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 the head gasket begins to fail, The engine may have no symptoms at all. Symptoms only begin to occur when the leak has reached an engine oil passage, engine coolant passage, or the engine cylinder. Once the leak has reached one or more of these critical areas, the engine will react in one of a few ways.