Pinpoint Test F: Drumming Noise

WARNING: This page is about a different car, the 2005 Ford RV Cutaway, 2005 Ford Econoline, 2005 Ford E450 Super Duty, and 2005 Ford Cutaway. However, it is still accessible from the selected car via links, so may be relevant.

F1 CHECK THE EXHAUST SYSTEM
- Key in START position.
- Increase the engine rpm until the noise is the loudest. Note the engine rpm.
- Key in OFF position.
- 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 And Front Exhaust Pipe
  Courtesy of FORD MOTOR CO.
- Key in START position.
- Increase the engine rpm and listen for the drumming noise. Note the engine rpm if the noise occurs.
- Key in OFF position.
- Using a vibration analyzer (VA), 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 : CARRY OUT Exhaust System Neutralizing . TEST the system for normal operation.
- No : GO to F2.
F2 POWERTRAIN/DRIVETRAIN MOUNT NEUTRALIZING
- Carry out Powertrain/Drivetrain Mount Neutralizing . Test the system for normal operation.
- Is the noise reduced or eliminated?
- Yes : Vehicle OK. TEST the system for normal operation.
- No : CONDUCT diagnosis of other suspect components.