I installed the motordyne 1/2'' spacer about a 1-2 weeks ago. It made the sound deeper. But in the last couple of days, i have noticed a higher pitch kind of like a whistling noise coming from the engine. Usually comes on when i go pass 2.5k rpm. I was wondering is this from the spacer? and is this a normal sound if it is? and if not, what do you think could of caused this noise, i have never heard of it before.

 

Its actually more like a high pitch whine, when im around 2.5k rpm and up, once i let off the throttle the whine would stop, once i get back on it, you would hear the whine again. and Everytime i shift gears, the whine would be quieter and slowly get louder again as the rpms climb, but when my rpm are totally up ( near redline) the whine sounds less again (might be cause of the exhaust note getting louder, im not sure. =P) Im not sure where the noise is from, but it sounds more like its from the front than the back. But im not totally sure. Also when im standing outside of the car, you dont really hear the whine as much, maybe cause of the exhaust note, but when im inside the car, with the windows up, the whine is louder. And when my car is parked, and i press on the throttle, the high pitch whine seems to be less, its only louder when im doing actual driving. Also, i have a 5at, if that helps. Could this be from the spacer? or is it something else?

 

Sound like your plenum is leaking. Try re tightening you plenum bolts they can work themselves loose

 

All intake mods (CAI and spacer and whatever) make wierd sounds. Its just the volume and velocity of air increasing. You get what you get.

 

A new whistle sound is common with the spacers due to the increased plenum internal volume. The plenum becomes a larger vaccum chamber that fills as you tip into the throttle.

It is the tipping in that creates the whistle sound as air rushes past the opening throttle body. So the whistle sound is actually comming from the throttle body.

You can sometimes briefly hear the same whistle when you shut off the engine.

Could this be what you are hearing?

 

I dont know if thats the sound, it sounds like a high pitch whine whenever i play with the throttle and when i go past 2.5k rpm. I mean it doesn't sound bad or anything, its just a sound that i have never heard of and i didn't hear it when i first installed the spacer. So im just worried that maybe something is wrong. I hope thats the sound, because atleast it means my car is fine. Ill try to pay even more attention to the sound and see if it appears as i turn off my car. Thank you.

 

Well one thing for sure is that a 1/2" spacer can dramatically change the induction sound. Definetly deeper and louder. Maybe if I was there I could tell you but its hard to say over the internet.

 

The whistle sound is LOUD when you shut it off, open ur hood, and shut ur carr off in a garage and ull definatly hear it. I think ur fine, itll always make more noise when u add any intake or exhaust items.

 

Ok i just got back and i still cant figure out where the sound is coming from. the sound is louder when im sittign in the front of the car compared to the back. How exactly does the whistling noise sound? Because the sound i hear sounds kinda like the high pitch part of a fire truck siren. of course its not as loud but the note is similiar. When i shut off my car i dont really hear it although i just parked outside and i didn't try to pop up the hood to listen. But from inside the car, i didn't hear anything. Also i can only duplicate the sound while the car is in motion. If my car is in neutral and i rev or if im parked and i rev the car, i dont hear anything. Are these similiar to the symptoms experienced from the whistling? Im starting to worry that it might be something alot more serious, such as a tranny issue or something. Its hard for me to locate the sound because i can only duplicate it while the car is in motion. The sound appears once i go past 2k rpm, no matter what gear im in. My mods are topspeed headers, nismo cai and the 1/2'' spacer, and a 3.5 differential. Again, i dont mind the sound if its normal, i just dont want it to be a sound of something wrong. And it just doesn't seem right, because if its the whistling sound i should be able to hear it when im reving on neutral right? If it is something wrong, i just want to make sure its not caused by the aftermarket parts i installed, cause then i can bring it back to the dealer.

 

I say bring it into a shop and get an opinion. Try to determine if its a air leak or mechanical vibration. Another option is to remove the spacer and see if the sound changes.

Let me know what you find.
Tony

 

Im pretty sure its not a vibration because it doesn't sound like it. About the whistling noise, can you duplicate the noise for sure, if the car is parked and you rev the car with the hood popped up? I think i might just do that one more time with the hood popped up and my ears close to the plenum. just to make sure if it is indeed a normal sound or not.

 

If you are sure its not a vibration thats good. And if you are sure it only happens when you are driving, it suggests its not a vaccum leak because the engine is under load.

In which case, the sound you hear is normal for a breather mod.

 

Yeh i was about to say, if the noise happens only under load, then its normal.