Pinpoint Test A: Drumming Noise

WARNING: This page is about a different car, the 2010 Mercury Milan, 2010 Lincoln MKZ, and 2010 Ford Fusion. However, it is still accessible from the selected car via links, so may be relevant.

A1 CHECK THE EXHAUST SYSTEM
- Start the engine.
- Increase the engine rpm until the noise is the loudest. Note the engine rpm.
- Ignition OFF.
- Add approximately 9 kg (20 lb) of weight to the exhaust system. First place the weight at the tail pipe and test, then at the front pipe.
  
  Fig 1: Identifying Tail Pipe & Front Exhaust Pipe
  Courtesy of FORD MOTOR CO.
- Start the engine.
- Increase the engine rpm and listen for the drumming noise. Note the engine rpm if the noise occurs.
- Ignition OFF.
- Remove the weight from the exhaust system.
- Is the noise/vibration reduced or eliminated, or does the noise/vibration occur at a different rpm?
- Yes: REFER to EXHAUST SYSTEM ALIGNMENT . TEST the system for normal operation.
- No: CONDUCT a diagnosis on other suspect systems. REFER to NOISE, VIBRATION AND HARSHNESS (NVH) .