Give a little whistle....

[KKson]

Went for a blast in the 390 this afternoon and when i came to start it up there was a light whistling noise. It sounds as if there's an air leak somewhere - I've checked the extra air valve hose, all vacuum pipes, including servo, breather hoses, plenum hoses etc but can't find anything. The connector onto the servo spins quite easily if I rotate it but the noise doesn't appear to come from there. Anyone had this before? I checked the plugs and they do seem to be running a little lean.

[AM400]

Do you have a rising rate fuel regulator fitted? I used to get a whistling from mine so I replaced it with a Webber Alpha.

[KKson]

Thanks for the reply but no, the car is fitted with an old Webber unit already. It's a new noise that only started the other day. The noise reduces when I open the accelerator?

[celcius]

Hi keith
Might be loose trumpet

[ElvisWedgeman]

Cooling system ???

Tony. TCB.

[PoleDriver]

Sounds like somewhere on the inlet tract.. anything from the first inlet pipe right through to the trumpet base (or plenum body)

[KKson]

Found it! The whistling was from the plenum bypass/idle screw. It's not exactly a tight fit, so I've put some heavy duty grease on the little bugger and all is now quiet again.