I think we have both arrived at the same conclusion from differing aspects of the same problem.

Large firing angles coupled with high peak cylinder pressures are certainly a major problem with a 3 cyl diesel, but if you were to drive one of the latest VAG offerings (Fabia Greenline for example), the installed engine appears smooth enough to the user except perhaps at the very lowest crank speeds. It's worth bearing in mind that peak cylinder pressure is not often achieved - an economy diesel will spend most of its time on light load or overrun.

Primary imbalance on overrun is unpleasant in a vehicle and very obvious - which is why even a bargain basement VAG diesel has a shaft to counter its effects. Whatever the final solution, its implementation has to be of lasting use to the user.

VAG has not distinguished itself in the field of diesel (and many other) engine design since the 1.9 PD was introduced. Some of the most elementary design mistakes have been made in the last decade or so, such as:

Chain driven balancer shafts - killed by torsionals

Piezo injector stacks running in oil - conductive oil shorts them out

Ceramic glowplugs sold in a high-sulphur fuel market (USA) - sulphur is aggressively acidic at combustion temperatures, making the ends fall off

One wonders whether their Chief Engineer has been asleep on his watch - in terms of applying the Laws of Physics to the products for which he is responsible and also quite possibly for his(?) recruiting skills.

The backup of these questionable designs from VAG has not been to anything like my own standards of trading integrity. Choose very carefully.

659.

Hello

Firstly, I'm new to the posting message process- forgive me if I get the process a little wrong.

I have a 1.4 Fabia (2010) Greenline with one of the 3 pot Engines (AMF) together with a counterbalance shaft driven by a chain. I bought the car from new - it managed to complete 95k miles without problems.

The car has been regularly serviced (by me) with oil and oil filters (and the sump oil drain nuts) all purchased from the dealership. Filters and oil purchased were those recommended to me on provision of the service document to the dealership staff.

The car has been back to the dealership once - for the replacement of the cam belt.

The car recently broke down on the motorway - all symptoms pointed towards an oil pressure problem (AA provided a road-side provisional diagnosis). The vehicle was recovered to the dealership; they set about providing a diagnosis of the reason for failure.

Dealership came back with a diagnosis of a wrecked Engine due to the counterbalance chain breaking and wrapping itself around the crankshaft. They informed me that pieces of metal were found at the top of the Engine in the valve gear. They have suggested a price of £5100 for a new Engine and fitting.

No 'goodwill' from Skoda and no 'goodwill' from the dealership.

Reading further on the forums suggest that this is not an isolated failure - many other people have suffered from thie failure and have had the same 'brush off' from Skoda and their dealerships.

The combined wisdom appears to suggest that the chain that drives the oil pump and contra-rotating counterbalance shaft is a 'life of Engine' component - which I take to mean there is no service regime (check/replacement) for this component.

Bearing in mind - the car was purchased (and a premium was paid for the Diesel Engine) on the basis or reliability, durability and longevity, it would seem that the car has (on any reasonable expectation) failed to live up to expectation.

My experience (with Peugeot and other Engines) suggest that 200K + miles is not an unreasonable expectation for a carefully and regularly serviced Diesel Engine.

Some 'wriggle room' has been suggested on the assumption that a stretched chain would provide some external indication (strange noises from the sump) of potention failure. I certainly did not experience any noise from the distressed chain and - since the vehicle has just recently been in for a cam belt change - neither did the dealership technicians; otherwise I'm sure they would have alerted me.

I'm told that this Engine has been used in Audi , Volkswagen , Seat and Skoda vehicles. Based upon my sorry story - I'd suggest that potential buyers avoid models that are powered by this Engine. Either that or in initate an inspection/replacement of the chain on the cam belt replacement service interval (this would be the most convenient time to inspect/replace the component).

Best regards.

Edited by JohnWinchester on 17/04/2014 at 11:29

John, I'm glad you came back to us and as moderator I should have said 'welcome to the forum'. I'm also glad that my impression that you were servicing the car properly was correct: it's just that the manufacturer has no way of knowing how competent DIY servicing has been, or how well the car has been driven.

With 95,000 miles under its belt in 4 years, your Fabia's engine has clearly done some long trips. I'd be interested in your view as an engineer as to how well-suited a little 3-cylinder engine is to that sort of use. Certainly one could have expected the VAG 1,9 TDI to have done that mileage without major failure.

Some readers will know that as a former tester of diesel engines, I have made something of a study of the earlier VAG PD engines - and I have commented on the 3 cyl 1.4 engine above.

Now that these engines are old, my predictions concerning the longevity of the chain drive to the balancer shaft and oil pump have proved to be correct - it's useless.

A balancer shaft deliberately introduces torsional oscillation into the rotating system of the engine - that's what it's there for. At some engine speeds resonances will occur, giving rise to very large forces. A chain has no means of absorbing the energy contained within these oscillating masses - it's infinitely flexible in compression and inelastic in tension.

This conspires to make the set up the disaster it has proved to be. The problems with the chain on the 1.4PD have nothing whatever to do with maintenance - they are caused by the designer displaying complete ignorance of the Laws of Physics.

As I have often said of VAG - there are some good products out there (1.9PD) but there are also far too many with fundamental design faults which could have been avoided by the application of basic Physics and above all, common sense. The back-up given by this organisation does not meet my standards of trading integrity - so my advice would be to go very carefully if you buy products from them.

