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.