So i did this install all by myself and I have to say it was pretty damn easy just took about an hour and a 1/2....make sure you have all the correct tools before you start.

I put everything back and everything runs and sounds fine at idle...the car drives great but when I floor the car I can hear a loud sucking sound (never heard before)

Im assuming it is just the intake sucking in alot more air now that it has the spacer am I correct?

seems to have much better throttle response and has more uumph when getting on it.

so far I like it and the sound just want to make sure the loud sucking is ok.

also if u are debating on getting this and the installation is stopping you dont let it its quite easy.

03 coupe 5at

well the sucking could been a bolt or 2 that where not tightened down all the way, ORRR maybe you bolted down the plenum on the oil gasket thing that sticks out and its letting air in, do u have stock intake?

You may have a vacuum air leak somewhere. Make sure the rubber piece around the oil cap didnt get stuck when putting the plenum on.

i agree, sounds like a vaccum leak somewhere. check your gaskets, you might have pinched it or something so its not lying evenly.

Thats a pretty common thing that people miss. Make sure that rubber isnt stuck in there

There's no vacuum leak. If you had a vacuum leak, your car's idle would be terrible, by way of unmetered air entering the engine.

The noise is more than likely just the air filling the intake up. Just like the extra noise you get if you put a cold air intake on.

If he only added an spacer.. the sucking noise is not the intake getting more air. As others have said either the gasket is being folded over or pinched when he did the install.. check your bolts.

I only have a Ztube.....I made sure the oil rubber wasnt stuck in there so it isnt that....I put the new gasket over my old cause someone said that was fine. The torque wrench I rented didnt work right so I did as the manual said and used a socket screwdriver and put them in as hard as I could.

I also put back all the vacuum hoses just like i took them off...

would the ztube help make the sucking or do u think my bolts are not tight enough.....

IT is ONLY when I floor the car , normal driving i dont hear it at all and it runs/drives fine.

yeah, i have the same whistle and others have reported the same thing after the spacer. you are fine.

Well if you're flooring the car, of course you'll hear a sucking noise. That's the car gasping for air.

The Z-tube, FWIW, or at least from what I saw when I had my Z, is a pretty noisy stock intake.

So yes. Z-tube + MD spacer will make a sucking noise under heavy throttle. It's perfectly normal.

Same thing I have, same spacer + z-tube. Normal under WOT. The spacer does change the acoustics a bit more in the intake mani, I'd call it a deeper sound.

No engine light then your fine. And if you wanna make sure just retorque everything and make sure there nothing pinched.

I believe the noise you're hearing is from the z-tube and by installing the spacer you've corrected Nissans design flaw allowing way more air to the front ports. I would get a torque wrench and make sure those bolts are tight enough, not something you want to guess at....Gary

This!!!!! I had the exact same thing. Relax just intake bud

Ahh the sound of power