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View Full Version : 2000 A4 5 speed tiptronic torque converter issues...?



Baci
02-03-2019, 07:58 PM
I just got done doing some work on my 1.8 (b5 a4 2WD 5 speed) and just gonna ask if any of yíall have experienced this issue to save some time trouble shooting, as I couldnít find anything especially relevant anywhere else.

On occasion, the car gives a sensation similar to the torque converter failing to unlock, nearly stalling the engine, and shortly after going into neutral before slamming back into gear. Other times, it feels like the torque converter unlocks (the car still is able to accelerate, but the revs are erratic) and slams back at random, however whenever the car hits a moderately sized bump it happens almost 100% of the time.

Also, when in gear, most of the time the car surges pretty harshly at a stop, which I think may also be a torque converter issue.

Part of the service I just did included new atf, however there wasnít much of a change in symptoms. The producere I followed was to fill from the fill plug until it drips out, then let the car run for a while, and cycling through the gears, then refilling until it spills out again, then torquing the fill plug, and I did clean out the pan.

I havenít been able to pull any transmission codes, however Iíve only checked with my hand-held and not my laptop. I heard that on occasion the connector for the shift solenoid can come loose, or the solenoid itself can go bad. Has this been known to cause these symptoms?

The car upshifts smoothly and downshifts a little roughly, but otherwise itís normal.

Cybersombosis
02-04-2019, 12:55 AM
A faulty TCM? It is located in a plastic box under the front passenger floor carpet. It is prone to pooling water in this spot if there is a leak in the sunroof and will flood the unit causing irratic behaviour. If you unplug the TCM, it should go into limp mode and drive in second gear. Does it behave the same while accelerating with the TCM unplugged while in limp mode?

Doug

walky_talky20
02-04-2019, 09:01 AM
I have a somewhat similar issue with my B5 Passat 1.8T FWD Tiptronic. But mostly in Reverse. Selecting Reverse works fine, but it will sort of fall out of gear (stop creeping backward) then slam back in all at once. 1st gear seems mildly affected, but only on very hard acceleration.

My solution: 5MT swap it like it's hot.

PZ.
02-08-2019, 12:56 PM
If you are local, I can scan with VCDS and I also have a free used TC that should fit.

Joe Jr.
02-08-2019, 02:30 PM
I hate to be be a negative Nancy but the tiptronics are ticking time bombs. Not saying i'm an expert on the transmission but i've had 2 of them and unloaded the cars because of the transmission. Anyways, look at the step at the end of this tech article about running the car through the gears when adding the new fluid.

Looks like you did that, so you should be good. just verifying.

https://www.blauparts.com/audi/audi_fluid/audi_automatic_transmission_fluid.shtml#audiautoma tictransmissionfluidinfo

Baci
02-08-2019, 10:33 PM
Some quick updates: the surging Under load I described turned out to be caused by a defective fuel pressure regulator. I had a lean code and pulled the vacuum line and to my surprise the surging almost completely disappeared.

However, the transmission still gives the impression it goes into neutral anytime the car hits a bump, a moderately tight turn is taken, or under sudden braking. Because this only happens when the car experiences an acceleration could it indicate some wiring issues or a solenoid issue? Possibly even the fluid level?

Thanks for your replies.

Cybersombosis
02-08-2019, 11:40 PM
Just double checking but when you filled the fluid, you had the car running right?

Doug

Baci
02-14-2019, 07:10 PM
I did not. I wasnít following an official procedure, and if it was listed, I completely missed it. I added until the pan was max capacity, then let the car run for quite a while, and ran through all the gears. Afterward, I immediately filled the pan to max capacity again and closed the system.

From this point, would it be appropriate to re-top off the transmission while the car is running?

I just had to pull the radiator out, so I may have to add some anyway.

Cybersombosis
02-14-2019, 09:26 PM
I think that is your issue. The system isnít full. You have to fill it with the car running on jack stands and level. With the car running, let it get up to operating temperature. I waited 5-8 minutes. Fill until fluid spills out then get in the car. With your foot on the brake, run through each gear for 30 seconds, down, then up, 30 seconds each. DO NOT turn the car off. Get out of the car and fill again until it spills out. Run through the gears one more time like before. Fill one more time until it spills then button it up. This is all done while the car is running. Do not turn the car off or all the fluid will spill out. Hopefully this solves your problem.

Doug

PZ.
02-15-2019, 07:20 PM
Since you are in TX, as soon as you run the trans through the gears it will already be at or above the correct temp. If the pan feels slightly warm, it's warm enough to fill and close the plug.

walky_talky20
02-20-2019, 07:33 AM
^This.

You really don't need to worry about the temp thing, as long as you fill it when the trans is cold. By the time you have it topped off, you will be at or near the correct temp. Even if it's not up to "spec temp" yet, letting it warm up to the exact temp will only push out on the order of a few ounces of fluid, if that. Negligible amount. So just fill it cold and don't take forever to do it and you'll be just fine. You may be an ounce or two overfull, no worries.

Baci
02-24-2019, 04:17 PM
Finally got around to topping it off.
I did it after my drive home from work, and did it while the car was running this time. Sure enough, that did the trick. I drove around for about 20 miles and it feels brand new! What a goofy mistake on my part. Thanks for the help.

Cybersombosis
02-24-2019, 05:10 PM
Glad it was just s simple error. Imagine taking it in to the shop and getting raped with a $400 bill? That would have happened if you brought it into a shop at the very least. Or worse yet, them telling you it needs a new tranny. Glad it worked out!!!

Doug

Blazius
02-24-2019, 05:24 PM
Glad it was just s simple error. Imagine taking it in to the shop and getting raped with a $400 bill? That would have happened if you brought it into a shop at the very least. Or worse yet, them telling you it needs a new tranny. Glad it worked out!!!

Doug

Well to be completely honest , should really do manual swap, tiptronic is a ticking timebomb - like walky said - and in europe you can get a manual 5 speed for less than 100 euros :)