high-pitched sound from F355

I have a similar whistle, although faint...... sounds kinda cool!!

 

When you first start the 355 you will hear the whistle/whine of the fuel pump. You should hear it for about the first 3 minutes (or so) when starting from cold.

Perfectly normal...

 

Get a mechanics stethescope, or a peice of tube to listen with, and try to find were the hit pitch is coming from.

It could be a loose accessory belt, loose vacume tube, a bearing going bad, a leaking exhaust header, etcetera.

So find where in the engine bay the noise is coming from.

 

It sounds like you are describing the air injection pump. If the fuel pump stopped making noise after the first 3 minutes or so the car would stop.
The noise made by the immersed fuel pump pretty much requires a stethescope to hear.

 

i have the same noise... a high pitch sound that last until car has warmed up. i didn't notice it until i had my 30k done............

 

Rifle - I stand corrected and you are absolutely correct... Got my pumps backwards.

 

Yep - exactly - air pump.
If you want to be 100% sure... Start the car cold and open the hood. Stand at back of car. The pump is located in the right rear corner of the engine compartment, right by your turn signal/brake light assembly. You'll see a black canister and the sound will be coming from there

 

What is the purpose of the air injection pump, and why is it so audible during the initial warm up phase.

 

I asked my mechanic about this about two weeks ago, specifically regarding Rich's prior car (355), and was told that the air pump is an emissions control item. If I have this right, I believe he said that it injects air into the exhaust system to help burn (?) unburnt hydrocarbons that pass through the engine before the car has warmed up. He said that my 328, instead of an air pump, has a valve that brings in more air through a venturi effect, thereby accomplishing more or less the same thing.

 

A few years later and you guys still talk about my 355

I told you - you should have bought her...

Now don't miss out on the Gallardo for Sale!!!

Rich

 

As Cincy said, it is an emissions item. It only runs for 2-3 minutes when the car is cold. They are noisy because over time, the impellar of the pump (made of plastic) gets brittle and starts to break up causing a different flow of air from when it was initially designed, and intact.