88scgt

we just built my engine, and i have this god awful whistling noise from my intake. we have changed the gaskets. narrowed it down to the vacum line under the intake any guesses

50mikey

Well I know when I put the larger TB on my TFR intake it started whistling pretty loud, loud enough I had one guy thinking I had a blower. I calmed the whistle down a lot by cleaning up the IAC and put the rest of my CAI on to the fenderwell. might just be these intakes...unless you have horrible driveability or loss of power.

88scgt

i think it is the intakes. i do have a 75 mm tb so i have no clue. say the whistling is louder than my blower. the next thing we are goping to try is repluging the vacum ports on the bottom side of the intake. thanks for the feedback, if anyone else has some answers as to what this is it would be greatly appreciated

Obsol3te

?
Confused as to what you're asking because you said you know where it's comming from.
Vacuum line under the upper manifold.
Get a smaller hose for it, or a new one(may be old and weathered)
If not you could be all ghetto with RTV see if that stops anything

chath_brick

this is from BBK's website:

Q. Why does my throttle body whistle? What can I do?
(part numbers affected include: 1501, 1503, 1514, 1517, 3501, 3502, 3503, 1534, 1536, 1537, 1539, 1540, 1542, 1543, 1544, 1522, 1523, 1524, 1715, 1700, 1701, 1703,1580, 1705, 1711, 17110, 1755, 1708, 1709, 1710, 1721, 1756, 1757, 1546, 1547, 1752, 1753, 1751, 1754, 1548, 1552, 1652, 1723, 1716)

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.
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88scgt

thanks guys. we no where it is coming from, not the vacum lines(new) but not sure why it is or why it is making this noise. seems like there is alot of people with the same problem with bbk tb

1fastzook

i have a bbk tb and it use to whistle pretty loud but then i backed out the screw on the bottom of the tb and it helped quiet it down alot now it only whistles when i hold it at 1100 rpm.

wjw61287

i was having same problem hmm that is nice to find out i was told it was normal

g2_5point0

When I installed my CAI, it whistled and still does. seems normal to me. Without silencers and whatnot, it's just natural that you'd hear some kind of airflow. however that port maching TB answer does make a lot of sense

gspfunk

You can also try drilling a small hole in the TB blade. Start w/ 1/8" or smaller. that will allow some of the airflow thru that hole instead of around the outside diameter of the blade while it's almost closed like it is at idle. You may need to readjust your idle screw afterwards since airflow will increase slightly.