Bad spark plug code#

Your 3 Series may not start if the spark plugs have worn too much, or if they have been contaminated due to improper combustion. The ignition system in your 3 Series will have to work a lot harder to be able to ignite the air/fuel mixture in the combustion chambers. When the spark plugs go bad, it is going to take longer for the engine to turn over and start. If your vehicle is getting significantly lower gas mileage than usual, its time to inspect the condition of the spark plugs. Poor fuel mileageĮxcessive fuel consumption is a common sign of bad spark plugs in 3 Series. The engine will not run smooth when idling, you may also feel vibrations in the cabin. Rough idleĪnother indication of bad spark plugs in BMW 3 Series is rough idle. When you press the gas pedal in your 3 Series, the vehicle may hesitate to accelerate and it will take longer to reach your desired speed. If the spark plugs are not generating sparks properly, the engine will lose power.

In case of doubt, check the condition of the spark plugs and replace them if found defective. However, it can happen that there are no error codes.

Bad spark plug code#

If you see any error code from P0300 to P0312, it indicates that there are misfires in the engine. To perform further diagnostics, you will need to connect OBD2 scanner to your vehicle. When one or more of the spark plugs start to fail or has failed in your 3 Series, it will cause the engine to misfire and the check engine light may illuminate in the instrument cluster.

Symptoms Check engine light illuminates due to misfires