FAULTBASE
NEWSASKCars
© 2025 FAULTBASE
All rights reserved.
v2.0.0 • Production
ContactPrivacyImpressum
Home/Cars/BMW/3 Series/E90/E91 (2005-2012)/how to address P0302 misfire code in BMW 3 Series E90/E91 (2005-2012)

how to address P0302 misfire code in BMW 3 Series E90/E91 (2005-2012)

BMW 3 Series E90/E91 (2005-2012)

Severity: mediumDifficulty: mediumError Code: P03022-4 hours
3 min read
581 words

Problem Statement

## Problem Statement The P0302 code indicates a misfire in cylinder 2 of a BMW 3 Series E90/E91 (2005-2012). This can lead to performance issues and increased emissions.

Error Code
P0302
Repair Time
2-4 hours

Safety Warnings

  • ⚠Safety Warnings:**
  • ⚠Disconnect the battery before starting any electrical work.
  • ⚠Allow the engine to cool before removing components to prevent burns.

Symptoms

  • •Check engine light illuminated
  • •Rough idle or hesitation during acceleration
  • •Loss of power or acceleration
  • •Increased fuel consumption
  • •Engine stalling or difficulty starting

Diagnostic Steps

  1. 1Scan for error codes using an OBD-II scanner to confirm the P0302 code and check for any additional codes.
  2. 2Inspect the spark plug and ignition coil for cylinder 2, looking for signs of wear, damage, or carbon buildup.
  3. 3Perform a compression test on cylinder 2 to assess the engine's mechanical condition.
  4. 4Check the fuel injector for cylinder 2 for proper operation and any signs of clogging or leakage.
  5. 5Inspect wiring and connectors leading to the ignition coil and fuel injector for damage or corrosion.
  6. 6Examine the air intake and vacuum lines for leaks that could lead to an incorrect air-fuel mixture.

Solution

Solution

1. Preparation

  • Gather tools and parts required for the repair.
  • Disconnect the negative battery terminal to ensure safety.
  • Allow the engine to cool down before starting work.

2. Replace Spark Plug and Ignition Coil

  • Tools Required: Socket set, torque wrench, ratchet, extension
  • Remove the engine cover if necessary.
  • Disconnect the electrical connector from the ignition coil on cylinder 2.
  • Remove the bolt securing the ignition coil and gently pull the coil from the spark plug.
  • Use a spark plug socket to remove the spark plug from cylinder 2.
  • Inspect the old spark plug for wear; replace if necessary.
  • Install the new spark plug hand-tight, then torque to manufacturer specifications (typically around 22 lb-ft).
  • Insert the new ignition coil and secure it with the retaining bolt. Reconnect the electrical connector.

3. Test Fuel Injector

  • Tools Required: Fuel injector testing kit or multimeter
  • Disconnect the fuel injector connector from cylinder 2.
  • Use a multimeter to test the resistance of the injector; consult specifications for acceptable resistance values.
  • If the injector is faulty, replace it by removing any securing clips and inserting a new injector. Reconnect the electrical connector.

4. Check Compression

  • Tools Required: Compression tester
  • Remove the spark plug from cylinder 2.
  • Insert the compression tester into the spark plug hole.
  • Crank the engine several times and record the compression reading. Compare it to manufacturer specifications (typically around 120-200 psi).
  • If compression is low, further investigation into potential causes (valve issues, head gasket failure) is needed.

Verification

After completing the repair, verify that the issue has been resolved:

  • Test the affected component to ensure it functions correctly
  • Check for any error codes or warning lights
  • Monitor the vehicle for a few days to ensure the issue does not recur

Prevention Tips

To prevent this issue from occurring again:

  • •Follow the manufacturer's recommended maintenance schedule
  • •Address warning signs early before they develop into major issues
  • •Use quality parts and fluids recommended for your vehicle
  • •Keep detailed records of all repairs and maintenance

Tools & Equipment Required

  • Remove the engine cover if necessary.
  • Disconnect the electrical connector from the ignition coil on cylinder 2.
  • Remove the bolt securing the ignition coil and gently pull the coil from the spark plug.
  • Use a spark plug socket to remove the spark plug from cylinder 2.
  • Inspect the old spark plug for wear; replace if necessary.

Parts Required

  • Spark plug
  • Ignition coil
  • Fuel injector (if needed)

Additional Information

Error CodeP0302
Repair Time

2-4 hours

Difficulty

medium

Severity

medium

Tools

5 items

Parts

3 items

Related Faults

Discover similar issues

  1. my BMW 3 Series E90/E91 (2005-2012) window won't go up what could be wrong

    ## Problem Statement The power window on a BMW 3 Series E90/E91 (2005-2012) is not functioning and will not go up.

    Symptoms
    • •Window remains in the down position and does not respond to switch activation
    • •No sound from the window motor when the switch is pressed
    • +{count} more

  2. my BMW 3 Series E90/E91 (2005-2012) has a knocking noise from the engine what is it

    ## Problem Statement The BMW 3 Series E90/E91 (2005-2012) is experiencing a knocking noise emanating from the engine.

    Symptoms
    • •Knocking or tapping noise from the engine, particularly at idle or under load
    • •Decreased engine performance or power
    • +{count} more

  3. how to fix the weak airflow in my BMW 3 Series E90/E91 (2005-2012) AC

    ## Problem Statement The air conditioning system in a BMW 3 Series E90/E91 (2005-2012) is exhibiting weak airflow, indicating potential obstructions o...

    Symptoms
    • •Weak or insufficient airflow from the AC vents
    • •Unusual noises coming from the AC blower motor
    • +{count} more

  4. why does my BMW 3 Series E90/E91 (2005-2012) lose power when going uphill

    ## Problem Statement The BMW 3 Series E90/E91 (2005-2012) is experiencing a loss of power when driving uphill, which may indicate issues related to th...

    Symptoms
    • •Check Engine Light illuminated
    • •Engine stalling or misfiring during acceleration
    • +{count} more

  5. how to fix the steering wheel vibration in my BMW 3 Series E90/E91 (2005-2012)

    ## Problem Statement The steering wheel in your BMW 3 Series E90/E91 (2005-2012) vibrates, particularly at certain speeds or during braking, indicatin...

    Symptoms
    • •Steering wheel vibrates at specific speeds (usually between 50-70 mph)
    • •Vibration increases when braking
    • +{count} more

  6. my BMW 3 Series E90/E91 has water pooling in the passenger footwell, what could it be?

    ## Problem Statement The BMW 3 Series E90/E91 is experiencing water pooling in the passenger footwell, indicating a potential leak or drainage issue.

    Symptoms
    • •Water accumulation in the passenger footwell
    • •Damp or wet carpet material
    • +{count} more

Share this solution

Comments

Sign in to share your thoughts

Sign In

No comments yet

Be the first to share your thoughts

Back to Generation