2.5 TDI engine, any good?

[csh1234]

Hi all,

Looking at buying an A6 TDI to go with our S8 :-) Need to do some miles for work, and can't bear the cost of the petrol! I am trying to decide between the 1.9 and 2.5 TDIs - I am tempted by the 2.5 as I think I would prefer the extra torque. Is the 2.5 generally a good engine, any specific problems to look for? I will probably try to find a 6 speed manual to give better mpg at motorway speeds...

Cheers

Chris

[Mook]

I ran a 2.5TDI Allroad - brilliant engine in a great car. Get a 180PS version (bigger turbo) and get it remapped. AmD did mine and it went to 230bhp and 340 ft lbs :D

Nothing specific to watch for - just make sure it's got a full history and get the engine oil flushed when it's serviced to stop crud getting up to the turbo.

[cruiser647]

I love the sound of the V6 diesel........

Get the 180 if you do.

However, the 1.9 is more economical (much noisier and more gruff).

The V6 TDi also went into the Passat, Skoda Superb and the A4 - so you have some more options there.

Personally, I'd get the 2.5 due to the lovely sound. Beware the fuel pump. Many have had woes with them. They cost £1200+ to be fixed/replaced.

Tipex on here hates the engine, Dave on here syas they are an 'all or nothing' engine in the performance it gives. Mook 'spiced' his up to 220 BHP??? I think, so haver a drive and see what you think.

It's a heavy lump, and can affect handling (but you have the S8 for fun!!)

[csh1234]

Thanks for the views. Any idea of what real world mpg I would be looking at, assuming 50 mile each way daily motorway runs...

[cruiser647]

Geezer here with a manual Avant quattro gets 35 - 38 on a motorway run.

You'd get more from the other lighter cars mentioned.

[Mook]

I used to get 31mph long term average, but the Allroad is a heavy car at 1.8 tonnes. You'll get 35mpg out of an A6 on the motorway

[Tipex]

I think 'hate' it is a bit strong, I just think it's a very old, underpowered overweight lump.

It does sound nicer than the 4 pots, as far as sounding nice goes for a diesel.

I just think the 4 pots are a better option, even the 130pd could be remapped to almost the same power as the 2.5, and being lighter, it's performance was actually a bit better, and it's way more economical.

I know some people like the extra cylinders and smoothness, but I've never found the Vag 4 pot diesels to be not smooth, and if your buying a diesel, surely your buying it for economy, so if you can get the same performance, using less fuel, why would you buy the 6 pot?

[beemerboy9]

The cost of depreciation on a second car plus the tax and insurance will be far more expensive than running the A8 compared to the A6 diesel

But if your heart wants to buy a second car don't let your head put you off.

[BW2309]

Any pre-2003 cars had cam shaft issues. Early ones had hollow shafts with iron shrunk-on lobes. These lobes split and come loose when worn. They tried to rectify this with solid, cast cam shafts but upto MY 2003 these were prone to wear (upto 1.5mm!!!!!) on the lobe tips. This causes a lumpy idle and lack of power.

Aside from that, just be SURE the timing belt changes have been done corectly and that the injector pump is OK - a new one is £1400!!!!!

Oooo, sorry, one last thing - the breather filter that sits in the Vee beneath the turbo can become blocked and this causes huge smoke that people often mistake for a knackered turbo! Use good quality diesel and the turbo will be fine - use crap and it can foul and the Variable Vanes sieze. Again, a new one is dear as this turbo is specific to the V6 TDi 2.5.