ooooquattro

I've been reading and searching till my eyes are ready to fall out and I'm not finding any other posts talking about this sort of problem.

I have a 2000 A6 avant quattro, 2.8 engine, with 250k on the clock. I have a very minor tranny fluid leak at one of the transaxles that's been there since about 100k. I top off the tranny fluid once a year and it usually takes between .25 and .5 quart to top off. In ’06 and in ’09 I did a full fluid and filter change. The tranny has always been very solid when shifting and has worked flawlessly.

This week when accelerating lightly around a corner, it thumped hard going into a gear. All week, it’s consistently getting worse and more frequent. After driving it around and experimenting with accelerating, corners and shifting, I’ve nailed down when it does this. When it goes from 2nd to 3rd, it shifts in fine, car starts to accelerate, then it comes out of gear for a second. It revs as if in neutral, then slams back into 3rd and stays there until it shifts into 4th. 3rd gear is the only one it does this with.

There are no error codes associated with this and it doesn’t go into limp mode after it happens. It still continues to drive normal and shifts through the rest of the gears fine.

The day after it did this the first time, I left it parked so I could top off the fluid that night. It was less than 1 cup low. I don’t really want to do a full fluid change since I just did it last fall and the fluid still looks decent. Not clear, but definitely not as muddy as others I’ve seen.

I’m stumped on this one and am almost ready to give up and take it in to the dealer for diagnosis. Any ideas or thoughts before I do that would be greatly appreciated.

WDeman

Hi,

I have the exact same problem except my A8 does it in 1st, 2nd and 3rd. I've also battled to find an answer. What was the diagnosis on your A6?

blockp

Bummer about the trans.

I had a couple people suggest that the valve body seals can/will just wear out after a while. Their advice; No fix but to replace the seals(rebuild trans).

Others said the tc was shot, but it didn't make sense that it worked fine in the other gears and only skipped in 3rd.

Another suggestion was a valve in the trans could be gummed up and sticking. I was hoping that was the case, so I went through another full fluid change and drove it for about 2 more months with it skipping out of 3rd. It eventually spread to 4th gear.

My end diagnosis was that the first case was probably correct (worn parts or something broke inside). My fix for it was to replace trans and tc with used ones from a scrap yard for $650. If I would have just replaced the trans and torque converter right away, I would have saved a couple hundred in fluids, but I've also seen some trans go from hardly working to working great with just a fluid and filter change. So it was worth the risk.

I had a $50 core charge from a scrap yard 150 miles away, so I dissected the trans. Just by looking and without a manual, my untrained eyes couldn't find anything obvious that was wrong with it.