Air Leak....New BBK Plenum

mar04GTStang · 10-27-2006

hey guys....I just bought and installed the new BBK plenum for my 04 GT. The install went fine. I tightened everything down and connected all EGR valves and hoses and the IAC and everything. Everything appeared to be fine. I start the car and it sounded funny, it's a whistling sound...I shut the stang off and I can still hear air traveling up and out through the area of the plenum.

I need to know how I can find an air leak or how to figure out what this problem is and where exactly the air is coming from. I don't know if for some reason it's supposed to sound like this, I doubt it. I let it run a little while to allow the computer to register there is a new part under the hood and lower the RPM's but it still continued with that sound. When I installed my new Throttle Body this didn't happen. I'm assuming it's an air leak.

If you could please help me I would appreciate it.

reivaxtorres · 10-27-2006

if its not too much trouble just take it all off again and make sure everything is where its supposed to be. 99+ intakes didnt have the separate plenum-to-intake gasket, those should have it built in, just make sure something didnt get in the way or anything. did you keep the gaskets that go between the plenum and the throttlebody/egr/tps? all those gaskets should be able to be reused. also check to make sure that you didnt accidentally unplug something else. when i 1st installed all those parts on my car, i did have a whistle sound too, but it was only when i was driving and it went away eventually as the parts settled in.

SharonReborn · 10-29-2006

i hope this helps. i found it at performancecenter.com under BBK products "click for more info" underneath the throttle body image. you might want to check it out for more info. here's a little.

Q. Why does my throttle body whistle? What can I do?

A. Turbulence in the airflow stream can create a whistle. This can be created by sharp edges in the air intake system, most notably when a larger throttle body is used on a stock intake that has not been 'Port Matched.' The air along the outer edges of the air intake system and throttle body hits the "wall" of the smaller intake manifold, creating turbulence that can cause a noticeable whistle. Other trouble areas can be the small vacuum ports and the IAC (Idle Air Control) valve port which may empty into the main bore of the throttle body. If these edges are square enough at the entry point of the bore, it can create turbulence, and the air will whistle passed it (similar to blowing over the top of an empty cola bottle just right to get it to whistle).

BBK offers a 1 year manufacturers warranty against any defects in materials or workmanship. If you feel that the ports of your throttle body are creating a whistle, you can request an RGA number (Returned Goods Authorization number) and return it to us, at which time we will inspect your piece, and further hone as you may feel it to necessary. Alternatively, if you would rather keep possession of your throttle body, and you feel you are adept enough with simple hand tools, you may want to try and hone the ports yourself with fine grit sandpaper. Some customers are adept enough with a small drill or Dremel-type tool to lightly sand the edges down. Be aware though, that any irreparable damages done to the product on the customers behalf cannot be warranteed by BBK. If you feel that you are not capable of the task or do not want to risk possible damage, BBK strongly urges you to send the part in under warranty. Be aware though, that further honing the throttle body will not cure any whistling issues if the problem actually lies elsewhere in the system, and if the added airflow of a larger-bore throttle body is only making the problem perceptible.

http://www.performancecenter.com/pro...1/Mustang/4.6L

mar04GTStang · 10-29-2006

i don't know if this is my problem....my throttle body is OK i think because i installed that first while still using the stock plenum and everything was fine with no whistle...once I installed the BBK plenum i noticed the whistle.....i'm not sure what's going on....

mar04GTStang · 10-29-2006

back to the gaskets though.....i received all the parts and gaskets in a bag from BBK but i did notice that they didn't give me a gasket to go between the plenum and the actual intake manifold....i wasn't sure if i received one and lost it or sometihng or you're just not supposed to place a gasket there because there wasn't one on the stock plenum to intake manifold....

i was talking to my dad about this and he mentioned the possibility of it being a vacuum problem or vacuum leak.....

the whistle sounds like it is coming from the TPS area......

i don't know I might have to take it apart and just start over and do it again

SharonReborn · 10-29-2006

have you checked that info?
http://www.performancecenter.com/pro...1/Mustang/4.6L

it has more FAQ.

the98stang · 10-30-2006

Does the car idle fine? Or does it idle differently with the BBK? If it idles fine, I wouldn't worry about it.

You can always use soapy water to see if it IS coming from that area. Or put seafoam in the intake system.

mar04GTStang · 11-01-2006

no it idles fine, a little high but I think that's because the computer has to get used to new equipment on the engine....I'll try some soapy water or just take it apart and do it over again...i would just leave it but it's obviously sounding like that for a reason and air leaks can't be a good thing down the road....unless it's suppose to sound like that which i doubt it

So Money · 11-01-2006

I have installed a TB / Plenum combo in my car with zero whistle - I would take off the plenum and and make sure the gasket between the TB and plenum i alligned properly - it is such an easy install that it shoould come off pretty easy

meatball · 11-03-2006

Quote:

Originally Posted by mar04GTStang

"you're just not supposed to place a gasket there because there wasn't one on the stock plenum to intake manifold...."

There is a gasket (o-ring) between the stock plenum and the stock intake; pics in my Gallery; might have gotten crimped or damaged.

puppynut5 · 11-05-2006

One way you can find a leak if your sucking air is this.... Pick up a bottle of Carb Cleaner and spray little bits around where you think the leak is while your car is running. Just do short sprays because when the Carb cleaner gets pulled in by wherever the suction is it will rev the engine up a bit... Once you get it to rev up you can narrow it down and hopefully find out where the actual leak is. Thats what I had to do when I had a vacuum leak in the lower plenum of my Intake Manifold.