P0316: Misfire Detected on Startup
P0316 indicates that the engine control module (ECM) has detected a misfire within the first 1000 revolutions after engine startup. This is often caused by fuel delivery issues, ignition problems, or mechanical faults that are more pronounced when the engine is cold. The code is set when the crankshaft position sensor detects irregularities in rotational speed, indicating incomplete combustion in one or more cylinders. Common triggers include weak spark plugs, failing ignition coils, clogged fuel injectors, low fuel pressure, vacuum leaks, or internal engine wear such as low compression. Because it occurs at startup, it may be intermittent and harder to diagnose.
01. Most Common Causes
- Weak or worn spark plugs
- Failing ignition coil(s)
- Clogged or leaking fuel injector(s)
- Low fuel pressure (failing pump or regulator)
- Vacuum leak (intake gasket, PCV hose)
- Low engine compression (worn rings, valves)
02. Symptoms You Will Notice
- Rough idle or stumbling at startup
- Check Engine Light illuminated
- Engine hesitation or shaking when cold
- Possible hard starting or extended cranking
03. Step-by-Step Diagnosis
Step 1: Scan for additional misfire codes (P0300-P0308) to identify specific cylinders.
Step 2: Inspect spark plugs and ignition coils for wear, carbon buildup, or damage.
Step 3: Check fuel pressure with a gauge; should be within spec (typically 35-65 psi).
Step 4: Perform a cylinder compression test to rule out mechanical issues.
Step 5: Smoke test the intake system to find vacuum leaks.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended. Driving with a misfire can damage the catalytic converter and cause further engine damage. Have it diagnosed promptly.
How much does it cost to fix?▼
Cost varies by cause: spark plugs ($50-$100), ignition coil ($100-$200), fuel injector ($150-$400), or fuel pump ($300-$600). Diagnostic fees are typically $50-$150.