.it happened 3 times after the timing belt changed.if i put my hand on the timingbelt cover i can feel that ticking every time it happened.it only happened when i dont drive it for some days.then the ticking comes whenever idle or maybe while driving(i dont konw, cant hear). if i drive it everyday,this never happen,what ever i start her up a cold morning or drive it in a hot day.but last night it happend all of a sudden,i start it as normal,but the car shake badly and the engine sound like 70's american musle car for the firt few seconds,and goes smooth but with the ticking noise,so i let it idle for a while untill the water temp comes up then i drive it to a car wash about 5 kms away,found the ticking has gone.car is a 96 r33 gtst. but i am still worry it,what it could be, i want to fix it asap b4 a big mess