A8 D2 3.7 1998 Gearbox problems

[Trotskey]

Hi there,

absolute newbie to A8 cars but have been reading this and other forums due to being interested in purchasing an A8. Finally purchased a car (1998 3.7, 83000 miles or so I realised all ) two days ago, drove home 75 miles and all was good. Short 3 mile trip the next day, still good then gave it a wash and general clean up. Started the car and noticed the CAT warning light on. Disconnected the battery and checked the fuses that looked relevant in line with owners handbook (fuse carrier 4) nothing blown, re connected the battery, cat light gone so set off on a short trip. After a mile or so I noticed all gearbox lights were lit red, PRND432, it was still changing up and down the gears fine, turned round and drove home, parked and disconnected the battery. Reconnected battery and started this morning, when going into reverse or drive, a quite vicious change/thud. Have checked the black box for water ingress in line with forum website, bone dry, tested the 4 fuses in there, all good. Looked at the MAF and can see nothong untoward (though I admit it would have to be an obvious fault for me to spot something) The mileage on the car has been verified re Gov website and I believe it had been stood for a while as green moss was on parts of the trim. Could I be that unlucky that the gearbox problem has occured the day after purchase (motorway speed on journey home was legal, revs on test not over 3,000) can the gearbox fault (if it is) be hidden by a dodgy garage (no warranty on car) or could it be electrical gremlin. I have looked at getting a code reader , 2.8 and 4.2 readers seem popular but 3.7 readers on the net seem scarce? Any help is most appreciated, I knew I was taking a punt with the motor but was not expecting it this soon,

thanks,

Dave

3.bmp

[Dan3222]

Welcome to the forum. What a cool car btw even with these problems.

As far as code readers go I am sure a general OBD11 reader or such like would talk to your car. Never heard of specific ones for engine sizes but I could be wrong!

My bet is these faults where there when you bought the car and the codes had been deleted hence no warning lights for under 100 miles. 

Best bet is get the codes read correctly and deal with each one in turn. I guess the box is an automatic, this could just be low oil level. Particularly with a 'clunk' on engaging a gear. Other cause of that is commonly the solanoid for gear selection. My advice here is start the car and let it warm up for about 5 mins. The clunking should go away. Get the oil level checked somehow too.

If you bought this car from a garage you should approach them to see what they can do to assist here, less than 100miles!! Not fit for purpose! 

Best of luck with it all.

[Trotskey]

Hi Dan,

thanks for the reply, I will look at getting a cheap generic scanner and give it a go. When the car drove well on the way home it showed no signs of gearbox faults, everything smooth, tiptronic change good as whereas today if I start it and go to reverse it feels harsh, mildly violent, if foot hard on brake it is better, so unfortunately my way of thinking is a gearbox fault. I know I can change the oil though would need to source a reputable experienced garage in the Lancashire area but I think I am right in saying, after the oil change the fault may still be there so it might be £400 or whatever the price is for gearbox oil change on a car that needs a new gearbox which I gather are rare, expensive and cost more than the car is worth.  

[Magnet]

Hello Dave,

I would go with Dan's advice regarding first approaching the garage you bought it from. It has to be fit for purpose as Dan points out.

Personally, I would not do anything with it (not even plug in a code reader) until you have talked with them and notified them in writing (e mail will do) of your discontent. If you do anything, however simple, they could quite reasonably argue that you have been fiddling with it. 

If you bought it 'as scrap with all faults, whether declared or not' then ignore the above, or of course if they informed you that there was a gearbox issue with it - which I guess they didn't. 

Good luck and kind regards,

Gareth.

[Trotskey]

Hi Gareth,

thanks for the reply, cannot pursue as sold "with any faults it may have" I just borrowed a generic code reader, very basic, it showed fault P0705 which, according to the code reader manual showed it as an "automatic gearbox fault PRN1234", cleared the fault and the car reset and drove ok BUT the tiptronic will not change the gears manually so still thing there is an error here. Have disconnected the battery again, will try tomorrow to see if tiptronic is working, which I doubt.

[Trotskey]

Update on post, tiptronic came back on after about 4 days and has been fine since although my maximum journey has been approx 10 miles. Fingers crossed it may have been a glitch in the system as by the moss surrounding the outer trim etc. it seemed to have stood for a while. Here's hoping.

[Steve Q]

Let's hope it is all sorted Dave :) obviously the only way you'll know is by going on a long drive. 

Cheers

Steve :) 

[Trotskey]

Spot on Steve, just need to have my confidence restored, though it is getting better. Just took it for a M.O.T, it failed but only on a broken rear coil spring, will be sorted by Tuesday, not bad for a 19 year old car,

Dave.

[Tom_se]

My 3,7 1997 cant get any gear in, never any problems before, came home after a trip no prob, should get it in reverse nothing happens then no gears work. Need urgent help.

[Steve Q]

13 hours ago, Tom_se said:

My 3,7 1997 cant get any gear in, never any problems before, came home after a trip no prob, should get it in reverse nothing happens then no gears work. Need urgent help.

If auto even was the gearbox last serviced? 

Is the selector eliminated? 

It could be the gearbox module. 

I'd also recommend a diagnostic check to see if any fault codes flag up