FFFFFFFFFFFFFFFFT acceleration noise.

[GMINI]

Since I got snows on it seems I'm hearing a ffffffft increasing with acceleration. I don't really think it's the tires or I'd post elsewhere obviously.

I'm wondering if any s owners are noticing a pronounced fffffffft type sound accompanying the charger whine.

3 months and this is the first I've noticed. Could still be the tires.

Superchargers don't have a blower valve, do they???

[BruceK]

Quote:

Originally posted by GMINI
Since I got snows on it seems I'm hearing a ffffffft increasing with acceleration. I don't really think it's the tires or I'd post elsewhere obviously.

I'm wondering if any s owners are noticing a pronounced fffffffft type sound accompanying the charger whine.

3 months and this is the first I've noticed. Could still be the tires.

Superchargers don't have a blower valve, do they???

From what you describe, it sounds like it could be some sort of exhaust leak.

[GMINI]

ick.

Then I should be able to hear it standing still. Indeed.

Actually, dumb me, that would be a great way to rule out tire noise. Ooo. Also new skid plate. Maybe airflow noise

[BruceK]

Quote:

Originally posted by GMINI
ick.

Then I should be able to hear it standing still. Indeed.

....

Well, based upon my previous experiences with exhaust leaks (if that really is what your car has) I think the engine might need to be under load pressurizing the exhaust system if it is just a small leak. With the engine just idling you may not hear it.

[GMINI]

ahhhhhhhhh.

and since it seems not to be supercharger related maybe this thread needs a trip to faultsnfixes...

[Shaun]

A while ago I was accellerating hard onto a motorway and the exhaust sound sounded louder than it should the car has been in for a service since and is all fine (except the heater broke tonite yipee). I kind of like the sound it makes.

[pdubyab]

Sounds similar to a problem I had a few months ago on my Cooper. Never thought the dealer would succeed in tracking it down but they did. Turned out to be a split grommet/seal in the bulk-head by the driver's side footwell. I think it was where the accelerator cable went through and the split in the seal tended to open up as the pedal was depressed. No more "FFFFFFFFFFFTing" now!

Hope this helps.

PWB

[GMINI]

Quote:

Originally posted by pdubyab
Sounds similar to a problem I had a few months ago on my Cooper. Never thought the dealer would succeed in tracking it down but they did. Turned out to be a split grommet/seal in the bulk-head by the driver's side footwell. I think it was where the accelerator cable went through and the split in the seal tended to open up as the pedal was depressed. No more "FFFFFFFFFFFTing" now!

Hope this helps.

PWB

It should, pdubyab. Thanks.

Answer me this please: was it a constant or only sometimes. One drive or the other? One day on one day off (that kind of thing.)?

[pdubyab]

It was very much intermittent, with no apparent common cause. That's why I was so amazed when my dealer tracked it down and cured it. Maybe it's actually a known problem so they knew where to look!!

Good luck with yours GMINI.

[GMINI]

one more question for pdubyab:

Did yours whistle as well?

Mine seems to be temperature variant. Real cold produces a whistling noise.

Strange.

[pdubyab]

Quote:

Originally posted by GMINI
one more question for pdubyab:

Did yours whistle as well?

Mine seems to be temperature variant. Real cold produces a whistling noise.

Strange.

No whistle with mine, just a soft wind-rush noise - or, as you previously put it a ffffffffffffffffffffffffffft! It was certainly speed/acceleration-dependent and, possibly, temperature-dependent - the latter could have explained the intermittent nature of it.

Hope you track it down - it's damned annoying if you don't want to have the stereo cranked-up the whole time to drown it out.

[here2help]

Quote:

Superchargers don't have a blower valve, do they???

The supercharger incorporates a specially designed bypass valve.
This is actuated by a vacuum pipe near the throttle body and
re-circulates the supercharged air when there is a depression in the
manifold and therefore when boost is not required.
Cheers

[GMINI]

Quote:

Originally posted by here2help


The supercharger incorporates a specially designed bypass valve.
This is actuated by a vacuum pipe near the throttle body and
re-circulates the supercharged air when there is a depression in the
manifold and therefore when boost is not required.
Cheers

And so it is unlikely that such a valve would make any noise during acceleration... right?

[here2help]

Thats correct GMINI

[zipkarts]

There is a seal around the intake Plenum on the supercharger.I have replaced a few of these.What you are hearing is compressed air leaking from the super charger under throttle application.This noise can be easily listened to from the outside of the vehicle or by turning the ignition of.