veeguy

My 2001 TT Quattro suddenly started a bad vibration or rumble from the rear area of the vehicle. This started immediately after I went through a car wash, which may or may not be related. The car has 31,000 miles on it.

The noise and vibration only happens when I am turning, the tighter the turn, the worse the noise. It also happens in reverse, almost worse than in forward gears.

I assume it must be differential related, since it happens only when turning?

I want to try changing the differential fluid as a start. Must/should I use Audi/VW specific fluid or is there a standard industry lubricant that is OK?

Any thoughts or tips would be greatly appreciated!

veeguy aka Ron

Jazz

the rear will make a binding sound if it is out of toe too much.....did you drop it? i like to put oem oil in my car.

veeguy

Interestingly enough, thats why I mentioned the car wash. When exiting the wash, I ran up over the wheel guide a bit. It may have knocked the read end out of alignment. Less than 2 miles after this, the noise/vibration started. My other thought was the undercar flush may have gotten water into a connector or electrical plug?


I took it to a VW dealer here (they used to be VW and Audi, but dropped the Audi dealership 2 years ago) , and they pronounced it was a bad Haldex unit, and quoted me $3643.- to replace it! They based this on a tool called a "Chassis Ears" that locates noise under the car. They didn't do any further diagnostics. I want to do a filter/fluid change on the Haldex as a first step in troubleshooting.

Another thing, my VAG scan tool showed an error code for "Checksum error" on the AWD section, as well as "Low voltage on buss" error in the AWD section. Is this meaningful?

You have a very nice car. I have the same wheels on mine.

veeguy

Jazz

hang the car (if you can) put it in gear and see if the wheels turn together.
i would check the bushing on the rear control arms see if you have play in them.
$3600 is a lot of $$ i think i would sell it....thats like 1/3 the price of the car. as for the error codes im not sure?

my dealer told me i had a broken steering rack and it would be $2300.00 to fix.......it was the front drivers side swaybar bushing and drivers side swaybar link....lol... cost me less then $40.00

veeguy

OK, but please tell me you went out and bought new bushings, and didn't repair the old ones with -1 part rubber & 3 parts crazy glue!

Jazz

lol no, i did it all from H&R front and rear swaybars & links, EBC control arm bushings, lower ball joints, upper strut mounts....i did it all...it rides like its 1 part rubber & 3 parts crazy glue!

lol i think ive spent like 18,000ish in upgrades in the last 3 years....if you ask me i have spent too much on this car!