Suspected Auto box failure - HELP!!!

Posted: Tue Mar 08, 2011 7:22 pm

Evening everyone,
This morning I was in South Leicestershire, now I'm in Aberdeen. After 450 miles of this 500 mile journey the following occurred at circa 70 mph (Yes really, I like my license!) on the A90 near Stonehaven:

1. Red oil light flashed for a few seconds, then stayed illuminated.
2. Rev counter needle did the fandango between 0 and 4000 for a further 10-15 seconds.
3. Acceleration pedal depressed- No effect. Slowly decelerating...
4. Began to brake, dropped the car into neutral (Auto box), blipped the throttle and back into drive. Nothing happened. Shocked

5. I saw a blue P in the distance, continued to brake and at the point at which the ECU decided it could manage it, I was thrown into second gear (Limp home mode) and cruised gently to a halt in the layby, at which point it promptly stalled. Shock

Turned off. Turned on. All symptoms gone, all temp gauges reading normally, started fine and drove the remaining 50 miles with a pit of the stomach feeling. Confused

Other environmental factors to note, I have no underside engine cover and it had begun to rain heavily about 2 minutes previously but everything else was normal.

Ironically I paid a visit to Bladerunner (Excellent chap!) this morning to get a quote on some work and some advice and he quickly hooked me up to Vag-Com and there were absolutely no faults Cool

Bloody cars.

I noticed on the remaining 50 miles that the gear changes aren't quite as 'slick' as they were before and I don't know when the ATF fluid was last changed. Since I'm in Scotland and my Haynes manual is 500 miles away, can anyone advise a part number for the transmission fluid filter, the specified fluid and the quantity required? I'll be getting onto that in the morning. It's an AAT/AEL Auto 4 speed box.

All other ideas on the possible causes of the jumpy needle and light are more than welcome and if you know someone in Aberdeen who's friendly and has Vag-Com, please let me know. I have to drive it 500 miles home a week on Friday (after it's been stood for 5 days) and I don't fancy doing that without a more concrete idea of what the hell happened and how I might be able to stop it from happening again. Brick wall

Posted: Tue Mar 08, 2011 11:12 pm

This is just a quick guess / idea, you had some electrical glitch hence the warning lights etc, and the gearbox has lost it's settings, not 100% sure on this but i think the box needs to be reset if it looses it's memory.. and I'm sure this can result in less smooth gear changes..

try to find out more...

Posted: Tue Mar 08, 2011 11:17 pm

This is what I remember discussing, not a TDI but the box maybe similar / same

http://www.audifans.net/ftopict-30691-.html

Posted: Wed Mar 09, 2011 8:07 am

That's very helpful, cheers Bladerunner. I've found a VAG specialist indy garage about 20 miles away so am going to give them a shout today and see if I can get there this evening.

When I woke up this morning it had snowed in Aberdeenshire and then frozen solid. Gear changes are significantly harsher and, if it does have several modes dependent on temperature, then it was definitely in 'Winter' this morning as getting it to change up on the dual-carriageway was very difficult.

I shall report back with any findings when I can.

Posted: Wed Mar 09, 2011 9:42 am

Not sure if this is relevant or applicable to your car but worth knowing / trying

http://www.ross-tech.com/vag-com/cars/autotrans.html

and if all this fails colour / contamination of the ATF is next step imho, although that wouldn't explain the other electrical werirdness you had along with the trans flipping out...

Posted: Wed Mar 09, 2011 12:15 pm

There is a very helpful garage near Stonehaven called FirstDrive who I'm nipping to see tonight, they are too busy to spend a great deal of time but are happy to take a look in Vag-Com and give me any fault codes. I will report back later with any findings. Huge thanks for your help on this.

The electrical issue seemed to happen too soon into the heavy rain for me to believe that it's anything other than a water ingress issue somewhere at the moment. I'll be going through the engine bay later and re-seating a lot of plugs.
Whatever it was, it isn't evident at the moment and although grumbling, the car seems to be reasonably happy and driveable. I'll get to changing the fluid later in the week/over the weekend as my offshore trip this week has been cancelled Cool

Posted: Wed Mar 09, 2011 10:13 pm

Ok, firstly a big thankyou to FirstDrive near Stonehaven, very friendly and helpful people and they ran through my fault codes without charging me.
It would appear the original issue was the speed sensor on the gearbox. The fault code indicates that it stopped sending information which could be a poor connection or water ingress as I suspected, I will be cleaning the contacts thoroughly tomorrow. I guess this is why the box went into limp-home as it thought that I had come to an abrupt halt!

Other than that, no faults reported. Gearshifts are still gritty but I removed the whole interior this evening before I drove to my hotel and it seemed a little better without the weight of all the seats. New (replacement) interior can wait until Saturday though, I found that the passenger footwell is absolutely wet through under the carpet Sad

Posted: Wed Mar 09, 2011 10:21 pm

Only time I have had a wet carpet was due to the bulk head not draining as the little tube was blocked, had my own on board swimming pool.

Posted: Wed Mar 09, 2011 11:26 pm

yep they are under the scuttle under the bonnet and can get blocked with leaf mulch... failing that does yours have a rain roof?

Posted: Thu Mar 10, 2011 7:49 am

No. I will be checking said little pipe later tonight. The foam surround below the battery compartment is sodden below it but there didn't seem to be any damp patches further up (when running my hand around anyway) to indicate where it was running from. Further investigations shall continue this evening.
I had a concern that it could have been due to a poorly replaced windscreen on Christmas eve, (thank you National Windscreens) because the seal across the top came out about 5 weeks later and had to be re-stuck with that black gunge they use. Not that that particular part is likely to be the issue but it showed signs of poor workmanship.

Gearshifts were better on the way into the office this morning although I got distracted by a very nice white M reg 2.8 Coupe that followed me up the bypass and then blitzed me after a few miles. Lovely looking motor, and in the best colour too.

Posted: Sun Mar 13, 2011 7:41 pm

So...
Having spent the weekend fitting a 'new' interior and all of the associated grief that comes with that, I found a solution to the gritty, sticky auto box that had forgotten when it should be changing gear Surprised

Obviously part of the 'why is my passenger footwell full of water' investigation involved removing the battery completely and I didn't have a PP3 to hand so the stereo kept it's memory so I just unhooked it and went about my foraging. Nothing turned up, the wet floor is still a complete mystery and I shall be keeping a close eye on it. I returned the battery to it's rightful place and proceeded to drive to the tip with a car full of old interior. I recorded the following:
Started on the first turn.
Revved smoothly all the way to the redline without sounding like it had a bad lung infection.
Pulled like it used to.
Changed gear when I expected it to, even from cold.
headbang

Nothing beats a good old-fashioned reset every now and then.......