I have an automatic V6 96 Camaro. There is a whining noise that seems to be coming from behind the engine. It is heard when the vehicle is hot. When you turn the vehicle off, the sound is heard as it dies down as if letting out some sort of pressure.. What could it be??

 

Going by what you are saying it could be an whine form the front pump of the transmission or the torque converter.

In my experience the torque converter sound a lot like a power steering pump low on fluid and tends to be loudest starting from a dead stop. The noise is more based on load of the engine. The front pump is more about the speed of the motor and not as load sensitive.

Either way it does not matter much both of those failure cause small metal fragments to go through out the inside of the transmission and should require a completer tear down to clean out the whole think. If I just installed a new torque converter I would expect to see the car back within a month with a internal seal cut by metal shavings or a stuck valve in the valve body. If you are going to tear down an older transmission you might as well rebuild it.

Course all of that is solely based on you description and could be completely wrong.

 

lets see, makes noise after engine is turned off, whats back there on the v6? 3.8? egr, evap, is fuel pressure regulator back there on 3.8? is it hissing,,, if cat is plugged bad pressure builds up. start checking hoses back there. i am going to say check the evap hoses

 

My bad, I read it a little too quick. What Craby said.

You could try it with the gas cap off. if it is not there with the gas cap off then it is a evap noise.

 

Post an audio clip.