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

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 Vehicle Noise, Vibration, and Harshness. Testing and Inspection