On my 1992 mustang gt, someone was listening to my car....... it makes a noise, its kinda in between a ticking and knocking sound, hard to tell where its coming from, this person said it sounds like the valve is pushed out of its seat. My car smokes, knocks/ticks.............is there anyway that i can confirm that he is right about the valve???????????? It kinda makes sense in away, the sound does seem like it comes from one side of the engine and smokes mostley off that one cylender head(pipes straight off each head). help!!!!!!!!!!