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.
When changing an engine mount at home, never support the engine with a jack or jack stand. The weight of the engine sitting on the pinpoint head of a jack or jack stand can puncture the oil pan, or crack other components. The engine should be supported by an engine brace from the top.