Neutral Run-Up Test

This test is designed to identify vibrations which are related to the speed of the engine. Use this test when the customer has a concern with vibration at idle, or as a follow-up to the downshift test. This test probably doesn't apply when the complaint is related to vehicle speed only (appearing at the same vehicle speed regardless of the engine speed).

CAUTION: Refer to Road Test CAUTION in CAUTIONS and NOTES.

1. Slowly increase the engine speed while looking for disturbances that match the customer's complaint.
2. Observe the engine speed (RPM) and the frequency (if possible) where the vibration occurs.