Every time I turn the car off I hear a noise from the throttle body, it sounds like a power antenna going down, does anyone know what can be causing this.
2003 s-type 3.0

 

Anyone

 

Since it happens every time, open the hood/bonnet and have a friend shut the motor off while you listen for the noise, you may have to do it a couple of times to narrow down the problem. Sorry thats all I "got".

 

A hissing noise from the throttle body after switch-off may indicate worn swivels on the axis of the throttle itself. Spray a little heavy grease from outside onto the swivels, allow solvent to evaporate, then test. If the hissing has gone or is much modified then you need a new/recon. throttle body. This is a common problem with most cars if a high-ish mileage has been travelled, and upsets the computer by altering the manifold depression at idle. This problem of course can only happen with petrol engines. Also the same hissing sound can come from anything connected to the inlet maifold, e.g. a small pipe connected to a pressure sensor, the powered brake vacuum connector etc.
Leedsman.

 

But is it a HISSING sound? I didn't interpret the post that way. A better description of the sound and how long it lasts for would be useful, maybe.

 

it sounds like the butterfly on the throttle body is closing after I turn the car off, the noise just last for a few second.

 

Maybe they all do it? Maybe only some are audible?

It's drive-by-wire so the PCM can do as it likes with it, of course.

 

I got a hiss on shutdown, just lasts a second. How about you post a video/with sound clip so we can here. I'll do the same, we'll compare notes.

 

Mine does exactly the same and I too have only just noticed it. If you remove the air pipe you cannot push open the butterfly valve as the motor is keeping it closed, that's where the buzzing noise is coming from. I cannot though find any reason for this to happen so it might well be a fault.

 

I'll post a video tomorrow with the sound

 

I know exactly what you mean. Mine does it too. I liken it to a jet engine spooling down, just really, really quiet.

 

How do I post up a video clip

 

gonna have to host it at photobucket.com or other freebie website...be careful, sometimes it limits the size of the file, and/or length of the video.

 

youtube, post the link here.