F150online Forums

Strange noise on shut down

Thread Tools
 
Search this Thread
 
  #1  
Old 01-04-2008 | 03:47 PM
corvetteguy's Avatar
Thread Starter
|
Senior Member
Joined: Nov 2007
Posts: 163
Likes: 0
From: pa
Strange noise on shut down
My 97 F150 4.6 auto makes a
strange whirring noise which seems
to wind down for 30 or so seconds
after shut off.
Any idea what it is?
 
Reply Like
  #2  
Old 01-04-2008 | 03:59 PM
Bluegrass's Avatar
Senior Member
Joined: Jul 2004
Posts: 6,196
Likes: 38
From: Easton, Pa.
A sensor that has vaccum applied and is leakng down after the motor is shut off. Normal. Most of the time you don't hear it.
 
Reply Like
  #3  
Old 01-04-2008 | 08:10 PM
Bent6's Avatar
Senior Member
Joined: Jan 1999
Posts: 724
Likes: 3
From: Great Lakes
It's just vacuum in the intake. To confirm this, just floor the gas pedal after the engine shuts off. Instead of a slow leak, all manifold vacuum will be gone instantly.
 
Reply Like
  #4  
Old 01-04-2008 | 11:42 PM
Pheonixx's Avatar
Senior Member
Joined: Oct 2007
Posts: 579
Likes: 0
From: Buffalo, NY
mine does this too, never noticed until i put on the aftermarket air filter and modded the airbox. if you have aftermarket intake you will notice the sound alot more than if you didnt have it.
 
Reply Like
Back to Subforum
V8 Engines
View Next Unread
5.4 Build up




Advanced Search
Quick Reply: Strange noise on shut down


Reply Closed Thread Share

All times are GMT -4. The time now is 10:15 AM.