2001 A8L - Transmission Problems

[klaidigaci]

Well as this is my first post, I'd like to say greetings to the Audizine community, I'm glad to have become a member. Now onto my reason for this post. (I apologize beforehand for the length)

In May 2015 I bought a 2001 A8L with 202k miles as my first car. It was in pretty rough shape when I got it but I've turned it around for the most part. The guy who had it before me had put in Autolite spark plugs and green coolant for God's sake... Anyway I did a regular tune-up, which consisted of a full synthetic oil change, new Bosch spark plugs, new front pads and rotors (rear were brand new), new intake and cabin air filters, took out all the small braided vacuum lines which were frayed and installed new ones, cleared out the AC evap drains, topped off all fluids, then did a meticulous detailing of the entire car. Since the day I got it there has been a slow coolant leak that I cannot locate, the warning light for low coolant comes on every 3 days or so and I have to top it off and repeat the process. 2 months after I bought it, (and 8k miles later) I noticed that it started to overheat so by doing some reading in the forums I concluded that the thermostat had gone bad. I went to my cousin's shop and proceeded to do the job myself with a new thermostat and enough G12 coolant for a coolant flush (still had green coolant) by the help of dognmonkey's tutorial.... without a cam lock bar. I also forgot to at least zip tie the cam sprockets so they wouldn't move but anyway by forgetting that, I ended up throwing the timing a tooth off. It has never been right since then, I have tried to reset the timing about 4 ties now along with the cam lock bar but the least I have got it down to is about 1/2 tooth, which is how I currently drive it until I figure out how to set the timing correctly. Another problem I have is the right rear spring which the lowermost part that sits on the rubber bushing had snapped when I did the left rear wheel bearing, so this now causes the car to sit about 1 inch lower in the right rear, and now the left front tire is starting to wear on the inside. Next problem is with the Secondary Air Injection system, almost every time the car is started the system runs for about 30 seconds and causes the engine to run extremely rough until the pump shuts off. I suspect that the kombi valves have built up carbon not only due to the age and mileage of the car, but also that I drive the car with the timing off 1/2 tooth. I'm contemplating on whether to just do an SAI delete or try to attempt to clean out the kombi valves.

And now onto the transmission.
As this was my first car I did what a normal teenager does and immediately recoded the transmission to the sport setting and started racing my friends ('03 S8 ftw), doing hard launches off the line, etc. But inevitably that wore off and I started to drive the car normally and I noticed that there was a whine while the car is in first gear, almost sounding like a supercharger whine. Shifts fine, no slip at all, but on occasion the downshifts will be just a tad rough but I think that might be due to the trans/engine mounts (front engine mount by oil cooler is shot). Scanned the car and a code came up saying "Torque Converter Clutch Stuck OFF". I raised the car up and noticed that there was some residue at the point where the driveshaft meets the transmission, so I concluded that the output shaft seal had gone bad and I was getting low on fluid which in turn causes the transmission to be jerky. But then after doing some reading on the forums I saw that the output shaft uses gear oil instead of the transmission fluid... So I'm stuck clueless. My friend's S8 transmission recently went bad on him, it went into limp mode and if he tries to drive it the trans will slip, so we're 90% sure that the torque converter is toast as he was also low on trans fluid. My A8 currently has 213k miles. Anyone have an idea what could be wrong with mine? Any help greatly appreciated!

[somedude]

Well as this is my first post, I'd like to say greetings to the Audizine community, I'm glad to have become a member. Now onto my reason for this post. (I apologize beforehand for the length)

