KyAllroad (Jeremy)
KyAllroad (Jeremy) PowerDork
3/22/18 5:56 p.m.

BBK PowerPlus 70mm throttle body whistles like it's getting paid to do it.  It's a particularly ear piercing pitch at idle/very light throttle setting.  Any sage advice?

Woody
Woody GRM+ Memberand MegaDork
3/22/18 6:02 p.m.

Is your intake boot cracked? Maybe underneath where you can't see it?

KyAllroad (Jeremy)
KyAllroad (Jeremy) PowerDork
3/22/18 6:10 p.m.

Whistling worse with intake boot removed.  Seems strongly to be around the throttle plate.

barefootskater
barefootskater Reader
3/22/18 6:11 p.m.

They already circled the problem for you and highlighted it in blue. wink

Seriously though, check the throttle lever/rod/valve thingy for play. I know it is a problem on some TBs and carbs. 

stylngle2003
stylngle2003 GRM+ Memberand New Reader
3/23/18 8:53 a.m.

my wife's 2.4L 2008 Rav4 makes a whistle that corresponds to throttle position on the highway/above 60mph.  No visible leaks/cracks, nothing responds to starting fluid spray.

RossD
RossD MegaDork
3/23/18 9:04 a.m.

My first thought was a vacuum leak, but if the starter fluid trick doesn't give you a confirmation...

Clean the throttle body.

If that doesn't help, try to redirect the airflow into the TB. Turn the boot/elbow. Create turbulence or remove it. That kind of thing. It might just be the a hole in the butterfly that's whistling but that's only part of the mechanism that creates the noise. How the air is moving before it gets to the hole is part of it, and probably downstream too.

This explains whistles but not for the layperson...

Dr. Hess
Dr. Hess MegaDork
3/23/18 10:40 a.m.

I have two that whistle.  The 3SGTE in the RAV4 has a whistle from the Idle Air Control Valve circuit where the hose connects into the main intake just downstream of the air filter.  It's not "exactly" a stock setup.  I just live with it.  The 22R in the Truck has a whistle under some throttle conditions.  It will cycle on and off at idle.  Near as I can tell, it's related to the intake near where the filter (also a cone) is.  I live with that one too.

aircooled
aircooled MegaDork
3/23/18 10:46 a.m.

I had a carburetor that did that at idle once.  I never did see the exact cause, but it must have been a small burr on the plate or bore because taking a bit of emery cloth to both cleared it up.

Vigo
Vigo UltimaDork
3/23/18 11:46 a.m.

Lots of throttle bodies make lots of noise without the stock intake plumbing in place. It can't be called abnormal unless you know it didn't do it before and does do it now. Cleaning the throttle body/plate is the best first step. Past that you're off the map and just have to mess with the airflow in various ways until you stumble upon something that lessens the issue. 

KyAllroad (Jeremy)
KyAllroad (Jeremy) PowerDork
3/23/18 11:51 a.m.

In reply to Vigo :

Oh, it's clean.  Really really clean.  And while some intake noise is to be expected this is on a whole nuther level.  I first thought the alternator was failing.  It's so loud SWMBO complained about the whistle/shriek over the running, uncorked 302.  It's loud.

There is no hole in the throttle plate, should there be one for idle purposes?

I'll take an emory cloth to it this weekend and see if there is a burr anywhere.

freetors
freetors Reader
3/23/18 11:52 a.m.

I'd bet that adding one of those "tornado" things or maybe even just a trip wire in the right places inside the intake could disrupt the airflow around the offending part and make it stop.

aircooled
aircooled MegaDork
3/23/18 12:30 p.m.

Yeah, the noise I was getting was amazingly loud.  Like a small bird sitting on you shoulder and cheeping in your ear, very high pitched..  Easily heard over the exhaust and the fan, even with the air cleaner on.

Floating Doc
Floating Doc GRM+ Memberand Reader
3/23/18 3:44 p.m.

Sounds a lot worse after your description in the later posts. 

I would be curious to hear what fixed it. Good luck. 

Vigo
Vigo UltimaDork
3/23/18 11:14 p.m.

Ok, that's not a normal throttle body whistle. Does it occur during closed throttle, open throttle? Did it start as soon as you installed that throttle body or has that throttle body NOT made this noise, and now it does?

KyAllroad (Jeremy)
KyAllroad (Jeremy) PowerDork
3/24/18 8:04 a.m.

It's a "new to me" rebuild using all the old parts that were in use for years before.  It whistles at idle and very light throttle settings (just cracked open).  It's done it nearly full time since I got everything together.

***i suspected a leak around the shaft for a minute when I put a finger under it and pushed it went away.  But closer examination (with stethoscope) says it is the firewall side (the outward tipping) of the throttle plate.  No hole in the thing and it appears to be sucking so much air it can't get past the plate without noise.

Vigo
Vigo UltimaDork
3/24/18 8:01 p.m.

Looks like that throttle body still has air passages for an idle air control motor? Plug the inlet in front of the throttle plate with your finger while the engine is running and see if the noise stops. Most throttle body whistling that i know of is air going through the idle motor passages.

93gsxturbo
93gsxturbo Dork
3/25/18 8:31 a.m.

My BBK TB on my old LSC whistled too.  I think its just something they do.  My friend who is big into 5.0s always ran accufabs since they were quieter.

AngryCorvair (Forum Supporter)
AngryCorvair (Forum Supporter) GRM+ Memberand MegaDork
10/31/24 11:35 a.m.

Canoe

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