2.5 v6 tdi. Reliability?


Registered User
Hi there, was wondering if any existing or previous owners can shed some light on this model, after searching and not finding many topics on them, not sure if this is a good or bad thing lol.
I'm after another b5 a4 as some old lady killed my 19tdi se. Thort I'd try a 2.5 this time but theres not a great lot of them come up for sale, even less quattro's around! These will be nice in the winter!!
How many miles can you expect from a tank? My 1.9 110 used to get around 550 mile.



"Stick a V8 in it!"
Staff member
VCDS Map User
They certainly arent as good on fuel. Perhaps 35mpg around town and 45-50 driving economically on the motorway for a quattro.

These engines certainly have issues when compared with the 1.9. The two main ones are injector pump failure, and camshaft wear.

Cam wear is mainly down to poor servicing, incorrect oil and suchlike. The IP failure however is just something that happens whenever it feels like it, and it'll cost you ~1k to fix if it does fail.


Registered User
Thanks for the reply aragorn, 1k for the ip failure sounds a right ******, are there any tell tail signs for either of them problems? Something to keep in mind when viewing that's all!
I would have a 1.9 quattro too but they seem to be hard to come by.



Registered User
As Aragorn pointed, there are a few issues with them cams and IP failures beeing just a few. Early models had a cotton gauze engine breather/filter which will overpressurize the engine and blow the turbo seals- changing to later AKE design solves that for good. From a reliability point of view they are good engines and very, very strong. The fuel economy isn't great compared to a 4 pot VE diesel but it's twice as good as a equivalent v6 petrol engine (i know folks who struggle to average 20-30 Mpg in b6 audi a4 3.0 petrol engines either quattro or FW !). Quattro drivetrain will impact the average Mpg with a min. of 10Mpg compared with the similar FWD model. The old 1.9 Tdi quattro's are brilliant but a touch under powered- easily sorted with a few bolt on mods. I had v6 tdi for a few years and never had major issues, apart from regular maintenance and the odd aux. belt tensioner wearing out,brakes and susp. arms i have not replaced much on them and they are high mileage motors ! I had a few 1.9 tdi quattro's and i liked so much i decided to make my own mainly due to the money i spent on and poor re-sale values ! The only thing i cannot put up with is the poxy 5 speed gearbox as you need to rev the engine hard to keep it in the power band whilst up-shifting. A 6 speed gearbox has much nicer spaced gears and allows the use of stronger 240mm clutches. I have bought Jcb's Southbend clutch kit and single mass flywheel set-up so i can make use of the full potential of the soupped-up AHH engine with a estimated 180-200 Bhp... with room for more ! As a runabout it will do just nicely...

I would say do not despair and keep looking for a decent one but i would look for a a6 tdi quattro as well (better overall spec and good value for money). I have a w reg 2.5 tdi quattro 180Bhp avant sport which i would put up for sale in the next few weeks , really tidy motor and fully loaded: dual zone climate control, cruise, sports suspension, good engine, modded exhaust, new clutch and flywheel, tidy bodywork- high mileage but needs nothing. I only sell it due to purchasing a allroad to cope with towing duties. It's available for sale now but i'll rather hold till begining/mid November when eastern europeans start buying quattro's as they need to go abroad for X-mas holydays !


VW + Audi mad
I would certainly stay well clear of any early V6 TDI.
My stepfather has had a succession of A6's over the years, all second-hand with varying mileages and the only one that ever gave him hassle was a W reg 2.5 TDI Avant.
It was a FASH car but it was 12 months of hassle before he sold it in disgust, it had new cams, new sump gasket and main crank oil seals all done in the time he owned it, and still leaked oil like the Exxon Valdez.
I suppose the alarm bells should have begun when going through the service records it was found that a new radial fuel pump had been fitted by Audi sometime before at a cost of nearly £2.5k (seriously) , the fuel system at least didn't play up when he had the car.....
Ebay and the like seem to be full of cheap 2.5 TDI's, they look great on paper but I'd never again touch one, even with a barge-pole.
The 1.9 TDI's may offer less in theory but they seem to go wrong less often, and when they do it's not normally as expensive, plus they are more economical.
I've now done over 200K in 1.9 TDI's over the last 11 years and apart from normal wear and tear (belts and pulleys etc) have never had a moments trouble from them....
Last edited:


Registered User
I currenty have a 99 2.5tdi quattro and I loves it it returns 37.7 mpg on the combined, few nice mods here and there, and it has never shat itsself majorley and it's done 120k to date


Active Member
VCDS Map User
I got both of mine through cheap through the auctions, got the Avant for my wife, and was so impressed I got myself one too.
The Avant gets about 40-ish MPG town and Scottish country road driving, with the saloon getting 45-ish with less town driving. Reliability wise, the saloon has been great so far, the Avant not so, but rocks through the sump don't help any car. Almost all of my problems can be traced to living a mile up a dirt track!
The Avant has had a bit spent on it, a Vege engine and turbo(due to above mentioned rock), Diesel Bob was at the pump and injectors (to finish off the new engine) the DIS was done at ECU testing for lines and BBA's mistakes, and front suspension arms all done - I needed to do two or three, but went for them all due to my road issues.
All in all, I'd get another, which is about as good as you can say.


Registered User
If you buy the v6 tdi for economy purpose then 45Mpg isn't as bad is just when you're on boost on motorway where them engines came to their own ! As a all rounder, there's not better engine unless you go for the big boy- the 3.0 CR Tdi. You need to drive a good one to appreciate them, however they can be right pain to sort out if they go wrong... The quattro coupled with the torquey nature of the v6 engine makes for a very nice drive and if the car has the sports suspension then it's even more enjoyable on b roads and twisties !