cliffcoggin

In that case it is almost certain the thermostat needs to be renewed. It isn't a difficult job, but getting rid of the inevitable airlock afterwards can be. (If the cabin heater does not work after changing the thermostat you have an air lock.) Let us know if the engine reaches normal temperature afterwards and we can then move on to the fan problem.

Zak. This may seem an odd question, but it is not trivial, and may be relevant to the problems. How old is the battery?

The thermostat does not control the fans, that is the job of the temperature sensor. (Strictly speaking, any switch that is controlled by temperature is a thermostat, but let's not be distracted by that as it is contrary to convention in cars.) That the indicated temperature goes no higher than 70 without the fans suggests to me that either the thermostat remains open all the time or that the temperature reading is wrong. Does the temperature reading drop to the bottom of the scale when the engine is cold? Do you have a way to independently measure the temperature using a hand held infra red meter for example? At this stage I can not say whether the ECON fault is related to the temperature fault. I suggest you ignore it for the moment, but bear it in mind if you get other indications of a general electrical problem.

I could not agree more. Why throw more good money after bad? It's unfortunate that if one wants to buy a cheap secondhand car one needs to have enough knowledge to know what you are letting yourself in for in terms of fault rectification. This applies much more to any vehicle that has been mapped or modified in regard to DPF or EGR removal because it is so much harder to obtain good free advice.

Add an air lock to the list of possibilities. Has the cooling system been opened recently, to fit a thermostat for example or change a hose?

John. You have not mentioned how much you paid for the car, but I doubt it was a lot considering its age and mileage, in which case I fear it will cost you more in money and time to get recompense than the car is worth. I suggest you swallow the bitter pill and accept that you have been conned, then move on to either repairing or replacing the car.

They are Bowden cables: thick slightly flexible rods.

I'd agree it is a fault in the linkage rather than the gearbox. The cable adjustment may have loosened at the gearbox end, or the cable mounting bracket may be loose. You will need to examine the whole linkage to find where the slack is. I have not done the job myself but the Haynes manual suggests a complicated juggling of springs and locking collars to detach the cables.

If transporting the dogs is so important to you the logical thing to do is get rid of the TT and keep the A3.

Emma. I would largely agree with Jason that repair costs are going to increase as the car ages and wear accrues. So from a maintenance perspective it would make sense to get rid of it, but that takes no account of sentiment. On the other hand what are you going to replace it with? An expensive newer car will likely have fewer faults and lower maintenance costs, but a cheap old banger will be worse than your existing car. As the old adage goes "sometimes better the devil you know". It comes down to what you can afford to invest against the cost of keeping the A4.

The same issue gets the same suggestions. Have you tried them?

And thanks again to Joe for his analysis which I have marked as a solution.

Take it back to the dealer under guarantee.

England to Italy is not half as much of a stretch as the USA to Italy. And one does not need a sea voyage to do so.

Which makes the whole topic incomprehensible so I shall not be responding further.

Alan. Are you sure it isn't a leak from the rear wash pipe, which is a common problem? The pipe can split or the seal in the wiper motor can fail, both of which can lead to water in the boot. If you are sure the lid seal has been permanently over crushed then nothing can be done to restore the rubber's elasticity. From what I remember the rubber does not need to make an absolutely water tight seal as long as it is close enough to guide water into the drainage channels formed by the shape of the steel lid and body. However I don't have my A3 any more to check this point so I can not be certain. One other thing occurs to me. Is the boot lid closing enough to make a seal? Has the lid been twisted recently or the latch moved?

This topic may be of interest: https://www.audiownersclub.com/forums/topic/22696-tpms-option-not-available-to-reset-tyre-pressures/#comment-84915

David. I am going to leave this matter in Jason's hands as he knows far more than me, but I will add two comments. I don't believe the statement that the reversing lights are on the same fuse as the aircon and something else. The whole idea of having multiple fuses is to ensure each circuit is independant of the others, so that failure of one does not affect other circuits. What is your source for this information? I am not a fan of computer diagnoses without careful interpretation, however yours shows two instances of short circuits at the bolbs which suggests to me that the wiring is damaged or there is still water present somewhere in the light unit.

Sorry, I don't know. Perhaps examination of the light unit on the other side will give a clue.

David. It might be damaged wiring, but it's more likely to be corroded contacts in the bolb holder or a bad earth. Am I right in assuming you fitted a new bolb? You did not specifically mention it so I have to ask.

My 2007 model had a permanently live socket. I don't know about later models. A permanently live socket was fine when used for its original purpose of lighting a cigarette: current only flowed for 20 seconds, so there was no significant drain on the battery. Nowadays it is often labelled as an auxillary power socket, and is used for all sorts of electronic gadgets which might draw power continuously. The consumption of a phone charger is small and will stop when the phone is fully charged, but there has been a case on this forum of a dashcam draining the car battery because it continued operating after the ignition was switched off.

I can't help with the switch location, but I suggest that if the reversing beep works then the switch must be working. I can't imagine there are separate switches for the light and the sounder.

Michelle. In addition to Gareth's questions: does your car have rear wash/wipe? I ask because it has been known for A3 rear washer pipes to leak into the boot.

Aram. Two possibilities to consider: A3 instrument panels are prone to failure, usually with flickering lights or the instruments simply die. I have not heard of such a fault causing the engine to die. The panels can be repaired by specialists at a much lower cost than a new Audi panel. A defective battery can cause seemingly unrelated electronic problems with, for examples, cruise control, radio, air conditioning etc. Again I have not heard of such a fault causing the engine to die. Even if your battery starts the car easily it does not mean it is in good condition. If it is more than perhaps five years old it would be worth buying a new one. Don't forget to get it coded to the car.

Test the valves by rolling the stems on a dead flat surface with the heads overhanging the edge. Any bend will show up as a reluctance to roll smoothly and the head will gyrate or orbit rather than rotate.