm to check for intermittent failure
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If spark plugs show oil fouling, inspect valve stem seals for leakage
Frequently Asked Questions
Can I drive with code P0316?
Yes, you can drive short distances. The misfire typically clears after the engine warms up. However, repeated cold-start misfires can damage the catalytic converter over time.
Why does my engine only misfire on startup?
Cold-start misfires often occur because spark plugs are fouled with oil or fuel that leaked past injectors overnight. The engine requires richer fuel and stronger spark when cold, so marginal components fail under these conditions.
Is P0316 mainly a Ford code?
While P0316 is a generic OBD-II code, Ford vehicles are the most common to set this code. Ford PCMs are particularly vigilant about monitoring misfires during the first 1000 crankshaft revolutions.