BMC Carbon filters installed, car whistling please help

[ardy6931]

Hey guys,

I just finished up the first round of mods to my car, APR chip, Tubi exhaust, BMC intake and some interior GT parts.....( love the gt wheel )

I installed each part over a course of a month, i just added the new filters and ever since i got the car back, when I press the throttle not instantly but at about 5% throttle instead of hearing just the roaring engine sound I am hearing a high pitch whistle/hiss....

I don't know if its just the sound of more air being pushed through or if it is an issue...please let me know if anyone has experienced this

[technomania]

hi there, when i had the bmc filters aka ppi airbox installed, there was a louder air intake noise, which was the result of installing the box, but have to say it was on the V8 and I liked it

[harrison]

BMC is simply the maker of the filters. Depending on the manufacturer of the MANIFOLDS-there could be an issue. The stock filter/manifold,(a one piece affair) have locator tab notches, that need to be silicone filled on the STOCK air box-manifold area -with PPI manifolds. Otherwise the two small air hole leaks could produce a whistle. Make sure the airbox is completeely sealed. Apart from the three intake areas. The small screen on underside and intakes at blades-DUH.

[Europrice]

Possibly a vacuum leak somewhere or something not totally installed properly. The whistle sounds like air being drawn in through a small leak and when you really get on it there is so much air being drawn through it goes away or you can't hear it over the exhaust/engine.

[ardy6931]

thanks guys, check the suggested items above and no luck. The BMC filters compared to the stock filters are so thinly netted that i think the whistle just may be the sheer different in amount of oxygen getting sucked in initially....i have had the tabs and surroundings of the manifold sealed and tested.....still the same thing, if i put old filters on sound is gone, new filters its whisltin.g

[LAT]

Did you test the MAF inputs for leaks. It doesn't take much to whistle.

I have the Carbonio set up, it is louder and no whistle.


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[AJR8]

I have BMC twin air filters on(the same used by PPi)...without any expensive PPI or carbonio "holder"...just bolt it on with airbox NOT sealed (you can even see part of the filters with the airbox close) and I have no whistle! But I put only a Twin air BMC 76mm diameter...

[harrison]

??? very strange.

[LAT]

I have BMC twin air filters on(the same used by PPi)...without any expensive PPI or carbonio "holder"...just bolt it on with airbox NOT sealed (you can even see part of the filters with the airbox close) and I have no whistle! But I put only a Twin air BMC 76mm diameter...

Not clear on how you did this can you post pics?




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[AJR8]

I only have this pic...when I clean them again I'll post a photo from the back!

But even in this photo you can see that the filters are directly bolt to the OEM air intake...BMC twin air filter (3 inch/76mm diameter). I put a 3 cm rubber seal between the filter and the air box below the filter to hold them up so they didn't move around. I have already done 11k miles and no problem at all...no whistle, no drone...only better downshifting revving !

I refused to spend 1k for a quite useles mod as air filters.