659.

Edited by 659FBE on 18/04/2014 at 17:02

Regarding long-life servicing - of any marque - I'd have to utterly agree. It is probably the most profitable solution for the manufacturers in the long run (after all, you lose one disgruntled customer to another marque, and gain one from that other marque), but it really smacks of milking those customers for every penny you can.

Regarding getting extra oil changes done : I've got one of the 'new' F31 BMW 3 series estates (privately owned, not business). Usual official BMW oil change interval is 18,000 miles (roughly). All I do is book in at the halfway point for an oil and oil filter change. Surprisingly, BMW main agents aren't that expensive for that, about £160.

Considering that my fuel, tyres, a 'normal' annual service, insurance, car tax, etc. work out at somewhere around £3,000 a year, that extra £160 really is lost in the background noise. Then, if you add in depreciation, that £160 becomes pretty insignificant.

It's difficult to predict reliability until an engine has been in production for some time - but a few observations:

The high pressure fuel pump is almost as highly stressed as the PD unit injectors - but has to survive on fuel lubrication rather than the optimised lubricating oil in the PD. This makes the engine extremely intolerant of mis-fuelling or poor fuel system maintenance. I would not expect a CR high pressure pump to last the life of the engine. (Bosch PD injectors nearly always do).

The oil pump drive coupling is still suspect on these engines - a carry over from the balancer 2.0PD. They have improved the depth of engagement of the coupling hex (axially and radially) and may have improved the concentricity tolerancing. I still give it 0/10 for engineering design in view of the torsionals present.

The CR has the same silly water pump location on the tight side of the cambelt - change at every belt change.

Away from the engine, DPFs can be troublesome and will likely cost maintenance money before you throw the engine away. Its differential pressure transducer (locted cosily near the exhaust) is a frequent failure item - not a deal-breaker though.

659.

Would you mount a boost control electrical actuator with feedback control electronics 3" away from a red-hot turbocharger turbine fitted to a vibrating diesel engine and expect a long and trouble free life?

No , but then the people you hear from most who rave about modern diesels are buying new or nearly new and they are still within warranty, changing to another when it runs out, and leaving some other poor chancer to play russian roulette with the cast off's.

Apart from anything else, older diesels stink. I am behind at least one or two daily. Who bothers to check whether the EGR valve is working, or clean out the manifold as part of their maintenance? Not many I would think.

I forgot to ask when would you reccommend cleaning the EGR valve/manifold on the 1.9 PD and on the 2.0 CR? Is this very exspensive?

Edited by 5cylinderdiesel on 25/04/2014 at 23:19

659FBE why are you asking whether B Warner is now building teh turbo's? Are they better or worse than Garrett and why? When (what sort of mileage) would you be cleaning or replacing the EGR valve on your 1.9 PD? Or do you driv eit till it shows signs of blockage? Are there other things to consider when doing this?

Thanks again

QUOTE:...""Apart from anything else, older diesels stink. I am behind at least one or two daily.""

What's worse is a poorly tuned petrol engined banger - where you get a cocktail of exhaust fumes, burnt oil and worse, a whiff of unburnt petrol from leaky fuel system!

When catalytic converters started being fitted to petrol engine cars, it was quite common to get the smell of rotten eggs (hydrogen sulfide) from the exhaust. Not having had a petrol engine for the last 10 years I was wondering if this still happens?

I've not noticed it yet from my new petrol A3. Have they reduced the amount of sulfur in petrol and made the problem go away?

Great thread, I have an AVB 100hp A4, an 02 Avant with just 75k on the clock (bought it @ 45k) I have no intention of getting rid. The vehicle drives well with regular 5k oil changes,

I've never cleaned out the EGR, what are the symptoms of it being gummed up? I do occasionally get a slight hessiation at low revs, could that be the cause?

I always find your posts fascinating and informative 659, so thank you for taking the time. One thing I wonder is when your 1.9PD eventually wears out ( I have one too-the BXE 105 version), what will its replacement be? Will you stick with diesel for its efficiency but now-compromised with its complexity and emission controlsor will you switch to a well-engineered petrol motor from someone like Honda or Toyota perhaps? And if so, do you have any recommendations for those of us who are similarly weary of Euro5 and Euro 6 diesels?

Thanks again for the feedback. Both my 1.9 PD 105hp and 2.0 CR 140hp are still pulling brilliantly and gives me fantastic mpg by any standarts, so I guess that's a good sign. My 1.9 PD has 128k on the clock and I bought it with 69k. It's always had oil changed at 10k and for the last ~5000 miles I only use Shell Nitro diesel and intend to do that going forward (it gives about 3% more mpg so not much extra cost). My 2.0 CR was bought at 88k and now has 90k and I'm changing oil every 9k (not 18k as per book schedule) and I only use Shell Nitro in that one as well. So I guess I might ask the garage to check EGR at next services to see if it needs attention. I try to reach 4000rpm in 2nd + 3rd each week after the oil temp has reached ~90C+ and when I do long trips (50+ miles and I think this happens regularly enough) I do this various times during such journeys. It's funny the 1.9 PD has a tendancy to blow black smoke the first time you do ~4000rpm after it's been driven slowely for a week or more, but then it dissapears quickly again.

Cheers