My Crossfire Coupe 2005 auto, which I've had since 2008, has started making loud fluting noises when driven from cold. The colder the weather the louder it flutes, particularly on acceleration. Pitch changes with each gear change. Noise lessens as engine warms and disappears altogether at normal running temperature. Car drives normally, whether fluting or not, and does not make the noise when idling. Our local mechanic serviced the blower fan, which had started to fail intermittently and suspected as the source of the noise, to no avail. Two recent events in the summer may be relevant: 1. the prop shaft bearings were replaced; 2. I stopped briefly on one occasion and was unable to restart - nothing at all happend when I turned the key. Never happed before. After an hour or so it suddenly started normally.

Any ideas what is causing the fluting noise? My mechanic has spent some time on it but can't yet figure it out.

 

By fluting noise do you mean a whistling sound? If that's the case, I would guess that maybe your top center windshield trim piece is lifting while driving. There are 2 holes under it and the air may be whistling as it's lifting. I would check for this immediately so that you don't loose that center piece.
Even if I'm wrong it's still worth checking.

 

Thank you for the suggestion, M60A3Driver, but we've been through the common causes such as the one you suggest, to no avail. The noise is deeper than a whistle and varies with temperature, gear and speed, so sounds like a flute or oboe or clarinet or saxophone - take your pick! - until it disappears when the engine is warm. I think it must be to do with the mechanics but can't figure out what. The car has only done 62,000 miles, by the way, and drives normally apart from this mysterious noise. I suspect it is related to the recent replacement of prop shaft bearings but mechanic says no. Any other ideas?

 

The no start situation may be a failing CPS. They fail when hot and work after cooling.

 

That is a really weird problem. I'm at a loss as to what could be causing the noise. Hopefully someone who has had a similar problem will see this and have an answer. Best of luck!

 

Hi I think my car is making exactly the same noise, did you ever find out what it was? I can send a recording of it. My car is also a 2005 auto coupe.

 

No, the noise is still a mystery. As the car appears to drive completely normally apart from the noise when the engine is cold, I have decided to wait it out until whatever it is develops, as it surely will, and manifests itself in a way that points to the fault. I just hope it doesn't suddenly break down in an awkward place!
I will post the finding if and when I get to the bottom of it. In the meantime any other suggestions on what is causing my beloved Crossfire to blow like a flute when cold would be much appreciated.

 

Thanks for the quick reply, I notice that you had your propshaft bearing replaced, I had mine done the day before I first noticed the noise but the noise was very quiet then and seemed to be from the lower dashboard area so I dismissed it as a coincidence. It is much louder now and at its worst when the car is cold.
I have a good recording I can send you by email if you would like to compare it to yours?

 

What a coincidence! Yes, do send a recording to david_hemsworth@msn.com.

 

On it’s way, thanks for your help

 

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Just to 'throw-it-out there, have you checked (both members) for an air leak in any of the vacuum lines? Along those lines, does engine vacuum enter into the passenger compartment in dash area (HVAC or any valves inside dash)? IF SO, maybe a short burst of starter fluid or carb cleaner (along with listening for engine RPM increases) might help Must mention, be aware of sparks present where you are spraying (which is why only SHORT bursts of spray).


.

 

Thanks for the suggestion, I was led to believe that it was a vacuum leak noise and have spent hours trying to trace it. I took the battery and its tray out to follow a grey vacuum line which enters the cabin under the left corner of the windscreen / scuttle area. Inside the car it leads to a vacuum reservoir behind the glovebox (RHD car) and feeds the re circulation flap when the button is pressed. This reservoir is often wrongly assumed to be part of the central locking system. I disconnected this grey pipe from the cabin so I know this isn’t where the noise is coming from.

 

there is an actuator for cabin air door right above and to left of the grey vacuum reservoir youve disconnected. That actuator , if it leaks will make the noise. Its about two inches high and an inch wide, oval shaped and is unlabelled in the parts manual but is drawn in. it operates a spring in the cabin air box that its attached to. The part is unobtainium. I managed to get a new one but havent tackled getting it in. Theres a steel bar in front, and removing the whole dash doesnt look like itll improve access. Its hard to localize the noise, its high pirched and your ear doesnt easily have directional capability with it. its like a dog whistle. You can stop it by putting the control swithch to the dot just above the zero on the AC/htr head unit. Then no fresh air, and it will also whistle probably while the ac and or heat is actuated from 1-5. Pain in ***.

 

Hi Robert, if the actuator is for the air recirculation flap it’s activated by vacuum pressure from the grey reservoir box that you mentioned behind the dashboard, mine is a right hand drive car so this box is behind the glovebox on the left side of the dashboard and I can see it by removing the trim panel under the dash and shining a torch up behind the glovebox itself. You can disconnect the vacuum supply to this reservoir by blanking off the grey pipe from the engine, it runs under the battery tray and through a rubber grommet into the interior of the car. I tried this on mine to eliminate it from my inquiries, but the noise didn’t stop, the heater and air con still works but the recirculation switch doesn’t, this doesn’t bother me so I’ve left it like that and I will switch the fan off if I want to stop the outside air coming into the car, my early cars didn’t have a recirculation feature and I find that using it steams the windows up after a few minutes anyway. I hope you get yours fixed and if you don’t fancy dismantling your dashboard you could blank off the grey pipe like I did. I made a post about this noise recently, it’s entitled central locking vacuum valve box. Best wishes!

 

thanks.
Eventually the noise will occur while AC/heat is running at various speeds. Unless you leave the tube clamped off at the grey box(reservoir). Also the actuator gets its supply of vac from the solenoid, also right there by the grey reservoir,, if you follow the green hoses; this one has to be clamped off as well, if the leak is there. I havent replaced the actuator, (everything works for me, including the cabin air door,as for you, )due to hand surgery that precluded cramming myself and hands up under the dash. Ive had glovebox out for three months now, while procrastinating the actuator replacement. Problem is that actuator has a spring and is tucked up in there, so I know I can get it out, but unsure about getting the new one in. Final plan is to clamp off as you did. One caveat is that it is very hard to tell where the noise is coming from under there. Clamping at different places, and then driving for awhile makes the diagnosis.If your door is stuck closed, no fresh air. If its a convertible, hardly a problem....
Cheers.
BTW the grey reservoir is just for the cabin door; It doesnt have any function for the central locking sysytem

 

It sounds like it’s quite a difficult repair, especially under your circumstances, so you could try disconnecting the supply of vacuum from the engine and see if that works. Apparently the default setting for the recirculation flap is open, allowing fresh air in, so it’s fail safe and this is why I disconnected mine a few weeks ago, I’ve had no problems with condensation etc since then. When I disconnected the vacuum supply I cut the grey pipe in the engine bay right near the battery and pushed the ends of the grey pipe into small pieces of rubber hose which were blocked at their other end so the engine wasn’t pulling in excessive air through it, I thought this would be easier than trying to clamp the grey pipe as it’s made of quite a hard material and it would be difficult to seal properly this way. Good luck with yours.

 

Hi there,
Mine 04 Coupe makes (what sounds like) a similar noise (like a kettle whistling when it's boiled on gas). I've been told it's the baffle plates in the exhaust. Happens mostly around 1500 revs.

 

Hi Julzy my car made a strange noise part way down the exhaust too, it was like a tinkling noise and turned out to be a broken catalyst, the garage opened the exhaust up with an angle grinder to remove the broken ceramic parts and then welded it back together, it’s been fine since then and that was several years ago. I wondered if it would affect the annual emissions tests but it still passes comfortably every time.