I know there was a recent thread on this but I still can't figure it out.

After shutting down, there is a loud hissing sound coming from under the battery on the passenger side. I read before it was something to do with the AC but I havn't had the AC on in months. Could it be a cracked line in that area?

thanks

 

Need more info;
Does it make this noise if the HVAC controlls are turned off at shut down?
As in a coupl emin before you turn the truck off turn the HVAC controll to the off position then see if it's still making this noise.
I'm betting it's the turbo spinning.

Keep in mind your turbo is still spining for a little bit after you turn the key off.

Dan

 

I too think its your turbo you are hearing...

 

If the HVAC is set to defrost the A/C is being used for drying out the air. If so what you are hearing is the high pressure side of the A/C system bleeding down.

MikeyB

 

It could also be the pressure being relieved form the turbo after shutdown. Check the turbo hoses and make sure they are all tight.