auctionjunkie

Hello. I purchased an 02 Audi Allroad 2.7T Quattro with 92k mi from the dealer auction. After driving it about 100 miles, the CEL came on, at first, I pulled a code for the catalytic converter P0431, I turned that off and drove it for about 30 miles, then code P0741 popped up, and it's recurring.

The seller is some junkyard in So Cal, the previous owner probably got scared to death by a mechanic's quote and sold it to the yard and the yard took it straight to the auction (just a guess).

Question: Would you bother with the transmission fluid/filter/gasket change or just take it back to the auction? I've done a lot of reading, and a lot of people seem convinced that I'll more than likely have a worn out seal inside the converter and the problem will return.

The vehicle looks like a million bucks, never wrecked, no oxidation, ridiculously clean. Although there is an exhaust leak or possible problem with the driver's side converter/o2 sensor, and a rough gear shift here and there, the vehicle is otherwise fantastic... I do notice a lack of power in low gears, intermittently, that's why I'm thinking low transmission fluid or clogged filter/valve body.

To me, it's a tough call... the last thing I want to do is spend $200 (my cost for 6 quarts of audi trans fluid.. filter and gasket) only to sell the car and have the customer return with a CEL... curious to hear your feedback .. thanks...

raj99

Certainly could be a stuck solenoid, but if it's as good as you say it is, why the heck not spend the $200 and get the tranny fluid changed, since it's most likely long overdue. If it fixes things...well you win. If not, then your $200 poorer and you sell it back at the auction...a $200 gamble isn't a heck of a lot.

auctionjunkie

i hear you, raj. is the tc solenoid something i can clean or examine from the bottom of the pan, or does the tc need to be pulled?

auctionjunkie

I have the car on 4 ramps... when shifting through gears during refill, the wheels don't need to be spinning, do they? I thought someone said the wheels have to be free spinning as you cycle through gears...

thanks

auctionjunkie

never mind.. found the answer here

raj99

Glad you got it figured out and also for future reference here's the actual SoP for doing the work: http://www.zf.com/media/media/docume...hselkit_EN.pdf

Let us know how it all turns out.

auctionjunkie

rolling the vehicle up on 4 ramps on level 4 is the easiest way to work on it. I think that was the only thing I got right the first time. I couldn't find a torque wrench that dialed down to 10 nm for the tranny pan bolts, so I tightened them "by feel"... bad idea.. more on this later...

Didn't wait until 35-45 degrees C before pumping in fluid.. I got about 6 quarts out and over 6 liters into the transmission.

My initial test drive went as smooth as silk, drove the vehicle on the freeway for about 50 miles... gunned it up a steep hill until I hit 80, torque converter kicked in and rpm's dropped...

The next day, it drove fine on the freeway for another 30 miles, then I parked it at the gas station, turned it over, and noticed that the engine temp was past the midway point... it felt a little sluggish in 1st gear, then the CEL came on... ughhh ... p0741 back like jason

I roll it back on the ramp and notice that some of the pan bolts were coming loose, and it has lost some transmission oil... I bought a torque wrench that dialed down to 10 foot pounds (which I know is too tight)... but I rolled with it, tightened all the bolts to 10 ft pounds.. stripped another bolt, my third one (2 stripped during removal process)... btw, for those who are interested, I drilled the bolts about 1/2 inch down the center with the correct sized titanium coated drill bit and hammered a square screw extractor about 1/2 inch into the screw and it twisted right out. Bought the square extractor set from Oreilly's, way way way better than those "grab-it" type extractors, imo.

Warmed trans up to 30C, went through all the gears, removed fill plug, no drip... as soon as i rip open a fresh $16.50 bottle of transmission fluid, I look at the fill hole and it's streaming with fluid... I waited until 40C until fluid was just dripping out and torqued the fill plug to 35 nm.

re temp: I saw a ZF tutorial on youtube which was awesome, it said to check for the proper fill level and fill between 30-40C, the local Audi dealer said 35-45... I tend to go along with ZF's advice.

Going to pop in the new bolt tomorrow and go for a test drive. No pan leak, so far. What I've learned is that it isn't hard to do this, but this job has to be done with precision and the right torque wrench.

When I performed the initial drain, the fluid was black, so keeping fingers crossed...

Question: would the loose pan bolts contribute to the P0741? I'm assuming that optimal pressure wouldn't be achieved to allow for proper fluid circulation.

Will post results after all monitors are checked and the vehicle has been driven 200 miles.

auctionjunkie

cel came on after about 50 miles, same code. checked the trans oil level at the correct temperature, it was overfilled... drained about 1/2 liter of extra fluid from transmission, will test drive it again... not holding my breath...

the transmission seems to shift just fine, it'll probably go back to the auction.. on to the next deal ...

Rhino14

Curious if you have any updates?

cameltrophyallroad

That code was thrown by my 01 a few years back, mechanic stated it was mandatory to change out the TC since the early cars had bad ones or the Tranny would suffer. I did, then did the tranny anyway 40k miles down the road. If i had to do it over again i would have just done the whole program, tranny & TQ. unlikely it'll clear itself with a tranny flush, sounds like you're best taking it back to the auction. Or what i should have done was just do a 6mt and be done.