cliffcoggin

To be fair, split gaiters are not in themselves causes for an MOT failure because they do not affect the handling of the car. It is only when the the joints lose their grease and dirt then enters causing wear that a failure is justified. That is the reason most MOT test sites warn of an impending fault by means of an "advisory" notice. The onus is on the owner to heed that warning to avoid an expensive repair bill, new boots being cheaper than new joints.

Gary. Not to gainsay any of Gareth's sage advice, but something to bear in mind with a private purchase is that you have little recourse if some major component proves to be defective; whereas a reputable dealer will either stand by any guarantee or be subject to legal redress. Only you can decide if you are willing to pay higher dealer prices for the sake of that extra confidence in the car. If you are not familiar with assessing second hand cars yourself you would find a competent assessor like the RAC would be very worthwhile.

Peter. Any work done on your car by an Audi garage during its existence will have its history centrally recorded, so it should be possible to find when and by whom the sensor was fitted. If you have had work done to it by a non Audi garage there will be no such record.

Please do let us know the outcome. The information would be invaluable for future reference.

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?