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I installed a gt40 intake on my motor swap the upper was port matched by the previous owner, I also have a 75mm BBK tb & egr spacer, 90mm lightning maf and 03-04 cobra cold air kit. The BBK has a whine that goes away and is not the problem (I also read the BBK sticky)

I have a whine originating from the upper intake, at first we thought it was a vacuum leak. I checked for that yesterday using the carb cleaner trick didn't find anything. Using a stethescope I found the whine inside the upper intake body where all the tubes go into. I know the upper is clear of debris.
What else could be causing the whine in the upper intake? And how can I stop it?

Thanks
 
R

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the whine is probaly the BBK TB......

90mm MAF.......Why :headscratch:

or could just be turbulence from the porting......

if it running ok i wouldn't worry about it......
 

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90mm MAF because it's a 347. I have a hard time believing TB. Because when it does whine you can clearly hear it coming from the TB. The whine I'm hearing is on the drivers side.
 

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Intake gaskets on lower side, towards the lifter valley. And I have seen headgaskets do the same. More probable would be the TB
 

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I installed a gt40 intake on my motor swap the upper was port matched by the previous owner, I also have a 75mm BBK tb & egr spacer, 90mm lightning maf and 03-04 cobra cold air kit. The BBK has a whine that goes away and is not the problem (I also read the BBK sticky)

I have a whine originating from the upper intake, at first we thought it was a vacuum leak. I checked for that yesterday using the carb cleaner trick didn't find anything. Using a stethescope I found the whine inside the upper intake body where all the tubes go into. I know the upper is clear of debris.
What else could be causing the whine in the upper intake? And how can I stop it?

Thanks
I'm still going to go with Reggie on this one. The BBK throttle bodies are notorious for having a whistle or whine to them. There is nothing in the upper intake that would make that noise unless it has something to do with the porting, but that still wouldn't make much sense to me.

The noise could be getting carried to the upper intake but really coming from the TB.

Quick question about your 75mm TB... Did you make sure the TB opening on the intake was ground out to match a 75mm TB? GT40 intakes have a 70mm TB opening... :scratchchin
 

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Discussion Starter #6
<snip>
The noise could be getting carried to the upper intake but really coming from the TB.

Quick question about your 75mm TB... Did you make sure the TB opening on the intake was ground out to match a 75mm TB? GT40 intakes have a 70mm TB opening... :scratchchin
I'll look into it some more. Yes the intake has been opened already, that was one of the first things I checked before I installed it, in fact it's slightly larger than the 75mm.

-R
 

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Not every BBK throttle body will whistle (mine doesn't) but it's possible.

You say you checked for gasket leaks... was that upper to lower, or did you check the lower to the head gasket? They're really easy to move out of place when installing the lower intake. It's really common for this gasket on the drivers side to leak and cause a whine/whistle. You usually hear it when the engine is warmed up and coming to a stop or after it's revved and the rpms are coming down.
 

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Discussion Starter #9
Not every BBK throttle body will whistle (mine doesn't) but it's possible.

You say you checked for gasket leaks... was that upper to lower, or did you check the lower to the head gasket? They're really easy to move out of place when installing the lower intake. It's really common for this gasket on the drivers side to leak and cause a whine/whistle. You usually hear it when the engine is warmed up and coming to a stop or after it's revved and the rpms are coming down.
I checked the entire drivers side. Yesterday I pulled the upper to reset the rocker arms, we double checked everything and did not see anything out of the ordinary. The whine was not present when I started it up. I'll go thru the TB and see if smoothing out the AIC port does anything.
 

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Let us know the progress. It might be a broken vacuum port on the tree.
 

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Let us know the progress. It might be a broken vacuum port on the tree.
wont be the vac tree, I have a CNC'd vac tree :bigthumbsup. I'll get back just waiting for my new gaskets to arrive.
 

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Discussion Starter #12
whine is gone

Well I finally got my car working. The whine is gone; I followed the suggestiong from teh BBK thread, I also added the IAC idle plate to help dial in my idle.

I still have no clue as to what the real cause of the whine is, but I am leaning towards the BBK TB as everyone suggested. I still have a hard time believing that the whine was from the TB which is on the other side of tge engine. :headscratch: oh well the important thing is that it's gone.

Soon as I figure out the charging issue I can start tuning :happyhapp
 

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I installed a gt40 intake on my motor swap the upper was port matched by the previous owner, I also have a 75mm BBK tb & egr spacer, 90mm lightning maf and 03-04 cobra cold air kit. The BBK has a whine that goes away and is not the problem (I also read the BBK sticky)

I have a whine originating from the upper intake, at first we thought it was a vacuum leak. I checked for that yesterday using the carb cleaner trick didn't find anything. Using a stethescope I found the whine inside the upper intake body where all the tubes go into. I know the upper is clear of debris.
What else could be causing the whine in the upper intake? And how can I stop it?

Thanks


I was just reading an article on the 1993 Cobra, pg119 of The Official ford Mustang 5.0 technical Reference & Performance Handbook and it had a possible explanation for your noise.

"Two versions of the Cobra's GT-40 upper intake manifold were produced with the same part number (F3ZZ-9424-C). Early versions have a completely flat vertical surface along the left side of the casting. Late versions ( built after Feb 19, 1993 incorportae a V-shaped ridge that extends along the length of the casting in this same area. Teh ridge was adde to reduce objectionable harmonics created by incoming air in some of the early castings. During production, the acoustic characteristics of the early castings were evaluated and only the the "good" units reached the assembly line."

Perhaps a few of those Cobra GT-40 upper intakes got out and yours was one of them.
 
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