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.
A faulty ignition module can cause a vehicle to overheat. The vehicle may run and then lose power suddenly due to a rise in the engine's temperature. Once the engine cools, the vehicle will start and run until it overheats again.