Drive Engine Run-Up (DERU) Load Test
WARNING: This page is about a different car, the 2006 Mercury Mariner and 2006 Ford Escape. However, it is still accessible from the selected car via links, so may be relevant.
To carry out this test, proceed as follows:
- Block the front and rear wheels.
- Apply the parking brake and the service brake.
- Install a tachometer.
- Place the vehicle in DRIVE, and increase and decrease the engine rpm between idle and approximately 2000 rpm. Note the engine rpm and, if possible, determine the vibration frequency.
- Repeat the test in REVERSE.
- If the vibration/noise is duplicated when carrying out this test, inspect the engine and the transmission mounts.
- If the concern is definitely engine speed-related, carry out the ENGINE ACCESSORY TEST to narrow down the source.
- Proceed as necessary.
WARNING:
Block the front and rear wheels, and apply the parking brake and the service brake, or injury to personnel can result.
CAUTION:
Do not carry out the Engine Load Test for more than 5 seconds or damage to the transmission can result.