4.6 DOHC whistle/whine at idle...

[cefolar]

Technically it's not a mustang, but hopefully someone here can give me some ideas. I have a 47' Ford with a 97 4.6 DOHC Cobra engine. The motor runs great and the car runs great, but at idle after reaching operating tempurature I get a high pitched sqeal coming from somewhere and it is driving me NUTS!!

I have changed the idler pulley and the tensioner. The odd thing is, when I shut the car off the whine slowly fades - like when you let the air out of a balloon by stretching the opening to make a squeal sound. It doesn't stop abruptly when the engine is shut down.

It does not sound like it is coming anywhere around the transmission (a 4R70W AODE). Any advice that anyone in the forum can offer is appreciated...

 

[CENTENNIALSTANG]

hose maybe

 

[Skud]

Are you using the IAC or is it a carb setup?

When I put in a restrictor plate for the IAC to help with the hanging idle problem it did the exact same thing you're describing.. It would wistle at idle and when I shut the car off it would slowly (maybe 2 - 4 seconds) go away.

Could be the IAC if you still have it..

Riley

 

[cefolar]

Checked all the hoses and they are all good - motor doesn't run like it has a vacuum leak anywhere. I will go and pickup a new IAC, not sure how it works to makes that sound but I read that somewhere before.

Thanks a ton for the advice!!

 

[lvmustanggt]

mine 2002 mustang gt whistle like crazy , don't know where it's comming from. I some how like it cause people think it supercharger

How can I take care of this problem. I got 42000 miles on my car

 

[CENTENNIALSTANG]

mine 2002 mustang gt whistle like crazy , don't know where it's comming from. I some how like it cause people think it supercharger

How can I take care of this problem. I got 42000 miles on my car[/QUO

I bet its the harmonic balancer pullie. LUBE that BEITCH UP. mine honestly did that 2 on my 03 GT and i thought it sounded sweet to then i ordered some Under drive pullies from steeda.

 

[Kilgore Trout]

Sometimes a new Gator Belt can "whistle"... Sounds are tricky to diagnose over the internet...

 

[blkhorse]

well it can only be one of two things,trapped vacuum bleeding off. are your heater contols run with a vacuum resevior?.the other could be coming from the A/C unit if you have it working(pressure equalizing)..you can eliminate belts, idler etc by just removing belt and see if noise goes away

 

[lvmustanggt]

mine 2002 mustang gt whistle like crazy , don't know where it's comming from. I some how like it cause people think it supercharger

How can I take care of this problem. I got 42000 miles on my car[/QUO

I bet its the harmonic balancer pullie. LUBE that BEITCH UP. mine honestly did that 2 on my 03 GT and i thought it sounded sweet to then i ordered some Under drive pullies from steeda.

i do have steeda UDP.

 

[blkhorse]

pulleys, belts, etc won't keep making noise when engine has stopped rotating

 

[the98stang]

I bet it's a vac leak. It would be consistant even after the motor is shut down.