JDM_TJ

its d15b2 bottom and y8 head.
its recently just startted to idle at 2 grand ive messed with the adjuster on the t b both of them and didnt really make a difference. theres alot of air coming from the back of the block above the oil filter and below the intake mani. i figured i blew the head gasket but i have no overheating issues and the water in the car is clear. also not leaking oil ????

some one help me pleasee !!!

p.s also makes like a weird noise when i shut the car off. its sounds like a huge valcume leak. but dont know where it could be coming from. all lines are good and connected ???
im clueless...