Definition of quantal. 1  1 [Latin quanti how many, plural of quantus] : of, relating to, or having only two experimental alternatives (such as dead or alive, all or none) 2  2 [quantum] : of or relating to a quantum.
3. Engine movement. Another symptom of bad or failing engine mounts is an engine that moves in the engine bay. If the engine mounts are in good condition, they should be able to secure the engine firmly in the engine bay.
An engine mount, made of rubber and steel, has two purposes. One, it secures the engine and transmission to the frame of the car, and two, it absorbs the road shocks and engine vibrations so that the driver does not feel any engine movement. Transmission mounts secure the transmission.