i have a Camry 00 4cyl model, i just had the car back since my cousin crashed into a pole , minor damaged , just had to replace front bumper and bonnet , engine left undamaged. but when i got the car back from mechanics , the rev was not normal , at stationary , the rev is below half way from 0 to 1 revs (around 0.6rev) , engine struggling to keep it self running . when i drive it , foot on gas , it struggles to increase rev with a rattling sound , 3 secs later it moves a little and i stalled (auto not manual) at the lights , not being able to turn on engine for another 2 mins , and i smelt this oily smell to . anyone know whats wrong with my engine ? what i can do to fix it ?