cliffcoggin

Well if you are certain all the air is out then the slave cylinder is the next most probable culprit.

Mark. You can buy special bleed tools to make the job a one man operation, but I have no experience of them. Alternatively if you can get the help of an assistant it will cost you nothing. One man stays in the car to operate the clutch pedal; the other man goes under the car to open and close the bleed valve. It helps to have a plastic tube on the bleed nipple with its lower end in a glass jar. The sequence of operations is: [1]The bleed valve is opened. [2]The pedal is pushed hard to the floor and held there. [3]The bleed valve is closed. [4]The pedal is raised, and the reservoir topped up. Repeat the above until no air bubbles are seen in the glass jar. It relies on good communication between both men with the pedal man being in command. Having said all that, it is possible you have a faulty slave cylinder or a worn thrust bearing, but that can not now be diagnosed until you have bled all air out of the hydraulic system. You might have saved yourself some time and expense if you had asked the forum before changing the master cylinder. Google is a very fallible source of information, and needs to be treated with caution.

Mark. Forgive me if I say you do not sound familiar with car repair, so please tell us how you bled air out of the system. Air is the most probable cause of your problem but it requires a particular technique to ensure its removal. It is not enough to simply open the bleed valve of the slave cylinder and pour fluid into the reservoir, which is what I assume you meant by "put 1 litre through the gearbox".

James. Your engine was notorious for a few years for consuming an enormous amount of oil. The solution was a total engine rebuild with redesigned parts, which Audi only reluctantly and after much pressure from owners was its responsibility. However, having done nothing about the oil warnings in the four months since you bought the car you have effectively accepted the car as adequate, so I fear your chances of any recourse from either Audi or the seller are pretty much zero. I suggest your best option is to swallow the bitter pill by scrapping the car and buying something else. Incidentally I reckon it is only worth about £1200, not the £3000-4000 you believe, if you can find a gullible private buyer for it, though that would be pretty mean. A knowledgable dealer will not touch it because of the known engine fault.

Thank you for letting us know Joshua. It is rare for folk to inform us of the ends of their stories. It's a shame it has taken so long, but you got the right result in the end. I wonder if the dealer will do the decent thing and scrap the car, or will he sell it again to another unsuspecting victim. Perhaps we be hearing of this car again. PS. There is an awfully long blank space at the end of your post. Is there supposed to be something there that my computer is suppressing?

Ah, that makes sense. I wondered briefly if you meant bullet connectors, but that they became obsolete years ago.

Bullets? I guess this is a typo but I can not decypher it.

The same question gets the same answer. Get it tested.

Elimination of the vibration and high temperature at that disc is good enough justification for changing it, though I am curious to discover if the black mark really is a crack. Could you drag a hard steel tool like a chisel or scriber across the line to feel if it catches?

Fair enough. In that case I suggest you get some diagnostic tests done as soon as possible.

What I am wondering, and at the moment it is only speculation, is whether the excess crankcase pressure you reported last year is responsible for the present problem. If the engine is blowing a lot of lubricating oil into the intake manifold it might explain the slow cranking on the starter motor, the blocking of the DPF, the clouds of smoke, and the runaway engine. Under the right (or perhaps I should say wrong) conditions diesel engines can run on their own lube oil. What is the mileage of the car? What is the oil consumption? What is the general condition of the engine?

Is this the same smokey engine you asked about 20 months ago? If so, what was the solution at that time? The obvious candidate for the smoke now is the DPF blockage. Whether that is also the cause of the uncontrolled revving seems unlikely. Possibly both problems are symptoms of a more fundamental fault with the engine. Runaway diesel revving is a serious problem and invariably ends badly, so it needs to be diagnosed and rectified before returning the car to use. I would even go so far as to say the car is dangerous.

As the problem began immediately after a service I would take the car straight back to the garage that did the work. I am not saying the garage is definitely negligent in its work, but it surely has a responsibility to ensure the car is returned to you in no worse a condition than when you took it in.

Have you read this topic? https://www.audiownersclub.com/forums/topic/18824-audi-a3-8p-everything-is-flickering/

Chuckle. You didn't expect him to return any more than I did Gareth.

It could well be the oil pump or some of the main or big end bearings. It could also be a timing chain or a hydraulic valve depending on the engine, which you have told us nothing about. No sensible answer can be given until you give us some details. How many miles has the car done? How old is it? Does it have a full service history? And just to be clear, are you are saying the problem only appeared after the service?

It makes sense to have every pad by the same maker so that the co-efficient of friction, and hence the braking effort, is the same on all wheels. (Pad compositions vary slightly from one brand to another.) I doubt that holds true for the discs as the steel is made to the same specification no matter who actually fabricates them. I have never heard of Klaxcar, but then I long ago gave up worrying about brand names after reading that the name on the box often had nothing to do with whoever made what was inside.

I have long been critical of the total reliance on computer diagnostics, untempered by any human thinking or experience.

It's disturbing that a professional could not discover such a simple fault for so long, but having happened once it is possible it has happened again. I suggest you take that cable off and clean the terminals with sandpaper or a wire brush. Ensure the screws or clamps are tight when you refit it.

Maria. It may be a defective instrument panel. See this topic for more information: https://www.audiownersclub.com/forums/topic/21817-electrical-fault/

Glad to hear the end is in sight.

Well that confirms there is a real problem. Do let us know the outcome.

I had forgotten about the filter which may be blocked. It is normally changed on a regular basis, perhaps every two years if I recall correctly.

I believe you are right about the flap being stuck, but I know of no way to test it without dismantling. On second thoughts, how about wafting a little perfume by the external air intake. If you then can not smell it inside the flap must be closed.

Have you tried the tip immediately above your post? Have you even read it?