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.
Engine Misfire. Engine Misfires can be very difficult to diagnose. If the engine is misfiring, it can cause all sorts of problems and leave you guessing as to what is the root cause. When the engine misfires, you will lose power, your gas mileage will drop and the vehicle can even fail emissions.