so i bought this 03 passat with a 2.8 v6,automatic tranny with a broken timing belt. replaced the heads t belt idlers etc. car runs great except the tranny hunts and ocassionally thumps down into first gear when coming to a stop. the car has only 60,000 miles. here are my thoughts, does anyone else ever notice how much vw/audi uses there torque converter in the modulating stages? bmw and mercedes dont do this nearly as much. and bmw and mercedes dont seem to have these problems with the same transmissions! ( i know mercedes uses their own) it is my strong opinion that all of this modulating leads to premature wear of the torque converter clutch. now hear me out i understand that the clutch is still strong enough to "hold" but i think what causes the hunting is the clutch can no longer "slip" correctly. when the tcm is "modulating" the torque converter clutch it has to apply it so far that it locks up. the tcm then sees this through the speed sensors and unlocks it in an attempt to modulate it rather than lock it. when the tcc wears out it becomes an all or nothing type of clutch and the computer doesnt like that. i did a lot of searching on iatn which is a website for automotive technicians like us and about 9 people have replaced torque converters on these older a8's and fixed their problem. now i know paul had his rebuilt and his still hunts. from what i understand you can NOT rebuild these torque converters. i will be replacing the torque converter in this car and will let everyone know the results. oh and by the way lets not forget that fluid pressure DISengages the clutch and a spring inside the toque converter ENgages the clutch. the tcm is trying to continuosly find that perfect slip rate which results in the hunting. feel free to post your comments.

 

my '06 got a new VB at 11,000 miles

 

was this for the same symptom angus?

 

i am just amazed how vw/audi can have problems with anything!! there is not one component on these cars that didnt have problems with a certain year/model. i gotta say bmw and mercedes have problems too but they sure dont seem as major or frequesnt as ours. and yes i have worked for both and yet i still own 3 audis? well i guess its a love affair. trash trash trash

 

it started slipping on the 1-2 shift and then slamming the shift so hard it would chirp the tires

 

i think mine was just a fluke, its been perfect since then

 

my wife's 04 Passat V6 4-motion hunted a little and wound "thump" hard in to 1st gear with an abrupt stop. After dealing with this for a while, VW released a flash update for the tcu. It can be seen in the VAG adaption code as a new number.

Please note that this hunting and thumping to 1st gear were a lot more drastic than what my A8 did. BTW ...... mine was replaced by the dealer under CPO at 52,000 miles. I'm now at 114,000 and 0 hunting or thumping at all. ***knockin' on wood***

 

I agree with muuch or your position.
Uncompensated wear could be the problem

Questions remain.

What change occurs when a transmission Control unit is reset?
Some say it may be fluid line pressure, but there is no suggestion of that through the logging of Valve activity. (I could have missed something in my own efforts.

What is the limiting aspect that keeps the N218 solenoid PWM current from achieving a broader range of control values?

These are of interest, but if a new TC will do the trick? Hey that will be good news.

I wait to hear.

CalG

 

i appreciate the info. thanks!

 

i will keep you posted calg i appreciate youre insight. however i will be checking for that tcm reflash as theraudi suggested. i am bound determined to figure this out and i am gald you are too. thanks!