cliffcoggin

Thinking further on the matter, perhaps speculating further would be a better description, if the problem is outside temperature dependant I would investigate how and where that temperature sensor affects the ECU. I reckon there must be an temperature input to the ECU so that it can compensate for ambient air temp variation, but the details of how that circuit operates are beyond me. I suggest an auto electrical specialist would be the best option at the moment, because I have been distinctly unimpressed by reports I have read on this forum regarding the diagnostic abilities of even Audi main dealers. As I said before, if the computer says no, Audi are stumped.

Adrian. My first thought was the instrument cluster but as you have had that changed I am at a loss to think what else it could be. Did Audi have any suggestions, or did the problem not happen while the car was in their hands? Sadly the reliance on diagnostic computers has eliminated the human brain as a means of tracing car faults.

If the rubber boots were split ten months ago the joints they cover will undoubtedly be ruined by now and have to be renewed. It would have been much cheaper to get them fixed when the problem was first found. To get an idea of that cost, pick up a phone and call a garage.

Tell us the bite point of the clutch. In other words at what pedal height does the clutch start to engage? If it is much less than half way up you have a clutch problem.

You have not mentioned what sort of gearbox it has, but assuming it's a manual transmission the problem is most likely a worn clutch. When was it last changed?

The high pressure section of your brake system is losing pressure when the engine is off. That process is normal and inevitable because no seal is perfect, but I would expect it to take many hours or even days. It is not something I have ever checked. Unless you have a hydraulic brake fluid leak that needs the reservoir to be topped up, or a low pressure warning light, or it takes more than approximately 5 seconds to restore pressure once the engine is running, I don't believe you have anything to worry about.

If the light appeared immediately after the service I suggest you take it back to the garage. They may have simply forgotten to reset the service warning.

How on earth did a stone that size get onto the undertray? Had she been off-roading?

I suggest you complain to the vendor. It may not do any good but you have little other recourse.

Sorry, I can't hear anything like you describe, which leaves me guessing. Turbo air leak? Tyre noise? Slipping belt? Unless somebody comes up with a better idea I suggest you get it professionally checked.

I hear nothing but uniform road noise throughout the whole clip. You'll need to provide a better recording and a better description if we are to help, otherwise random guesses is all we can provide.

The bite point should be approximately half way up the pedal travel. Assuming there is no slack in that pedal motion it's time to get the clutch repaired before you damage the gearbox.

The most likely cause is a worn clutch. Where is the bite point when using it i.e. how far up is the pedal when the clutch engages?

You're welcome, and thanks for responding. Few are courteous enough to do so nowadays. Diesels are heavier and stronger than similarly sized petrol engines. All that extra metal takes longer to cool down.

Ryan. If you are saying the engine takes longer to cool after it has been turned off, and warm up time is shorter, then I don't believe there is anything wrong and they are just the result of warmer summer weather. Everything else in your report is perfectly normal.

Ir would be worth checking the continuity of all wires running up the rubber tube between tailgate and body. They have reputation for breaking.

Harry. A 12 year old car with sporty modifications and 117000 miles on the clock would be ringing alarm bells for me. The chances are it has been thrashed by a boy racer so don't get your hopes up too high.

Bård. It seems unlikely that there are various mechanical and electrical faults on three wheels at once so my guess would be a single fault in the brake module, however I can not be certain enough to recommend an expensive replacement. Another opinion here would be useful, or diagnosis on a professional Audi test rig.

Agreed. I would have expected Stuart's garage to suggest it as the next step.

That suggests that excessive pressure is being generated. My guess for the cause would be a leak at the cylinder head gasket or a restriction in coolant flow leading to boiling.

Stuart. You wrote that you can hear the leak dripping, but have you actually looked? Where specifically is it leaking from at the expansion tank? The cap, the hose connection, a hole in the side, somewhere else?

Glad you found the fault. The screwdriver stethoscope is always my first choice for diagnosing odd noises, though a proper mechanics stethoscope is easier on the ears and skull.

In that case I don't know as I am in England. Are you sure it is a matter of a poor signal rather than a radio or aerial fault? A bad aerial connection often causes crackling.

Which Melbourne?

Getting redress from a private seller is theoretically possible; in practice it is rarely worth the time and trouble. That's unfortunate, but it's one of the reasons private sales are cheaper than trade sales.