Strange air related sound

[TeGriffic]

The Griff (pre cat) has developed another strange noise and I'd appreciate any pointers. It sounds like air flow related and I can hear a constant static pitch hiss from the engine (very similar to a steam kettle, but it's not the swirl pot). If I even breath on the throttle it goes up a few octaves and appears constant still. It doesn't vary with revs but it changes, in a binary fashion, when I touch the throttle even slightly. It is evident, but only just, at idle. Head under bonnet, it sounds like it coming from the general area of the front of the engine, perhaps around the distributer.

Any clues as to what it might be or tricks to isolate the sound exactly would be much appreciated. Hopefully it's not serious cos I taking thr cat away for a few days.

Thanks for any help.

Edited by TeGriffic on Friday 11th August 19:03

[Ballistic Banana]

Has the Vacum pipe come of the Dizzy to Plenum( is it on there on early ones..I think maybe not!!)

BB

[Paul V]

Sounds like it could be one of the intake pipes or vacuum pipes could be leaking.

[tvr4ever]

Ballistic Banana said:

Has the Vacum pipe come of the Dizzy to Plenum( is it on there on early ones..I think maybe not!!)

BB

Mines a 1993 version and has the pipe (connected !). And yes it could be a disconnected vacume pipe.

Fred