My camrys been making some really odd noises lately. It makes a sort of knocking sound when I'm stopped at a light and in Drive. It stops if I shift it to N or P. The sound seems to happen only after the cars fully warmed up. It's also intermitten, it'll happen maybe at 9/10 stops I make. There seems to be some oil on top of the transmission too which I dont know was there earlier or not since I never really looked there. This car seems to be just falling apart now

It has 117k miles, 4-cyl, and is a 2000 camry LE
Anyone know of a good trusty mechanic in central NJ area? PM me