Pinpoint Test B: Drumming Noise

WARNING: This page is about a different car, the 2013 Ford F-550 Super Duty, 2013 Ford F-450 Super Duty, 2013 Ford F-350 Super Duty, and 2013 Ford F-250 Super Duty. However, it is still accessible from the selected car via links, so may be relevant.

B1 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: Locating Tail Pipe And 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.
- Determine the amount of vibration that occurs with the drumming noise.
- Is the noise/vibration reduced or eliminated, or does the noise/vibration occur at a different RPM?
- Yes : REFER to EXHAUST SYSTEM ALIGNMENT - GASOLINE ENGINES or EXHAUST SYSTEM ALIGNMENT - 6.7L DIESEL . TEST the system for normal operation.
- No : CONDUCT a diagnosis on other suspect systems. REFER to NOISE, VIBRATION & HARSHNESS .