A2 changing to neutral on motorway

Peeps

Got a challenge here. I have an Audi A2 tdi eco. Occasionally when driving on the motorway on a steady speed or accelerating the car will go into neutral and the accelerator will not respond. There is a strange nose on the drivers side of the engine bay. I have to stop the car.Turn off ignition and restart and
it may be ok for a little while longer. Short journeys below 30km seem ok. Initially thought it was hydraulic fluid levels. But they are ok. Did the ignition off check and got to 5th gear before the the pump started. The garage changed a gearbox oil level sensor also.
The engine bay looks spanking new with no visible leaks anywhere.
Any ideas ?

Am pulling my hair out

mark

When was the last gearbox/clutch basic setting done? Should be done every 30,000km.

RAB

Hi Rab - just had a full service. Mileage about 90000 Km.

Do you know for sure if the basic setting was done at the last or previous service? Any error codes?

RAB

Audi A2 TDi Eco

Hi Rab - the garage are taking the car in again. Is there anything specific I should ask them to check ?

Mark

I think it suggests that the clutch is slipping. I've had the same problem in the last few days with a new clutch fitted by Audi! On a German Autobahn in the fast lane (of two) overtaking HGV's - into neutral and a quick switchoff/restart. Not something I want to repeat! Yours hasn't done enough kms to be a worn clutch, I would have thought. Hopefully a basic setting will sort it out.

RAB

It might also be a poor electrical connection somewhere. I've found these fault codes since I arrived home:

00263 - Transmission
27-10 - Implausible Signal - Intermittent
00838 - Valve 3 for Gear Selection (N286)
35-10 - - - Intermittent
00839 - Valve 4 for Gear Selection (N287)
35-10 - - - Intermittent
00297 - Gearbox Speed Sensor (G38)
03-10 - No Signal - Intermittent

However, there were lots of other codes which Audi hadn't cleared after looking for a previous non-existent electrical fault. When I took the car in I told them that the clutch had seized. Because it wouldn't start they started looking for an electrical fault - a 1.2Tdi won't start with a faulty clutch. After 2 and a half hours of investigation they came to the right conclusion! Not sure how they do their basic setting (car would not start in P and would not go into 1st gear in P) but they presumably have to clear fault codes before doing a basic setting, so the above are probably relevant.

They also condemned an almost new clutch actuator (£225 worth and only been used for about five miles) and replaced it with an old one that I gave them. The new one wasn't returned with the car, so I phoned them the following morning. The actuator was rescued from the skip! I've since re-installed it and it works perfectly!

RAB

Hi Rab - my A2 is checked into the garage with your recommendations in hand - lets see what they come up with. Will keep you posted. Notice a light leak on the power steering pump possibly giving low hydraulic oil ?

Cheers

mark