70mm bbk throtle body

I have an 89 5.0 lx with trick flow intake and plenium with a 70mm bbk cold air intake and throtle body. My problem is a whistling noise coming from the center of the plenium. Has anybody had this problem? If so, what was your solution to fix this?

I have the 70mm BBK TB but on a 4.6L. Are you sure everything is tight and the TB gasket is in place correctly? I did have the TB screws come loose on me once after installing. Tightened them down a bit harder and no problems since.

Check the EGR & Idle Air Control valve seals too... Best to scrap off everything and use RTV

BBK throttle bodies are notorious for the whistling you described. Are you sure it’s coming from the center of the Plenum? Does it whistle under light throttle or heavy throttle? Also beware of the screws that hold the butterfly plate to the throttle shaft. They are also known to come lose.

My old motor did the same thing shortly hafter I installed a BBK throttle body. Eventually the throttle screw came loose and was sucked into the cylinder destroying the motor.

Also beware of the screws that hold the butterfly plate to the throttle shaft. They are also known to come lose.

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