I understand there has been a post on this subject in the past but there does not appear to be any conclusions. I am losing coolant, about half a lire in 150 miles. The system has been pressure testing but the pressure held and there is no signs of any leaks. The garage suggested that it could be an issue with the head gasket with water finding it's way into the exhaust. They suggested if this is the problem then it my be the time to sell the car (not a main dealer). Has anyone had this problem and found the fault.

Hello Peter,

Half a litre (one pint) in 150 miles is significant, and I would have to expected some evidence of where it was going. 
One simple test you could try:- 

Pick a dry day - if you can! 

Take the car on a run or at least 5 miles beyond the point where the coolant has reached operating temperature - longer if you can. 
Stop the car at a safe point, and without switching off, get an assistant to rev the car to a steady 2000 rpm and hold it there for 2 to 3 mins. while you observe the exhaust smoke - looking for white condensation type smoke. If there is any significant smoke then it could indicate HG issues, which would need further investigation before stripping. 
Perhaps you could let us know how you get on Peter.

Kind regards,

Gareth. 
p.s. I could be worth ‘investing’ in a new ( but only Audi) reservoir cap - can be the source of some coolant losses. 
 

Thanks Gareth, as you say, when, we get a dry day I will carry out the test. The area around the reservoir cap is dusty and perfectly dry, but yes I will purchase a new cap. The car has only done 40K miles and I really enjoy driving it, so I hope I can resolve the problem.

Thanks Peter,

Head gasket should be fine at 40K - as should the cap, but worth a try I guess. 
Just a thought ( and it’s late in the day for thinking at my age! ) - oil cooler?? Worth having a Google-? 
Kind regards,

Gareth. 

Hi Gareth.

I carried out the test you suggested, I drove 9 miles and then kept the revs up at 2000 for 3-4 minutes. The ambient temperature was about 10 degrees and the coolant temp was at 90 degrees and there was noticeable white condensation type smoke but with am ambient temp of 10 degrees would I not expect that? You mentioned additional tests, what did you have in mind?

Kind regards

Peter

I have just read an article on another website that suggests that there is an extended 8 year warranty on the water pump and thermostat on this car as it is a known area to leak. I can't be certain that mine in leaking from there but there is some damp in the area. Is anyone aware of a warranty.

Thanks Peter,

You (or the writer) could be right, and it maybe an exception to the normal warranty duration.

The thing is you will have to discuss this with your dealer and get that confirmed/refuted. I don’t see any other way forward other that getting an independent or local garage to strip and assess that at your expense.

Would you be kind enough to let us know how you get on Peter.

Kind regards,

Gareth.

Hi Gareth.

Reading it again it looks as if the extended warranty only applies to the US, I assume someone has taken Audi to court over the failure. You would have thought if it was good for the US it should be honored for all Audi A4. I will continue  to inquire and give you feedback later.

Regards Peter

I completed a 210 mile journey this week and lost half the coolant reservoir and there was a damp area near the water pump. At the end of my return journey 210 mile, no coolant was lost, very confused. However I think I am going to get the water pump replaced as this appears to be a poor area on these cars. Not however a cheap job. 

Thanks Peter,

Opinions may vary, and I can only say what I would do if it were mine - I would fit a dealer pump, rather than an aftermarket one, particularly if it’s not the easiest of jobs. 
Try Audi Parts Direct at Cardiff ( part of Mon. Motors - previously Cardiff Audi). You might find you can get a bit of discount. 
Perhaps you could let us know how you get on Peter.

Kind regards,

Gareth. 

Had a price from an independent for a new thermostat housing and water pump at £950 inc VAT, is that a reasonable price?

I also contacted Audi main dealer from where I purchased the car and asked about the extended warranty that is in the US and they said they would come back to me. In true Audi fashion they they have not.

My wife has a VW Golf 1.4 TSI 2016 and has been loosing coolant similar to your experience, which was the water pump. It was easy to identify the pooling on top of gearbox. Cost at VAG specialist using OEM part was £466

My A5 B9 looses a small amount of coolant (max to min in a few K miles) and has been pressure tested, but I can now see dried water/coolant at the outlet pipe underneath the reservoir.

If I were you I'd get a second opinion before spending £950

Had it fully checked out and it has been confirmed as the thermostat and water pump. I spoke to Audi UK head office and they said they are not aware of any issues with these parts or the extended warranty in the US and Canada, they look after the UK only!! I have had a few similar issues on this car and although it's a great car to drive I think it is going to be my last Audi.

I have a similar problem to PHB except on an Audi A6. While I was away last week a mechanic took a look at it and said it was a leak at the water pump, and he would advise that the water pump be replaced and as the car had 85000 miles on it, he would advise getting the timing belt done at the same time. Because I was only there for a day, he was not quoting for this job, but I will see about it this coming week and let you know what the price quoted was. In my car's case, I could see wetness at the bottom of the engine lying on the cover at the floor. 

I got a quote from an Audi dealer for £946 for water pump and timing belt. And that would be on top.of £140 to confirm the diagnosis. I've spoken to a couple of independent garages who just declined the job because it was too big.

7 hours ago, Allie said:

I got a quote from an Audi dealer for £946 for water pump and timing belt. And that would be on top.of £140 to confirm the diagnosis. I've spoken to a couple of independent garages who just declined the job because it was too big.

Hi thats a rubbish quote the parts from TPS O.E. are about £180 and the garages are probably still thinking you have to remove the whole front bumper and radiator as was on older models, you don't, if you just remove the plastic cover above the rad and remove the top rad bolts with the correct timing pins its tight but doable.

Steve.

Yes very pricey. I subsequently got the job done for £592 from an independent garage- water pump and timing belt. £220( VAT excluded) of that was labour.