cliffcoggin

All engines fail eventually, particularly if poorly maintained. All diesels have DPF problems unless maintained. I've never heard of such oil pump problems. Who specifically has voted that engine the least reliable? In short I don't believe the Audi 2 litre diesel is any worse than other brands. Mine has done nearly 100000 miles and is still in fine condition.

The most likely culprit, amongst several, is the car battery is dying.

What stories have you been reading?

Why the duplicate topic Kyah?

Kyah. An improvement from a new pressure cap suggests poor engine cooling. Is the engine overheating? If it is then the water is probably boiling away as steam. A pressure test might confirm a leak but it could equally well be blockage in the radiator. Are the carpets dry in the front foot well? If so it is likely the heater is leaking. It would be an expensive repair but cheaper than the alternative of an internal engine leak. If you conclude that water is disappearing into the engine there are still several possibilities: [1] The head gasket. A compression test should reveal if this is so. [2] The water pump. This will be revealed by water in the engine oil forming a brown emulsion. [3] Possibly the EGR valve which I think is water cooled. I hope somebody else can confirm this point.

The knocking will always be less, or even non-existent, when the clutch is depressed because no power is being transmitted through the joint. You can test the joints by gripping a drive shaft in self locking grips and violently trying to twist it back and forth. Any movement or noise at the joint demonstrates it is worn. Do it with the wheel on the ground and the gearbox in neutral to test the outer joint; do it with the wheel in the air and a gear selected to test the inner joint.

Hello Adde. Those noises are typical of worn CV joints. You wrote that you have changed one joint, but are you aware that each drive shaft has two CV joints? I suggest you renew the other three.

Hello A (Anonymous?) If you have never worked on a car before the best tip I can give you is get some instruction from somebody who knows what he is doing. Learn how to use the tools, how to immobilise the car, how to jack it up safely, and even how to clean your hands at the end of the day. To imagine you can charge in knowing nothing more than a few fault codes is the height of foolishness.

Emma. There is no way one can value your car without a lot more information, plus an inspection, plus a test drive. Sorry but "beautiful and really well maintained" is not enough. The value will depend principally on condition, age, mileage, and service history. I suggest you get it inspected by the AA or RAC, who are probably going to be the closest thing you can find to independant assessors without vested interests. At 13 years old it is getting a bit long in the tooth, so be prepared to be disappointed by its value.

I have never noticed anything like that on mine, but then I don't turn off the engine with the bonnet open, so whether it is normal I know not. I suppose if there is pressure downstream of the turbo when the engine is switched off the only way for the air to escape is back through the turbo. Let's hope someone else can chip in.

How did you resolve the problem? Were you able to save the old battery?

Shah. 1) There is a good chance, but no certainty, that a new EGR valve will cure the problem. It depends how far the soot accumulation extends. 2) I don't know what you mean by adapting the pressure sensor.

If you bought the car from a dealer, take it back. Defective wipers are an MOT failure and therefore illegally sold to you and illegal to use on the road. If you are determined to fix the wipers yourself the first thing to check is the fuse.

Starter motors take 200-300 amps so you have been reducing battery capacity each time you started the engine. You should have left the car unused and just run a trickle charge once or twice per month.

The battery is clapped out. Running the engine for ten minutes a few times per week will not compensate for the heavy drain by the starter motor each time it is started. Try a mains powered charger over night, but don't be surprised if it can not restore battery capacity.

Undoubtedly.

I thought you had changed the top mounts already, Andy.

Look at the top spring mounts. If the spring does not seat correctly it can lead to creaking. You will need spring clamps to restrain the spring in order to move it.

As far as I recall those can also be the symptoms of an instrument cluster fault or an ECU fault. I don't know how you would pin down the actual problem except by replacement, which of course is a hugely expensive solution that could easily exceed the value of the car.

I don't recognise the noise, but it's odd that the clatter rate seems to be constant even when the road speed increases.

https://duckduckgo.com/?q=Standard+specs+for+audi+a3&ia=web

Yes I can hear it now and it sounds horrible, though I can not positively identify the noise. Possibilities to examine are: loose timing chain (if you have one), broken exhaust mounting, worn bearing in alternator or water pump or power steering pump, worn turbo (if you have one).

Sorry Thodoris, but even at maximum volume the sound is quiet and I hear nothing unusual.

No it is not normal for the lamp to illuminate at all. I echo Steve's recommendations.

Andy. In the past year or so there was a post here from somebody who repaired his door wiring. Search through the forum history to find it.