2005 Audi A4 Repair and Maintenance
A guide to problems, costs, maintenance and repair for your 2005 Audi A4
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2005 Audi A4 ProblemsEngine Misfire Due to Failed Ignition Coil, Spark Plug, or Ignition Wire
An ignition coil or spark plug may fail unexpectedly resulting in an engine misfire and possible illumination of the Check Engine Light. Vehicles equipped with spark plug wires may also develop a misfire caused by a failed spark plug wire.
Popping sounds from the rear of the vehicle may be heard moments after starting the engine, or when slowing to a stop. This noise is from the leak detection pump filling the fuel tank with air, and releasing to retest the system when it finds a fault. The sequence of faults identifying this issue are as follows:
- Succession of loud pops from rear of vehicle
- Pops go away, and fuel economy decreases
- Check engine light illuminates
- OBD trouble code P2404 and/or P0441 is stored
- Engine will not start after refueling (must crank for over 30 seconds)
- Vibration when slowing to a stop
The cause is a valve which is mounted on the front of the intake manifold, commonly called the N80 valve, or EVAP system purge valve. The valve is designed to open under specific circumstances, but a worn valve will remain open at all times, preventing the pressurization of the fuel tank.
Correction of the issue is to replace the N80 valve with the latest revision.
Clogged drains can allow rainwater to accumulate in the plenum tray (at the base of the windshield). The water may leak into the vehicle's interior, brake booster, or electrical components, which can lead to major problems. Our technicians recommend keeping the tray clear of leaves, pine needles, and other debris.
2005 Audi A4 QuestionsBrake lights go on overnight. Batt & alt were replaced & brake lt switch. Same P (1 answer)
Intermittent. Always overnight.
2005 Audi A4 RecallsPassenger Frontal Air Bag Inflator Ruptures On Deployment
The passenger frontal air bag inflator may rupture on deployment, causing metal fragments to come through the air bag and injure occupants. Dealers will replace the passenger frontal air bag inflator free of charge to resolve the concern.