RS Grill and Intercooler

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03-06-2024, 09:51 AM

#31

stash64

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Originally Posted by stash64

Update on CTS Charge Pipe:
Don't know why, but now I am getting an unusual intake noise that is somewhat obnoxious. It is hard to describe but very obvious and is something between a whine and a moan while accelerating and it is not pleasant from the inside of the car. I did not notice this sound the first couple times I drove the Q5 after changing out the intercooler and charge pipe, but it may be because I was taking it easy on the accelerator while trying to listen for intake noise. I do also have turbo muffler delete but I know that is not the main cause of the unpleasant sound because I made that swap several months before the intercooler and charge pipe swap.
I will give it a little more time but I am glad I hung on to the stock charge pipe with resonator. It may be going back in. I guess Audi engineers had good reason to design in the resonator on the charge pipe. I was planning on a single stage tune this Spring/Summer, so I may wait to see how that works out before swapping the stock charge pipe back in. I'm guessing a tune would result in even more noise but maybe not.

Sorry... Another update. Please ignore above regarding after-market charge pipe. I decided to take a look at all of my intercooler hose joints before swapping back in the OE charge pipe and, sure enough, the hose from the intercooler was loose where it connects up to the charge pipe. The hose was still on the charge pipe but it had obviously backed off almost an inch. I could tell because I used a little bit of silicone lube and I could see the lube exposed on the pipe. The hose was also cockeyed. After reseating the hose and tightening up all the clamps, no more obnoxious whining sound when accelerating. I should have known something was amiss because the intake sound was fine for the first couple weeks. Again, I think it now sounds a bit better than stock. It is still surprising that the little turbo produced enough pressure to cause a leak at the charge pipe joint.
So perhaps using lube to help slip on the hoses is not a good idea, though I tried to apply a very light coating on the metal tubes. Also wondering if the T-bolt clamps are not the best option because I don't get the same torque resistance compared to the cheap worm gear clamps. The T-bolt clamps are just too easy to tighten and I don't get a good sense as to when I should stop. Should I be using a torque 🔧 for the hose clamps? And where would I find a good torque spec for various size T-bolt clamps? Here is one of the clamps I used:

Amazon

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03-06-2024, 01:29 PM

#32

SMac770

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Audi quotes the hoses "Must be free of oil and grease before installing". The hose clamps torque spec is 5.5 Nm. But that's stock clamps on stock materials. For alternative materials, no idea.

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03-06-2024, 02:13 PM

#33

stash64

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Quote:

Originally Posted by SMac770

Audi quotes the hoses "Must be free of oil and grease before installing". The hose clamps torque spec is 5.5 Nm. But that's stock clamps on stock materials. For alternative materials, no idea.

If the whiny noise returns again, I will clean off all the silicone and re-install the hoses. I am able to access all the hose joints easily enough by removing the lower plastic shield and the two fog light grills. I thought the silicone lube might actually help with sealing where the metal tube is somewhat of a rough surface as is the case with the CTS charge pipe, but that assumes the hose is not slipping.
On the clamp torque, I agree that it is a bit of a guess given the different clamp sizes and different hose and tube materials.

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