A/T bang
 

Hi all! I have a problem with my tiptronic transmission (A6 2.8l 1998). It runs fine but sometimes (it is rare, but scary when happens) when I accelerate fast and the transmission needs to reduce 1 gear (4 to 3 for instance; I'm not sure if it's related to a specific gear) the transmission does a big "bang" like if something was preventing the gear to engage and suddenly it goes in. What could this be? Is it serious or a change of fluid and filter will solve the problem?

Pull and post codes, check fluid level.

Hi! I'm waiting the hex bit to check oil level and VAG-COM to arrive. But I found something I would like you to help me with.
Looking under the car, I noticed some oil on the transmission pan. It is like brake fluid, no odor and no color. Not like engine oil. Also, I noticed that some of the hex screws that fix the pan are filled with this oil. I mean, the hex hole in the screw head are filled with oil. I guess this oil can not come from somewhere at the top of the engine (like the breaks) since there are walls around the screws. Anything coming from the top would not reach the screws. Is this assumption correct? So I can only imagine this oil is coming from the screw gasket/pan gasket. Am I right? Is it a common problem? If this is the case, the oil level shoul be low! And can a low oil level cause the problem I described (transmission thump/bang when changing sometimes)? In this case I'll order an oil change kit right now! Thank you guys again!!!! P.S.: I have 60K miles on it.

Yes. Low level can definitely cause this. Changing the oil is a good idea anyway. Make sure you get the kit that comes with the refill pump and filter.

OK! Thank you! I cleaned everything and gave a ride to heat up the fluid. If tomorrow or after I find more oil around the pan, bingo!
I'm ordering a new kit. Thanks a lot!

BTW, if the transmission gasket is made of the same quality material of the valve cover gasket.... omG, it explains everyting...

Hi! Tried to check fluid level. Removed the 17mm hex cap to check level.
While I was out searching for a mirror and some stick to insert in the check window, the oil leaked trought the cap hole! I lost about 1/2 liter of fluid. Is it supposed to happen?? As far as I know, the oil sould be at the level of the check windows so it should not leak. Especially if it is low. And, for an obvious reason, it's impossobile to put more oil than the level of the window. So how can it leak? Whan can it be? I replaced the cap as fast as I could and didn't check the level. I still can't understand what happend.... Can the tube with the check windows be loose and leaking at it's botton? Please help. Should I try again? How?? Thanks!!!

Was the engine running? If no, level is extremely low.

You are low on fluid. Likely someone pulled the wrong drainplug when changing the oil. Continued abuse will cause the transmission pump to fail, and your car will pee fluid all over the ground, effectively stopping travel.

Good luck.

Ok guys many thanks!!! You may laugh now... but jus a little. I figured out what happened. I turned the engine off to search some stick and forgot the cap was out... But the funny part ends here. I repeated the test, this time with the engine running to fill the TC, etc and inserting a stick in "U" shape I could not get even the tip wet... Wow, this is bad. I'll buy a trans kit form blauparts but as an emergency measure, tomorow I'll get one bottle form the stealer. 3X more expensive but better the riding with low fluid. I guess I can complete the fluid with one litre and drive like an old lady until the baluparts kit arrive, right?
But anyway, even considering the fluid I left out it was not enough to drop the level so bad. The good part is that now I can be sure that the oil I foung around the bolts (first post) is exactly the same inside the tranny. So, I realy have a leaking gasket. Is it common with the ZF tranny? I'm confident that if I replace the gasket and fill up with the fluid my "thumping" problem will be solved. Or it's to soon to be happy? Thanks guys! I hope some day I can help you as well.

How about not driving the car? If it was my car I wouldn't roll the dice like that.