Putting together the S6 after carbon cleaning and installation of spacers. Car starts and runs, however have a loud whistle sound, it’s rpm dependent, and if I put pressure on the throttle body it will change pitch. Assuming I have a leak between throttle body and intake. Removed throttle body, checked new gasket and mating surfaces and all appears to be good. Reinstalled and torqued to 9 NM and one bolt broke before getting to the 9 nm. These appear to aluminum bolts, getting some new ones tomorrow. Anyone else have this problem? Looks like you need to be very carful with the torque spec.
Anyone use a sealant in addition to the gasket? Is warping a possibility? Put a straight edge on the throttle body flange face, and it seem pretty good, probably need a large flat surface to really check properly.
From seeing the design and working on several of them. The thing I have seen is the entire upper half of the inlet system throttle body and upper intake can be a big fight.
With the throttle body you shouldnt have had to take them off to do the carbon clean. If you did you would have to clean off the serface and really take some time to slowly tighten them back down. You would have to go and tighten the bolts down in a X fashion working on the top right and bottom left and then the top left and bottom right. Slowly working your way up to 8lbs
The other point that can leak really easy is the plastic elbow that comes from the air box. That can be a big pain. What I would suggest is getting a bottle of starter fluid and spaying it around to find exactly where the nosie was comming from.
Didn’t remove the actual throttle bodies, was just calling the upper intake “the throttle body”. Getting the replacement set of bolts tomorrow and will try again. Will inspect those elbows, when I grabbed the drivers side it changed pitch, however I thought I was moving the upper intake. I’ll try to post the video.
Thanks!
Ok what you mentioned I have seen in person. Yes that old gasket seems to be a one time use gasket and I would order another one. Even adding a little permatex sealent around the flange is a good idea.
I would start with the bolts only that attach to the lip of the intake and not the bolts that attach to the top of the intake. Slowly work those flange bolts in the same kinda cross fashion as you would the throtle bodys or the actual intake it self
I used a new gasket and cleaned all the mating surfaces. Removed inspected and retorqued, that’s when I ran into the bolt problem. Here’s a short vid of the noise, its loud!
I realize that the air intake tube clamp was loose, it made the sound when tightened as well.
Found the problem, didn’t reinstall the bracket for the oil separator, and had removed the two bolts from the throttle body that held it in place, DUH! Bracket installed, bolts torqued, whistle gone.
Thanks for the update. Its always so helpful when people come back and follow up. It gives others a chance to read how you solved the issue and that can give them one more thing to look for.
Great to hear you got this solved!
I’ve got a weak/cracked throttle body mount (top left) that area was stripped and had air leaking through post MAF - had terrible rough idle issues. RTV + a longer bolt and backing nut has fixed it for now. Looks like the mounting location is weathered and brittle from heat cycles over the years… shouldn’t really be the case though.
Your right that shouldnt be an issue. Any chance you can take a pic and show whats going on. Maybe that will help others see what to avoid or what we can do to help suggest on what else you might be able to do. Any chance this might have something to do with some of the other issues you mentioned in the other thread