whistle at low idle

[hivolt5.0]

I have a whistle noise coming from my motor when the idle is around 800 rpms, any higher RPM and the whistle goes away. The sound seems to be coming from the intake.

I've adjusted the idle speed, cleaned the IAC motor and adjusted the timing, but the whistle is still there. Any ideas on what would casue this?

 

[bullitstang1313]

Sounds like a vacuum leak. I'm currently fighting the same issue with mine. It drives me crazy. I would check all vacuum hoses and fittings to make sure there aren't any leaks.

 

[iLkYsPoNy]

An aftermarket throttle body will whistle. I have a BBK 75mm t-body and it whistles like crazy!

 

[Distortion 5.0]

Check the PCV valve. My bronco II used to whistle when the PCV valve was bad.
If that's not the case, then you can use throttle body cleaner to track down any possible vaccuum leaks by spraying all the vaccuum lines and fittings while the engine is running. If idle changes, a leak is indicated.

 

[Deleted member 87397]

It's probably the throttle body. A lot of the aftermarket ones whistle at low rpm.

 

[hivolt5.0]

Thanks for the replys.

I did replace the PCV valve thinking that might be the culprit but it wasn't.

I haven't checked all of the vacuum lines yet, but that will be my next course of action. So would a vacuum leak stop whistling when the throttle was opened up some? Because the whistle goes away once the RPMs go up.

As for the TB, it is a Professional Products 70mm and it would only whistle when I turned the motor off, but now something is whistling all the time.

I'll keep checking....

 

[iLkYsPoNy]

I heard the PP T-body is notorious for the whistle... just like the BBK

 

[Italian-LX]

I heard the PP T-body is notorious for the whistle... just like the BBK

Yep, I had a 70mm that whistled really bad at idle.