Quick whistle when off gas

[BigWill]

As the title sorta says above

This is probably nothing but I keep noticing it. Say I'm on the gas down the road, when I take my foot off, after about 2 seconds it makes a tiny whistle noise for half a second, now I'm a complete novice at engines so it's probably nothing, but would love to know what it is, thanks

 

[tom_ibiza]

what engine size you got? if its a small engine its probably the carb! nothing 2 worry about

 

[BigWill]

yeah, tis the 1.2

 

[tom_ibiza]

yup just your carb doing it they all do it! nothing to worry about!

 

[BigWill]

Cheers mate, least I know now

 

[Alex 17]

Cheers mate, least I know now

Passed ur test yet??

 

[Nath.]

Since when do fuel injected engines hav a charb

 

[bobmcgod]

Since when do fuel injected engines hav a charb

I was thinking this...
But I am going to listen out for such a noise when i go out later.

 

[tom_ibiza]

single point injection still got a carb on em take off the air box youll see it with the butterfly flapping around!

 

[ettlz]

single point injection still got a carb on em take off the air box youll see it with the butterfly flapping around!

Isn't the 1.2 MPI? Even the entry level VAG engines from the late 1990's had one injector per cylinder. There's still a flappy intake valve in the throttle body, though.

 

[tom_ibiza]

it may be i cant remember to be honest havnt looked into it in depth, me and a friend looked at it and both came to the same conclusion it looks like a carb it sounds like one, it may not be one tho i dont no.........

anyways thats wats making the noise from what you describe anyways its just the rush of air as the butterfly opens and closes.............

 

[Leigh15]

The 1.2 is 12v - so yes, it's MPI

 

[ettlz]

The 1.2 is 12v - so yes, it's MPI

The 6-valve version is also MPI... has any leading motor manufacturer used single-point injection engines in the past five years?

 

[Nath.]

it may be i cant remember to be honest havnt looked into it in depth, me and a friend looked at it and both came to the same conclusion it looks like a carb it sounds like one, it may not be one tho i dont no.........

anyways thats wats making the noise from what you describe anyways its just the rush of air as the butterfly opens and closes.............

I think all the 1.2 engines have muli point injection so the injectors are mounted directly to the inlet manifold.

Normally the single injector setups have 1 injector that pulses 4 times per crank cycle mounted into a throttle body and that is then mounted to the manifold.

Sort of like a carb but not a carb as the fuel is injected into the manifold rather than sucked through the carb in.

 

[BigWill]

Passed ur test yet??

Nah not yet, not long till the next though

I see there's been much discussion about this, I would have just accepted the carb theory, as I'm a nonce on engines

 

[scottyNI]

my 1.2 doesn't make that noise...

 

[woza135]

The flappy thing is the throttle body! My 1.4 formula sport makes a weird whistle kind of noise when off the throttle or on the throttle slightly sounds like the same thing..

anyone else have this with the 100bhp 1.4? or normal 1.4