In May 2015 I bought a 2001 A8L with 202k miles as my first car. It was in pretty rough shape when I got it but I've turned it around for the most part. The guy who had it before me had put in Autolite spark plugs and green coolant for God's sake... Anyway I did a regular tune-up, which consisted of a full synthetic oil change, new Bosch spark plugs, new front pads and rotors (rear were brand new), new intake and cabin air filters, took out all the small braided vacuum lines which were frayed and installed new ones, cleared out the AC evap drains, topped off all fluids, then did a meticulous detailing of the entire car. Since the day I got it there has been a slow coolant leak that I cannot locate, the warning light for low coolant comes on every 3 days or so and I have to top it off and repeat the process. 2 months after I bought it, (and 8k miles later) I noticed that it started to overheat so by doing some reading in the forums I concluded that the thermostat had gone bad. I went to my cousin's shop and proceeded to do the job myself with a new thermostat and enough G12 coolant for a coolant flush (still had green coolant) by the help of dognmonkey's tutorial.... without a cam lock bar. I also forgot to at least zip tie the cam sprockets so they wouldn't move but anyway by forgetting that, I ended up throwing the timing a tooth off. It has never been right since then, I have tried to reset the timing about 4 ties now along with the cam lock bar but the least I have got it down to is about 1/2 tooth, which is how I currently drive it until I figure out how to set the timing correctly. Another problem I have is the right rear spring which the lowermost part that sits on the rubber bushing had snapped when I did the left rear wheel bearing, so this now causes the car to sit about 1 inch lower in the right rear, and now the left front tire is starting to wear on the inside. Next problem is with the Secondary Air Injection system, almost every time the car is started the system runs for about 30 seconds and causes the engine to run extremely rough until the pump shuts off. I suspect that the kombi valves have built up carbon not only due to the age and mileage of the car, but also that I drive the car with the timing off 1/2 tooth. I'm contemplating on whether to just do an SAI delete or try to attempt to clean out the kombi valves.

And now onto the transmission.
As this was my first car I did what a normal teenager does and immediately recoded the transmission to the sport setting and started racing my friends ('03 S8 ftw), doing hard launches off the line, etc. But inevitably that wore off and I started to drive the car normally and I noticed that there was a whine while the car is in first gear, almost sounding like a supercharger whine. Shifts fine, no slip at all, but on occasion the downshifts will be just a tad rough but I think that might be due to the trans/engine mounts (front engine mount by oil cooler is shot). Scanned the car and a code came up saying "Torque Converter Clutch Stuck OFF". I raised the car up and noticed that there was some residue at the point where the driveshaft meets the transmission, so I concluded that the output shaft seal had gone bad and I was getting low on fluid which in turn causes the transmission to be jerky. But then after doing some reading on the forums I saw that the output shaft uses gear oil instead of the transmission fluid... So I'm stuck clueless. My friend's S8 transmission recently went bad on him, it went into limp mode and if he tries to drive it the trans will slip, so we're 90% sure that the torque converter is toast as he was also low on trans fluid. My A8 currently has 213k miles. Anyone have an idea what could be wrong with mine? Any help greatly appreciated!

you have a lot going on here. I will help you where I can but for now I am going to only touch on the timing and the transmission. You need to get the proper timing bar and set the timing properly. The mark and prey method is just not the correct way to do things even though it can sometimes work. ECS tuning sells them and the process is very easy. Writeups are all over on how to set timing so I will not get into that.

TC clutch stuck off is almost always a bad converter AND and valvebody in need of repair. If you have an advanced level of skill you can repair the valvebody, however if you have a average tech skill I would send it out for rebuild and replace the converter. In some cases it is possible to flush the fluid out and you can drive it for a very ling time without TC lockup but your fuel economy will take a bit hit and your trans temps will forever be high. The reason for flushing the fluid out is that your converter will be pumping burned up clutch material into your trans and that will usually cause other failures if the fluid is not kept clean. This is a bandaid and is not the proper way to go about it. It may be more cost effective to install a used transmission and converter.

[somedude]

We have a 00 A8 with also with a transmission lockup. When we set the car in reverse it doesn't have any problems at all, however when we put it into drive the gear selector display lights up and the car is reluctant to start. Giving it a bit of gas and around 1500 - 2000 rpm it gives a small push and then it starts going. It is clear the car doesn't start in 1st. gear, but more like 3th. gear. Once in motion you can fell anything wrong only that it doesn't accellerate as normally. There are no strange noises or sounds comming from the gearbox.
Any one know what could be the problem and perhaps know how to solve it?

in my experience your transmission is dead. I have a trans that was replaced at the shop with the same symptoms in my garage waiting to be dismantled.