Engine Mounts

Engine mounts support the engine and isolate vibration and torque reaction from the chassis. On diesel pickups and trucks, mounts carry high torque loads and heavy vibration, and rubber deteriorates with heat, oil leaks and age.

Mount types

• Rubber-bonded mounts – steel plates or brackets vulcanized to natural or synthetic rubber. Most common on pickups and trucks.
• Hydraulic mounts – fluid-filled chambers that dampen vibration more effectively, used on many SUVs and passenger vehicles.
• Active or vacuum-controlled mounts – switch damping characteristics electronically, on some newer vehicles.
• Torque rods and struts – limit engine rotation on transverse layouts.

Position and fitment

Longitudinal pickup engines are typically supported by left and right side mounts plus a rear transmission mount, while transverse engines use left, right and front or rear torque mounts. Left and right mounts often differ, and 2WD and 4WD versions may use different mounts or brackets. Manual and automatic transmissions can change mount stiffness and design. Specify by OEM number, position, side and bracket layout.

Failure symptoms

Excessive vibration at idle, clunks on take-off or gear changes, engine movement visible under throttle and, in severe cases, fan contact with the shroud or stress on exhaust and hoses. Oil leaks soaking rubber mounts are a frequent root cause.

Applications

Diesel pickups such as the Mitsubishi Triton and trucks such as the Isuzu NPR put heavy loads on mounts. Mounts are frequently replaced together with transmission mounts.