BMW 325 Intermittent Shudder: Worn Spark Plugs and Separate Fuel-Filter Service
A BMW 325 at 120,000 km had an intermittent idle shudder and slight acceleration hesitation without a current DTC. Six removed spark plugs showed severe center-electrode wear and source-reported gaps above 1.3 mm, supporting degraded ignition performance; plug replacement addressed the confirmed fault. A never-recorded fuel-filter replacement was handled as a separate maintenance item because the source publishes no pre-repair fuel-pressure measurement proving restriction caused the shudder.