Ok, this may take a second to get all the info across so bear with me a moment. This past weekend I began doing some routine maintenance on my Audi TT. Just purchased it, so I’m getting everything off to a fresh start on all my maintenence. So after finishing a rear brake pad job, fuel filter replacement, throttle body cleaning, Haldex oil change, and motor oil and filter change, I lower the car and take it for a test drive. This is when the front right wheel began developing an absolutely horrible screeching metal grinding noise from the passenger side front wheel. It is this wheel, with absolute certainty, had a friend drive the car as I ran alongside it. I had the wheel off the day before and noticed that the Phillips head screw that holds the rotor to the wheel hub is missing. Was still able to hold that on with the wheel bolts. So, I check out the wheel, jack it up and I notice that the lugs are under torqued. I checked for rubbing, couldn’t see anything. I checked for play, maybe a mm at the tire edge with the wheel on at 3 and 9.
More on the sound. Alternates between two sounds. One very loud screeching metal on metal noise (imagine the sound of a braking train) and the other is a slightly lower pitched noise more akin to grinding without the feel of it in the wheel or pedals, but still a little higher. I can generally induce the second noise by turning the wheel hard left, and stop it by a nudge right. However, the sounds are generally independent of anything I do. They do not seem to change pitch at speed, nor do they seem periodic, they are either constant or waxing or wanning. It does seem to happen more at low speeds, up to 10 MPH, and happens generally unpredictably. Application of brakes neither starts, nor stops the noise. Sometimes it’s there, sometimes everything is smooth and quiet. I’m thinking something is up with the pads or caliper. On the other hand, I’m thinking it could be the bearing, but there doesn’t seem to be enough play in that for this to be the case. I’m taking the caliper off tomorrow, and I’ll post back if I figure anything out but has anyone heard of anything like this? I have recordings of both sounds if anyone would like to hear them, I can email them. I’m just looking for some help with diagnosis here since I can’t reproduce the sound with the car jacked up and the wheel on or off and rotating or not. Any help is greatly appreciated! Thanks!
Forgot to mention. There is no pull in any direction, nor can I feel anything through any of the pedals or steering wheel. The other sound is less like grinding like I said, but still a screeching sound, just seems an office lower. No smooth transition between the two, it’s just one or the other or no sound and normal.
Check the dust plate behind the brakedisc. If it is touching the disc, it can make all kinds of noise.
I will double check that tomorrow. It looked good when I checked it out earlier today. I’ll be removing the caliper and rotor tomorrow, so it will be pretty easy to see.
Does The 225hp Audi TT Quatro Have A Particular Model-Year Designation ?
CSA
I’m not sure what you mean. It’s a 2001 Audi TT, that’s the full name, there was an S line model that year, and a ragtop roadster, Quattro AWD, and 225 HP engine were all options for that year. I’m not sure what my engine code is, but I’m sure I could find out if it would help. I’m heading out to take off the caliper and rotor now.
Here are recordings of the sounds the car makes. They are much louder than they seem in these short videos. I had to record them inside the car, but if you ignore the video and listen for the sound you will know exactly what I’m listening to.
Take it apart…that noise is going to leave a mark…
Success! I’ve found the culprit. Below you see both the record, and the needle. It’s too bad the sound it makes couldn’t have been more pleasant. I’ll have to look into getting Vivaldi’s Four Seasons carved into my next set of rotors…
And it did… dust cover rubbing the rotor. What a noise.
After another day of driving, what I couldn’t see in my first investigation yesterday became pretty obvious. It was the dust cover on the rotor. It hadn’t really left a mark on the rotor last time, but today when I got the rotor off I could see the mark clearly, and it was pretty easy to look at the dust cover and figure out where the mark was coming from. I posted pictures below. Thanks for the hint, it was the first thing I checked after I removed the rotor.
So what was scraping on the disc?
There was a spot on the dust cover rubbing on the rotor. You can see it in the image file I called the needle. I reinstalled the rotor to check it out and the worn spot on the dust cover matched up exactly with the ring on the rotor.