Hey guys, I also had just a stillen intake / z tube before installing my 5/16 iso thermal copper spacer. Same thing here, strange sucking/whistling sound almost like I'm boosted coming on around 2000-2500 RPM under load, wasn't there before, pretty loud, definitely sounds like a leak but I double checked everything. Idle is fine, car of course feels little more snappy but the sound is driving me nuts n making me concerned, in park when I rev you hear just the intake but in drive when I rev I hear that loud whistle / sucking sound, thinking about redoing everything from step 1 for peace of mind, anyone else have any input ??

 

Five years ago I had the spacer, the z-tube and the all my breathing mods installed at once. WOW! For a while I thought something was wrong, then at 3000RPM's I felt the xtra power. You'll be fine, enjoy.

 

i didnt want to make a new thread so decided to post here... i got the same issue i gaint the hp but also gained this noise.. can someone help me..this is the noise

 

I didn't get that noise you have, but I did gain a new hissing, whislting, boost type of sound that comes under load and I emailed Tony, and he said as long as you checked your hoses and there's no leak, if the car is idling normal, its okay, and that half the people report the sound and the other half don't

 

That noise while idle sounds like you have a leak

 

maybe you got that noise because ur missing a few bolts from what i noticed in the vid

 

I have the same sucking/whistling sound that occurs at 2500-2900 rpm when I floor but idle sounds fine. Is this normal also sounds like a squeak sometimes. I have a stillen z tube combo the oil gasket is not pinched i checked did anyone solve this issue or or this a normal thing?

 

You just added a mod that will let your engine breathe a whole lot better. Did you expect your engine to stay quiet? Lolz its normal for your engine to be louder when you add stuff to it

 

The loudness is fine I can live with that I actually love the sucking in sound it makes its the winning and squeaking that concerns me between 2500-2900 rpms that worries me. But i guess this is a normal thing with most installs for the plenum spacer.

 

Everyone that installs one get the same sound even me and it's normal I didn't do any thing wrong it's just the extra air moving threw your throttle body and plenum I pesonaly love the sound it makes but to each ther own

 

Ditto, i get a brief whistle/boost type sound everytime i get on the throttle after an upshift. sounds good to me

But seriously tho OP, you should retorque those bolts with a functioning torque wrench and make you tighten them in the correct order/pattern. otherwise you could split the manifold in half from improper tightening (since its a casting)

 

I have the same issue and this thread is finally starting to make me feel "normal"

A. Couple month ago I installed a Z-tube (very first mod). Minute HP increase, slightly deeper, louder at higher RPM's (consistent with what most others say). Also, cleaned MAF, TB, air filter and did ECU reset/relearn. Everything is cool.
B. Couple months later, I installed 5/16 copper spacer and Mrev2 at the same time. Install was easy, took it super slow, followed everything to a "T", torqued to 40/80/100 in lbs exactly as instructed, all hoses connected, no pinched oil filler cap, removed OEM gasket, oiled new one, plastic spacer caps all in place, etc.

After the spacer/Mrev2 install my intake makes 2 separate noises:
1. When parked, I can "blip" the gas, and the intake will make a BOV type noise. With the hood up you can clearly hear/see it's coming from the intake (not the manifold). Z-tube and OEM filter is installed correctly. Pretty sure this is "normal". Experienced a similar noise on a previous car with a CAI install, makes sense with more air.
2. I usually get a high pitched wheezing when accelerating. Doesn't do this in neutral when rev'ed (I'm 6MT). It's a bit inconsistent, I can't/haven't isolated it to a specific RPM, but I often get this semi-piercing whistling when under throttle - and usually louder under heavier throttle. I did a ECU reset/relearn, but no change.

I'm 99% certain my installs are good and even Tony from MD ensured me this is normal, but I still find it a bit odd not everyone has this issue because there's hundreds of people on here with my exact same mods

 

I'm sure the whistling sound or the boost sound is the intake/z-tube combo. I had a rebuilt G that had a cone intake that would whistle or sound like a boost when I get on the gas. Than I sold it and picked up a clean G35 with no mods and when I got on the gas, didn't hear anything, When i installed my JWT pop charger on the new G, I'd hear a whistle or a boost sound when I get on the gas. Hope that clarified some things here for you guys.

 

I also installed a MREV2 and the 5/16 plenum spacer with the ISO copper thermal upgrade recently with no hissing or constant whistle. I did however forgot to plug in one of the vac lines and had RPMs jump back and forth but corrected the issue and my baby has been running strong.

 

yup thats a normal sound ( not the video, thats definitely a leak)