I have a hissing sound coming from what sounds to me to be inside the plastic cover over the throttle body. Getting annoyed.

Have not had time to take everything apart, but hope to start looking tomorrow.

Any idea what this could be?

I have a volant CAI, hissing started about 3 months after install.
I dont think its the IAC., truck is running normal no codes.
Throttle body cleaned less than 6 months ago.
Also not exhaust, all new.

Any opinions welcomed.

Michael

 

Sounds like a small vacuum leak.

Denny

 

The PCV plumbing elbow right at the throttle body, most likely.

 

Yes it was! Good call.

Sending Reps your way, thanks

 

Glad we could help