I was driving my 00 S4 the other night and when I parked it in the garage I heard a loud whistle noise from the under the hood. I took a look and my TTB had a small leak in it. It makes noise where boost is escaping at ideal, but you can not hear it when you drive. Will this hurt the car in any way. I am going to purchase a new TTB tomorrow.

Also I was driving last night and I was in 6th gear cruising aroung 55 mph, I did not have the radio on and the widnows where up. I noticed at 1/8-1/4 throttle there was a sound coming from the motor. The dentist drill like noise that nobody wants to hear. When I give it full throttle I can not hear it. The turbos seem to be spooling fine. Seems like I am getting full boost when i accelerate, but i do not have a boost guage to be 100% sure. You can not hear the drill like noise at full throttle. Sign of bad turbo or something to do with the TTB?

 

First thing about the Tbb.

-I wouldnt drive the car with a leak or tear on the TBB as in can lead to damaging the turbos over time.
-If your tbb has a leak you should be able to tell if your car is accerlating slower than normal or you hear excessive air noise from under the hood.

2.) about the turbos.

-If you hear a dentist drill like noise and its loud during the lower rpms (i beleive from 2k-4k) it could be a blown turbo. Only way to be completely sure is have it looked at.

 

What is the sensor on the TTB? Is it safe to disconnect it?

 

yes it is fine to remove and set it aside when replacing the TBB. Just replace your TBB with a SAMCO one or APR Bi-pipe.

 

I just back from taking a drive. I have noticed for awhile that when I am driving through my nieghborhood approx. 20mph in 3rd gear, The transmission whines alittle, just in 3rd. Could that whine (drill sound) be coming from the transmission? I do not think one of the turbos are blown, They sound, spool as normal and boost feels the same. Low tranny fluid??? I whine is not relatively loud. Quiet enough that if you where not listening for it you might not hear it.

 

if the whine sound isnt that loud that you cant notice it unless you listen to it then it is definantly not a blown turbo.

Im not to familiar with the tranny or the fluid being low as i have never came across that problem. But maybe someone else on the forums definantly knows.

 

It dosnt sound like you have a blown turbo to me. Our turbos and all turbos for that matter make a spooling/wistleing sound before you hit full boost. When the cars cold it can be a little louder but its still normal. WHen the turbo is blown you should not be questioning it. Its more of a screaming babies very loud obnoxious wine most of the time theres large ammounts of smoke coming from the exhaust

Do fix the boost leak though

 

The turbos are good I had them checked out. As far as the throttle body boot, it is still good. I could not fins a pin hole or a tear, nothing. When I was re-installing the ttb, I came across a loose bolt on the Throttle body. I checked the others, they where all loose? So I torqued them down and now everything is fine. That whre my leak was coming from.