Lost all drive
 

My S8 had been parked up for 13 or so days without starting the engine, then I went on a 500 mile round trip journey. Today started the car, and was driving down the Fosse way. Came to a roundabout and started to speed up again. The revs suddenly went to 7k and the speed didn't increase. It was like I was pressing the accelerator in neutral. Happened again a few times then PRND432 all lit up in red, and the car went into limp mode. It struggled to drive down my girlfriends driveway and then I turned it off, started the car again, put it in D to drive forward and a big thud and the cars rolled back slightly, all box lights on again. Didn't have my Vag Com on me so can't test. I'm waiting for AVP to open on Monday so I can sort something out with Ben or get him to come out then get it flat bedded to him to see if its something simple such as a drive shaft/maf. He's the only person whos judgement I really trust. Fingers crossed but doubt its a maf, drive shaft is possible. I have an AA warranty which covers me upto £500 which should help out, just a bit.

Could someone point out my options for me please?

Comments will be very much appreciated. :(:(:(:(:(:(:(

I don't like the sound of this Amar, as it could be the dreaded transmission....

Yep Clive, I think it is but I did have an A8 that lost all drive and it was a driveshaft. What happened in that was it just went bam, a lot of noise and no drive, it revved loads in D similair to this without going anywhere. Its strange but even if one driveshaft goes the whole car doesn't move. Being a quattro I thought I'd still have 3 wheel drive :rolleyes:

Drive shaft going shouldnt cause the gearbox lights to light up - Thats coming from the TCU, which in turn is either a TCU or a gearbox problem.

The big thuds might be the box slamming itself into 3rd gear (limp mode) which is 'normal' when something isnt right, if that makes sense...

Vagcom wont tell you a great deal either as the gearbox is one big dumb lump of metal with only 2 sensors on it from memory, so as soon as the output shaft isnt spinning at the speed it should be for the speed of the input shaft, it kind of gets upset and goes into limp mode... Thats my basic understanding anyway. This could happen if it fails to select the correct gear which could be anything from low fluid through to a failed clutch assembly...

Im sad to say, but it doesnt sound like a simple fix this one, but I would be happy to be proven wrong.... :(

Thanks for your thoughts Ian, I agree with everything you have said. I think it only really makes sense to go for a reconditioned gearbox, or a low miler one if I can find it, would you know what type/part number I need Ian so I can search on Ebay.de. A manual conversion could be nice, will have to see what Ben thinks...

Does it still pick up reverse? That would rule out the driveshaft.

From memory, there are a number of 'clutch basket' failures on QuattroWorld which sound like similar symptoms - TozoM8 is your gearbox man, might be worth getting his opinion. From the sounds of it, he's been in more '8 gearboxes than I've had hot dinners and he's converted his to manual.

Thanks Psyche, I am speaking with Tozo already. He reckons its the clutch which is a 220 Euro part from Audi, but its inside the gearbox so it will need to come out for a rebuild... I was able to select reverse so yeah its probably the clutch. I will have to see what Ben thinks on Monday/Tuesday and will keep all updated.

Lets hope its a TCU, never heard of a TCU failing though? But I hear there a ten min job to swap over. Would the TCU show up on VAG COM?

http://i665.photobucket.com/albums/v...S8/photo23.jpg

Hope it's an easy fix Amar, but if not don't forgot the guys at Chester Autos, they know these boxes inside out +++

I can just picture it now...

You rattling up the motorway in reverse to AVP :)

Well when I tested the reverse gear, the drive gear was working too. Its only after I started it again after I had parked it up for 15 or so mins it didn't go forward but then again it is a very steep drive, I didn't test reverse for the second time after it had been parked up. It may still work in Drive actually but when I heard the thud I got scared and turned it off.

I reckon if I disconnect the battery for a while that will take it out of limp mode, but limp mode is there for a reason I suppose. The cars 12 miles away so I can't go out and test again.