Pinpoint Tests

Exhaust System

Pinpoint Test

Pinpoint Test A: Drumming Noise

This pinpoint test is intended to diagnose the following:
- Exhaust system


PINPOINT TEST A: DRUMMING NOISE

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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.
- 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 Exhaust System Alignment. TEST the system for normal operation.

No
CONDUCT a diagnosis on other suspect systems. REFER to Noise, Vibration and Harshness Testing and Inspection.

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