cliffcoggin

For clarification Martin, is the juddering when you are slipping the clutch, during take off for example, or when it is fully engaged? If the former I agree with Gareth; if the latter something else is wrong.

What engine? What fuel? What transmission? Give us a clue Martin.

Well I could see no picture in the video, there was only a faint sound; and telling me the smoke looks like vaping means nothing to me. In the absence of any evidence to the contrary, such as coolant loss, sooty plugs, blue colour in the smoke, or a road test, I would go with the garage assessment of steam condensing in cold air. (Water is a product of the combustion process.) Sorry Will, but you have not convinced there is anything wrong. Can you supply any other information?

Revving the engine whilst parked outside your house is not the same as accelerating hard. Take it to a suitable road where you can accelerate with your foot to the floor for at least five seconds, and report the smoke appearance. You have not mentioned any garage until now. Tell us more.

If you can see the smoke it must have a colour. Describe it.

Is the smoke white/grey or blue? Does it get worse during hard acceleration? Is there a thick coat of soot on the spark plugs?

And the injectors?

The chances are that petrol has spoilt the seals in the fuel pumps and injectors so they will likely need to be changed. I hope your friend has deep pockets.

If the rubber gaiter has split and allowed grease out, there is a good chance dirt has got into the CV joint and worn it. That could account for the knocking sound, particularly on extreme lock, though I doubt it would cause any play in the steering so that must be a different problem. Test it by gripping the driveshaft with big locking grips and try to turn it both ways. Any rotational play at all means the joint needs to be changed. You mentioned earlier that one of the links needs to be changed. Do you mean a steering link because that would undoubtedly cause slack steering?

Daryl. You won't see anything simply by looking. You need to force the noise to appear while looking and feeling and listening. (Your ears and fingers are as good as your eyes when detecting small amounts of play.) As I mentioned earlier, test the steering joints with the wheels on the ground and an assistant rocking the steering wheel enough to induce a little movement at the road wheels. Test the wheel bearings with the wheels off the ground and an assistant violently shaking the wheels left/right and top/bottom, then spin the wheels and listen for roughness. Test the suspension with the wheels off the ground and use a crowbar to lever under the links. If all the above proves satisfactory inspect the exhaust mountings, engine mountings, undertray if it has one, the valence, the bumper, the battery clamps, anything in fact that is bolted to the car. To repeat, you need to strongly shake each component rather than hope to simply see a gap somewhere. Until you prove the noise is not related to the steering or suspension I suggest you keep the car off the road. Any problem related to the safety of the car is an offence under the Construction and Use regulations.

It could be many things. Have you looked under the car while somebody rocks the steering wheel? Watch for play at ball joints, rack mountings, etc.

From Audi perhaps?

I can't help. I am only writing to add that I have the same fault occasionally on the O/S/R door and boot lid, though it does not yet irritate me enough to do anything about it.

Perhaps, but that is not how it read to me. Nevertheless I agree with you that the problem should be investigated rather than simply dismissed as a faulty sensor.

Adam. On the facts you have presented nobody can possibly tell you what is wrong. It may be a turbo fault, it may be a damaged duct, it may be something else entirely. You or your mechanic need to first of all look for visible damage, and then proceed from there depending on what you find. Error codes can not be relied upon to tell you precisely what is at fault; they can only point you in the general direction.

Why do you disbelieve the sensor? Maybe you genuinely do have a restriction in the exhaust system. To simply buy new parts at random in the hope that the warning will go away is foolhardy and wasteful.

Paul. Don't just put down the shovel, chop it up and bury the bits so that it can never be used again. Unfortunately I reckon it is time to cut your losses and sell whatever you can, for whatever price you can get, then start afresh with a properly inspected car. You are going to lose a fair bit of money, but the alternative could well cost a great deal more. If you had bought a new engine I might offer different advice, but you bought a secondhand engine of unknown condition that you want fit into an extremely secondhand car, either of which may throw up more surprises once it is running.

What makes you doubt Audi's recommendation? I have not read any untoward comments about it except for the price.

Robert. In your position I would approach the problem by looking at, or testing, the various categories or systems to eliminate them from the equation one by one: [1] Fuel. Is there any? Is it getting to the injectors? Are the injectors working? [2] Electrical. Is the battery in good condition? Is the ECU faulty? Are the fuses and relays intact and working? Is the mass flow sensor working? [3] Engine. Is the cambelt unbroken? Is the EGR blocked? Are the piston rings unbroken? Is there full compression in the engine? [4] Turbo. Is it undamaged? Are the ducts split? That is just a small sample of the possible faults you could have. There are many more. I have just realised that your car is newly purchased. If it was from a dealer I suggest you try to return it under guarantee as its repair may be relatively cheap (in Audi terms,) or it could be very expensive.

Robert. It could be a hundred or more faults from a faulty battery to a broken cambelt causing the problem. Without a lot more information it is unlikely anybody can help. Do you intend to investigate and repair it yourself, or will you take it to a mechanic?

To answer your question directly, yes you need a new battery. The fact that it appears to recharge in 10 minutes is not a reliable indicator of condition because batteries can fail in several ways: internal short circuit, disintegration of the electrodes, loss of electrolyte etc. The only reliable test is the high discharge test (also known as a deep discharge test,) which few owners possess. A hand held voltage tester is no use at all.

There is no fixed End Of Life date for any engine. Engine life depends entirely on how carefully it has been driven and how well it has been maintained. You know the latter, but do you know the former? Having said that, it can not have been maintained too rigorously if it needs all that work on the braking system.

Possibly the window limit switches needed to be reset, which you did with the key.

Rob. It seems I have misread your problem as being the handle not operating the latch, whereas I now realise it is the keyswitch not firing the solenoid. Sorry about that. Nevertheless I still think you need to get to the barrel to check the switch.

If it has been serviced correctly according to the schedule you need do nothing, however be aware that an expensive cam belt change may be imminent, and a gearbox oil change if it is automatic.