Am I going nuts or did my OEM recirc valve get LOUDER?

[vtluu]

I like to think I'm fairly well attuned to the various sounds my Evo makes, after driving it in all sorts of street and racing conditions for over a year. So I don't think it's my imagination that for the past week or so, the stock OEM recirc valve seems to be louder than before. :shock:

Whereas before, whenever I'd hit the gas, spool up the turbo and then let off, I'd hear the usual "breathing" sound of the recirc valve, now I hear a soft little "whistle" initially, too. If I could "spell out" the sound it'd be something like a mid/high-pitched "fiwww" sound if you can imagine that. I'm pretty darned sure it didn't sound like that before. The turbo still seems to be boosting normally and power delivery feels normal. No change in the idle characteristics either. I don't see anything unusual in the intake system either. (Stock airbox, Blitz panel filter which I've had for months now.) It could be the colder weather/atmospheric conditions but I doubt it.

Anybody have any idea what it could be (other than my imagination), and/or if I should be worried?

[EVO GRIM]

I know that that sound is much louder when you take out the air filter. Check to see if the air box is closed correctly.

[vtluu]

I've checked it but will double-check it again (and also the seals on the MAF box, and other parts of the intake plumbing) tonight...

[SouthernCrane]

Perhaps you have a leak somewhere? But I would think if there was a leak you would feel some loss in performace, which you are not. :?

[559EVO]

It might not be working correctly and causing turbo surge,or if you have messed with it lately it might be installed backwards.My friend learned the hard way o that one.

[Deviousone209]

i put on a turbo xs intake and my stock rec. valve got louder...i think its just cuz of the intake sucking in more air.

[vtluu]

i put on a turbo xs intake and my stock rec. valve got louder...i think its just cuz of the intake sucking in more air.
An aftermarket intake will make the recirc valve almost sound like a BOV.

In my case however I've made absolutely no changes to the car since it started sounding different...

[Deviousone209]

oh...then i dont know, you got me on that one..

[evoredy]

vtluu,

you probably are experiencing more dense air released out of the recirc. valve due to cooler ambient temps. a positive change in boost will definatly change the recirc's initial fiwwww noise frequency.

also, I am not sure about the reliability of our plastic valves, but maybe repeated shifts and driving characteristics under bosted conditions could wear out the spring (not sure though)or the diaphram will not move as freely as when it was new-purely speculation.

in other words, if all hardware and connections are ok-youre ok. check ALL vacume lines and check your filter element for holes.

if it bothers you to where you lose sleep, you will need a second opinion from someone in or out of the car.

[vtluu]

Thanks, the car still pulls and boosts normally so I'm going to check a few things and not worry about it any further.
Actually it boosts pretty darn strong with the cooler temperatures, as you say. :skid: