Hey guys,

I'm new here and proud owner of a 2003 S-Type 4.2 V8 with 90k miles.

Ever since I bought it one year ago, it makes a weird "toot" noise under medium hard acceleration when I abruptly get on the throttle. In the linked video, you can hear it several times. It sounds like it's coming from the engine bay and can also be heard from outside.
The sound does not appear when accelerating normally or with kickdown. Do you have any ideas?


Thanks in advance!

 

That to me sounds like the throttle body.

Back in that timeframe ford had this phenomena in a lot of different models. The solution is/was to clean the TB and clean or replace the idle air by-pass (on cars which had it)

Now it could be other intake related things but I highly suspect its related the small passages in the TB, air bypass, or maybe EGR. (if equipped on this engine)

 

Thanks, this sounds like a plausible cause! I'll give it a try and tell you, if it helped.

 

My ‘02 V6 makes a quick “bark” noise if I mash the throttle hard. Not really a problem, but it alarmed me the first time I heard it. I think it has something to do with the intake runner valves changing positions quickly and affecting the airflow.

 

Maybe it's just happy?

 

I've removed all that black residue from the throttle body with a wet microfiber towel and so far, I couldn't replicate this sound. So thanks a lot, seems like this was the culprit

 

Cool, glad it seems to have helped.

I was a Ford design engineer in the mid 90s and since they owned Jag at that time, I also did design work on both S-type engines.
The Ford duratec V6 and the 4.6L "modular" V8s all had that problem. Some other models too.
Sometimes when the IAC valve would go bad the idle speed would be off, not idle, or make weird noises. I recall a hooting sound on one 4.6L T-Bird I had. Repeatedly cleaned the IAC and it would only be good for a week or so. Replaced it and never had that issue again.