2.0TDi Common Rail engine losing water - Any common places?

After swapping A3's from a 2007 2.0TDi to the 2010 2.0TDi common rail I thought I'd be trouble free for a while.
On my '07 I had a problem where it was losing water which thankfully turned out to be the rad. I had this changed at Audi and all was sorted. I managed to see it was coming from the radiator as I put a pressure tester on it and after an hour I could see coolant collecting along the seem at the bottom.

Well, I picked up my new (to me) A3 a couple of weeks ago and now this one has started slowly losing water too

I borrowed the pressure tester again and got it up in the air and took off the undertray to look at the bottom of the rad again, but this time everything looks dry. In fact I can't see any dampness or signs of leaks anywhere in the engine bay, it just looks uniformly dusty.
I suppose it's possible it could be the rad, but just leaking from a part further up that I can't see from underneath.

I've tried a new expansion bottle cap on it and that didn't make any difference.
It was topped up to the seam on the bottle when I got it, and in 2 weeks of driving (400 miles or so) it's dropped about an inch in the bottle.
I always check it when it's cold, first thing in the morning and it's always parked on level ground in the same place, so I know it's a fair comparison.
It drives perfectly and I haven't noticed any white smoke/steam from the exhaust.


On the early BKD engines there was the issue with porous heads (coded A/B) and possibly the EGR cooler, but this new type engine is laid out very differently and I can't even find the EGR cooler to see if it has any external leaks visible.

Has anyone got any ideas if there are any known issues with leaks on the common rail engines?
Or anything else I can try. I'm reluctant to take it into Audi for investigation as they'll start replacing things to eliminate them and that'll cost a fortune that I don't have after paying for the car.

Also, the warranty expired about a month ago, do Audi offer any sort of assistance when things go wrong just outside of warranty, or is it a strict deadline and I'm on my own? It does have a full Audi service history.

Can anybody give me some good news concerning this as it's taking the shine off owning my new car

Thanks for the advice Nigel, that's sort of what what I was hoping to hear.
Do you think it would be worth putting a call into Audi UK first?
I didn't know if the dealer would need encouragement from Audi UK to look at this under warranty.

I thought I'd better do an update to this thread in case someone comes across it when doing a search.

Spoke to Audi UK and they said that the history showed that the previous owner had reported a drop in coolant in January. They changed the EGR cooler and told him to keep an eye on it, but he was due to change the car and didn't follow it up obviously.

Audi said it was out of warranty and there was absolutely no means of submitting a claim after the end date. They did say that they offer a good will policy for situations like this, but this was up to the dealer so they'd get Watford to call me.
Watford booked it in and agreed to cover all the investigation costs under good will and then said they'd discuss costs and contributions depending on what it was.
It turned out that after a very long pressure test the water pump was very slightly leaking.
They said they'd pay 30% of the labour and 70% of the parts as they classed this as a wearing part. They quoted £480 for the job.
I said as the timing belt was coming off then how much to do that at the same time. They came back saying £600.

I then had to query this as they normally charge £599 for a timing belt + water pump change. They said something about that being an offer price and that the good will is deducted from the full retail price. After a bit of haggling, they agreed to do it all for the cost of a standard timing belt change (£439) and they'd cover the water pump and the investigation labour under good will.

I was more than happy with that and at least I've had the belt changed now. They initially said it was due in 4000 miles (at 75,000), but then I asked if that was right as the handbook says different and he went away to check. He phoned me back later and said that he'd looked into it and for that engine the belt should be changed at 133,000 miles or 210,000km. As the belt was coming off and the cost of changing the belt and pump was less than just changing the belt in my case, I thought I'd be crazy not to get it done anyway.

It's now been 3 days since I got the car back and everything seems ok.
When it had been standing on the drive overnight I marked the water level (which was about an inch over the max mark on the bottle for some reason) so I could moniter it. The next morning I checked it and it seemed to be about 1mm lower, but I guess it could still have had a couple of air bubbles that were working out of the system. I checked again this morning and it doesn't seemed to have moved any more, so I guess it's settled down now (hopefully!).

One thing I did notice however, is that the fans came on when I got to work. I hadn't noticed this before. I checked the gauge and the oil temp in the DIS and they were both fine. Maybe I'm just paranoid now though.

All in all I was very pleased with how it went. Audi UK didn't do too much, but they did say that if I wasn't happy with Watfords decision then I could call them back and they'd get the regional manager to have a word with them.
M25 Watford were very good though and despite the pricing confusion, they were very flexible and helpful. I just hope this has solved it and the water level doesn't drop over the next week.