cliffcoggin

I'd say the problem is electrical, so I suggest you get the battery and alternator tested professionally as a first step. It doesn't matter what voltage you measure, the battery may still be defective enough to interfere with the ignition system.

Thank you. I hadn't heard of that one.

It looks like a Torx fastener. They come in a range of metric sizes and are available at most tool merchants.

Thanks for letting us know. I shall lock this topic to avoid it being revived in the future.

What's that?

Wouldn't the simplest solution be to ask an Audi dealer?

If I had not seen the picture I would not have believed six bolts could shear off. Thanks for letting us know.

Please do.

If all else fails you could weld a nut/bar/socket on the locking nut in order to remove it. Of course that will ruin the locking nut and you would need to buy a new one. Protect the wheels from weld spatter if you do try this.

Colin. You are flogging a dead horse old chap. This topic expired seven years ago. Better to start your own topic. Locking this topic.

Steven. It would be worth looking at the relevent sections of the forum for the models you are interested in to get an idea of the pros and cons.

I have never heard a gearbox make the sort of sound you describe, but if it is the box it is probably too late to do anything about it. Nevertheless for peace of mind it won't hurt to get the oil changed.

Stephen. All your voltage readings tell you is that the alternator is working and that there is not a short circuit in the battery. They tell you nothing about the condition of the battery in regard to sulphation of the electrodes or the formation of dendrites which cause loss of capacity and an inability to hold a charge. To do that requires equipment that most owners do not possess so I suggest you get it professionally tested. As to coding, I have read (though I can not recall the source of the information,) that all VAG cars from 2008 require it, and some earlier models too. (My 2007 A3 did.) Uncoded new batteries will still work for a while though their lifespans will be shortened because of wrong charging rates. Incidently loss of radio presets and false dash warnings are symptoms of a battery that is dying. See this post: https://www.audiownersclub.com/forums/topic/28121-ignition-light-disco/#comment-113216

The EGR cooler is a common location for invisible coolant losses. It's quite an expensive job I believe.

Larry. All I'll say at the moment is that wheels are in motion.

It happens all too often unfortunately. Both common courtesy and the forum rules require some sort of aknowledgement from the questionner to responses he has received. In this case Ma has not even looked at the forum since posting his question.

I'm impressed.

It's hard to be sure without actually hearing the sound, but your description suggests one or more of the brakes is either not releasing properly or there is debrid trapped between disc and pad. Does the noise change when the brakes are firmly applied?

In that case I suspect the engine is misfiring. All the more reason to return it to the dealer without delay.

I can't really add any thing without more information. Perhaps I did not state my questions clearly enough, so let me start again. [1] What is the engine speed, not the road speed, when the vibration occurs in 5th gear? [2] What is the engine speed, not the road speed, when the vibration occurs in 4th gear?

You may well be right for all I know. My point was more that if the master cylinder seals are perished then the slave cylinder seals will also be in poor condition and liable to let go in the near future, so it makes sense to my mind to do both at the same time. I have always believed that if you do a job properly, you only do it once; whereas if you do a job poorly it will have to be done again. Anyway that's a decision for Mohame to make. We have presented him with two options to choose from, both equally valid for different reasons.

I think we can eliminate front tyre balance. That still leaves rear tyre balance, loose wheel nuts and a host of other possibilities. What is the engine speed when the vibration occurs in 5th gear? What happens when you drive the car in 4th gear at that same engine speed? On reflection I re-read the question and realised you have just bought the car from a dealer, so my response changes to take the thing back and let him resolve the problem free of charge.

I suggest you renew both the master cylinder and the slave cylinder. It may be that only one is defective at the moment, but at 13 years old the other will soon follow it into retirement.

Mornington Crescent.

Like Magnet I would go with the suppliers recommendations rather than be guided by what you have in the car at the moment, which will undoubtedly have been renewed a few times in an 18 year old car.