darobot Posted November 4, 2011 Report Share Posted November 4, 2011 Howdy Folks, Been quite the lurker on here for quite a while now, so about time I made a post or two! Anyhow, i'm going to get a used A8 V8 diesel in the new year. I'm trying to weigh up the pros and cons of the 4.0 over the 4.2. It seems that you can pick up an 04' 4.0 tdi with sub 80k for about 8ki'sh now, which is excellent value. I'm a bit concerned on two fronts, however: Electrical faults and the general refinement of the engine (many reports say it's really noisy and you can feel vibrations under the seat at idle) The 4.2tdi is much pricier, at about 15k (almost double) but the engine along with being more powerful, is seemingly much more refined, and the electrical issues on the facelift model appear much less prevalent. Obviously the 4.2tdi isn't double the car, and therefore it's not really worth double the price. Both cars will potentially be getting remapped, so they'll be plenty quick anyway (even though a 370bhp 4.2 sounds amazing). I can probably live with the less refined 4.0 tdi with an extra 7k in my pocket, but the real worry is the electrical issues might start eating into that saving. Any thoughts folks? I'd ideally love to to test drive both, but in Ireland neither of these models are common. Link to comment Share on other sites More sharing options...
Mook Posted November 4, 2011 Report Share Posted November 4, 2011 Welcome to Tyresmoke darobot More money for the 4.2, but the resale value will be higher, as long as you can live with tying up the extra capital in the car. I'd take the 4.2 any day - it's a much, much nicer drive and they go like stink. Link to comment Share on other sites More sharing options...
darobot Posted November 4, 2011 Author Report Share Posted November 4, 2011 cheers mook Thing is concerning resale, in Ireland at least, pre 2008 cars are taxed on cc size and everything over 3000 cc is at a whopping 1566euro a year to tax the car. Therefore, as you might imagine, there's not much of a market secondhand for either car due to the tax rate (every drone here is 520d and 156euro a year tax rate obsessed) I'll be keeping the car for 4years or so also, so it'll be worth very little when I come to sell it anyhow. Obviously it's really the 4.2 that I want, but it just comes down to justifying the extra cost! Link to comment Share on other sites More sharing options...
RichardW Posted November 4, 2011 Report Share Posted November 4, 2011 I have a late 2003 4.0TDi which I bought when it was 21/2 years old from a main dealer. Admittedly I only do about 6000 miles a year (it has now covered about 57k) but everything still works and it has most of the nice toys including keyless go, fingerprint reader, comfort seats with heating/ventilation/massage, xenons with cornering lights, and the parking sensors (front/rear) have been upgraded to show on the MMI display as on later cars. I have had 2 problems; car went into limp mode 2 years ago (vagcom identified "implausible reading" from the pressure sensor on the intercooler) I reset with vagcom and it has not re-occured. Secondly, I had a soft "thump" from the gearbox when the box changed from 3rd to 2nd when coming to rest. This is a known problem but does not affect all cars. Cured by a change to the "blue" gearbox fluid and reprogram of the gearbox ECU by the Audi dealers in Northampton - once again this has not re-occured. I cannot justify upgrading to the 4.2 TDi, mine still goes extremely well (usable performance is similar to my previous D2 S8 4.2 petrol but 50% more mpg) and it is still a delight to drive. Two pieces of advice; ideally get the comfort seats (superb) and leave it on 18 inch wheels (20 inch look great but spoil the ride and do not give any great handling advantage). In standard spec the 4.2 TDi has more bhp but the same torque as the 4.0Tdi so in normal driving the difference is not great. I understand that the 4.2 TDi can be a little more economical but I get about 27/28 mpg on short runs and 34/36 mpg cruising on the motorway. Great cars in my opinion. Link to comment Share on other sites More sharing options...
beemerboy9 Posted November 4, 2011 Report Share Posted November 4, 2011 (edited) I have a 4.0TDi 2003, registered in September 2004. The big difference between the two engines is the fuel-injection system, the 4.2 runs at higher pressure and is more advanced. I have had an oil leak fixed under extended warranty (20 hours at £100/hour) and the gearbox fluid change issue described by Richard. The only electrical problems that I can recall being frequent are 1) The engine cooling fan controller. This affects my car but I can't be bothered at the moment. 2) The MMI screen failing to raise from the dashboard. I have heard of electrical problems due to people spilling coffee over the MMI buttons , and some folks have problems when they try and reprogram entertainment features on the cars themselves. Having watched an expert (thanks Craigyb) program in a parking sensor unit, I would not touch that sort of thing myself. I would be far more worried about the mechanical condition. The quattro drive train is complex and has more oil seals ready to leak than you could possibly imagine. Get any car inspected by an expert before you buy. My kids have left home, so I will be looking to downsize next time. Meanwhile I love my A8, especially the throaty roar from the engine - it sounds far more like a sports saloon than the 4.2. Edited November 4, 2011 by beemerboy9 Link to comment Share on other sites More sharing options...
darobot Posted November 4, 2011 Author Report Share Posted November 4, 2011 Thanks for the helpful replies guys. I would definitely be planning to get the fluid changed in the gearbox once purchased. Will most certainly be getting it inspected thoroughly before any purchase, as I have to travel over from Dublin to purchase, so it's a long way to view a lemon. Very excited about getting one, but it's the case of waiting and finding the right one now. Have either of you guys remapped your 4.0's? My only concern is that the increased torque might be very harsh on the box. Link to comment Share on other sites More sharing options...
beemerboy9 Posted November 5, 2011 Report Share Posted November 5, 2011 (edited) Have either of you guys remapped your 4.0's? My only concern is that the increased torque might be very harsh on the box. These cars are plenty fast enough in a straight line as is. The thing that limits how fast you can travel over an A- or B- road, is a) the width of the car b) trying to brake and then hustle 1950kg of car (excluding driver) round a sharp bend. Seriously, if you want to have "fun" then buy an Impreza Turbo or WHY. In five years of ownership of the diesel, I can remember 2 occasions when more power would have been useful on an overtake on an A- or B- road. That is when I considered a remap. In the past 10 years of driving A8's, I have been overtaken and left for dead once on a single-carriageway road by another car. It was in Scotland last summer and the overtaking vehicle was a very enterprisingly driven Ford Transit! I had to admit to the wife that I dared not follow where he was going. Hope this helps, John Edited November 5, 2011 by beemerboy9 Link to comment Share on other sites More sharing options...
darobot Posted November 6, 2011 Author Report Share Posted November 6, 2011 I'm just considering the map for that extra shove really. I drove a remapped Phaeton V10 tdi a while back, and by christ did that thing move... The roads where I live are far too narrow to be throwing around a car of that size anyhow. I'm decided on a 4.0 now and maybe get something fun with the savings, just have to hold out for a nicely minded one now. Link to comment Share on other sites More sharing options...
Recommended Posts
Please sign in to comment
You will be able to leave a comment after signing in
Sign In Now