Any time I drive, especially if I select a gear(4 speed auto) and engine brake, or lightly accelerate, I get this god awful rattle in my engine bay. Its loud enough to hear inside with music at a moderately low level. Its been going on since I bought the car a few months ago but has been getting louder. I mean my car is nowhere near perfect but this is something I've never heard in my life. Its like... hemi valve tap mixed with a loose heat shield and power steering pump without fluid at full crank, all at once. It a nasty sound. Unnoticed at low speed(5mph) and idle or in park, neutral or reverse. Just when I'm driving down the road. When I get into it, it magically disappears. It needs a valve cover gasket but that would be absurd for it to be the problem. Maybe I should get a trans from Japan Direct or a low mile trans from a junkyard?

 

it could be the motor mount or the tranny mount. I couldn't tell you unless you have to visually inspect it and look at all four mounts. three on motor and one on the tranny. Which I could be any more help. Tranny do not rattle, but definitely would feel harsh shift, won't shift when it should or a clunk .