cliffcoggin

Grant. I am still concerned that the warning comes on at high revs not low revs, however given your work on the oil pump, and the lack of noise from the engine, it's looking increasingly likely that the pressure switch is defective, but like you I would not want to assume that all is well. Add to that the suspicion that the switch was not in fact changed despite the old invoice I would certainly want a new one fitted before being confident in the engine. If you can not change it yourself your only options are to trailor it or drive it to a mechanic who can. I don't know your local road conditions but if the journey can be done slowly and avoiding any hills I would be tempted to drive it. That's a risk only you can decide on.

One of the clutches has worn out, which means the other is likely to be little better, therefore the whole gearbox needs an overhaul. That's going to hurt the wallet. Any chance of returning the car for a refund from the seller?

The question comes down to whether the low pressure warning is accurate or not. The only ways I can think to test it are to change the oil pressure switch for a new genuine Audi part that we can be confident is believable, or to find some way of attaching a pressure guage. The latter was something I used to do many years ago but I doubt there is a convenient attachment point to engines nowadays.

That's unfortunate, but having read the other recent thread on this problem you will know there is no realistic solution apart from a new engine.

So would we, but like so many who visit the forum for advice he could not be bothered to let us know the outcome. Too idle or too ill-mannered to make the effort I suppose.

Yes indeed. https://msautoservices.com/ is the place I took my A3 to. The owner, Michael Summers, is the person who alerted me to the problems a substandard battery can cause for the ECM and other delicate electronics, while allowing electro-mechanical equipment such as the starter and the wipers to function normally. In my particular case I would sporadically lose air conditioning and cruise control, and the engine would go into limp mode. A new battery fixed the problem.

A simple voltage reading will not tell you if the battery is fully functional. It needs to be tested on a high discharge test rig.

Please let us know the outcome.

I never knew such refurbishment was possible. At 180 Euros that has got be a bargain.

Ah, understood now. I expect the dimensions would be the same, but it's possible the cooling capacity (number of coils and fins) and the fan capacity (cubic feet per minute) may be lower because of the lower engine power of the 140 HP. I suggest waiting for a more definite answer before buying.

Fair enough Tom. What is this common fault that I am not aware of?

You're not the only one to not know what a rad pack is Gareth. I await Rizwan's reply.

Any particular reason for buying new? What about a secondhand one from a car breaker?

Elena. If the radio was removed before you bought it, or the battery was disconnected at some point, you may have to enter the four digit radio code to make it work. That code will be in the handbook that came with the car.

Definitely worth getting battery and charging system tested before doing anything else. Equally definite is that you should not be getting the head taken off. If that is all you garage can suggest, go to a better garage.

Fair enough. I can't suggest another specific fault that would link all those symptoms.

Those symptoms all suggest a defective battery. Was the replacement battery new or secondhand?

As far as I recall it is the word AUTO on the light switch.

Walk away from it Anna. There are plenty of decent diesels coming onto the market with the advent of electric cars and the ban on the sale of new diesels in a few years time. There's a very small chance of an innocuous explanation for the moisture, and a very large chance of a serious problem, so why take the risk?

David. If the DPF is genuinely blocking too soon, rather than there being a faulty sensor, there has to be a reason for it. See these videos by a very knowledgeable qualified engineer. You'll have forgive the heavy satire and "fruity" language in places. https://www.youtube.com/watch?v=tcML0N5s9_8

Grant. I have to question the diagnosis of a faulty oil pump. I would expect a worn pump to generate low pressure at low engine speed, and high pressure at high engine speeds, but your problem seems to be the opposite. Look at this article for some clues to the problem: https://www.700r4transmissionhq.com/low-oil-pressure-audi-a3/ I would also suspect the pressure relief valve to have a broken spring. Those valves were within the oil filter at one time. Whether that is still so I do not know.

A battery test would be worthwhile before spending any money on the car. How old is the battery?

It's a pity you did not mention December's battery problem when I asked yesterday about how well the car had been running, because defective batteries are known to cause just this sort of electrical problem. It's precisely why I asked the question. I suggest you possibly now have another faulty battery to replace as well as whatever work is necessary to cure the charging problem.

VAG are known for having parts that are common from model to model, and even brand to brand, so there must be something that will fit. Identifying the right part is the hard bit.

George. Did it run well prior to the week of inactivity? If so perhaps the weather is relevant and water has got into the tank. I suggest you open the fuel line in the engine bay and bleed some fuel into a glass jar watching for any water, dirt, rust, or air as a first step. Check the fuel filter again.