Diesel engine query

Road-Hog · 06-09-2014 7:10am #1

I've heard a good number of people recently (none of whom are in the motor trade)say that the newer type/ generation of Diesel engines i.e those from 2011/12 onwards are not good for 250,000 miles plus like their predecessors were, 150,000miles being a more realistic expectation. Can anyone verify if there is any truth in such rumours.

Bpmull · 06-09-2014 9:16am

I wouldn't really say there is any truth in that at all. As it all depends on how well it's maintained and how it's driven. There was probably less to go wrong on older diesel as they had no dpf or dmf etc. but then realistically any car can do any mileage it's just about when it becomes uneconomical to repair it. So even a newer diesel that's well minded used for its purpose ie not just driven around town Is capable of going for more than 150k miles.

jprboy · 06-09-2014 11:13am

Some say it's built-in obsolescence:

the policy of deliberately limiting the life of a product in order to encourage the purchaser to replace it

http://www.thefreedictionary.com/Built-in+obsolescence

Doesn't just apply to cars

derry · 06-09-2014 9:16pm

Deisel manufactuers changed the Diesel fuel formula and it now makes the diesel engines wear out faster .They now in some engines recycle the exhast fumes back into engine for reburn ad get better MPG with that but it has some negative effects .The old diesel formula fuel was 100% diesel fuel.The old engines were not common rail worked at lowwer fuel pressure in the injectors and the injectors would fire once per 2 revolutions of piston of that engine .The fuel did not burn fully and the excess fuel gave a lot of extra lubrication to the pistons and valves and so forth ..The newwer diesel fuel has ~7% bio fuel in it .This is because the old diesel fuel had high sulfer content which the new Particle filters can not handle .Removing the sulfur removed lubrication of the Diesel fuel for the fuel pumps .To put lubrication back into the diesel fuel required adding the 7% bio fuel. However the bio fuel does not have anything like as good a lubrication quality so parts wear out faster .Changing to old diesel such as red diesel would result in wrecking the Particle filter. The engines now often fire several small injections into piston rather than one to get better burn and better MPG and the extra lubrication to pistons is lost similar to petrol engine which burn dry and results in faster wear of pistons .The Bio fuel often gets corrupted if it is heated up .In heavy city traffic the diesel fuel goes into common rail and most fuel is heated up in the common rail above the not engine and as fuel demands are low the most the hot fuel will return to tank .The hot corrupted Bio fuel wrecks the engine faster .If driving always on motor ways the majority of the fuel is burnt up and the bio fuel corrupted issue is looking to be less likely.When fuel is burnt in the engine some 80% the fuel is ejected into the exhaust stack .Some diesel engines will take this hot still burning in the exhaust stack fumes and put it back into the engine to add extra fuel to it and return it .This results in better MPG but hot burning fuel is hard in engine parts and the lubrication qualities of the fuel. So the short reply to this is there looks to substantial evidence that modern diesel engines will on average have a much reduced life span .Also for city driving they look to be disaster . Good luck the new petrol cars are returning very good MPG with the more likely better results in lowwer service costs .They took the wonderful 1990 era diesel solutions which could do 500,000 miles easy and killed it dead .

Derry

Stella Virgo · 06-09-2014 9:35pm

^^^^^^
any chance you might use paragraphs the next time....;)

corglass · 06-09-2014 9:42pm

People love to complain about modern diesels. Granted they have their issues, but let's not forget the positive. Immense toque and great mpg in 'heavy' modern cars.

If you're doing any half decent mileage and willing to service them properly yourself they're a pleasure and will easily do 250k km +

ytareh · 06-09-2014 10:19pm

Stella Virgo wrote: »

^^^^^^
any chance you might use paragraphs the next time....;)

Thanks for the very informative post Derry .

George Dalton · 07-09-2014 9:02am

corglass wrote: »

People love to complain about modern diesels. Granted they have their issues, but let's not forget the positive. Immense toque and great mpg in 'heavy' modern cars.

Exactly!

People like to get all misty eyed talking about the good old reliable diesels from years ago but the fact is that the game has moved on massively since then and these days nobody would actually be willing to put up with a noisy, smokey, underpowered diesel engine that needs servicing every 6k miles, no matter how reliable it was.

kermitpwee · 07-09-2014 11:37am

George Dalton wrote: »

Exactly!

People like to get all misty eyed talking about the good old reliable diesels from years ago but the fact is that the game has moved on massively since then and these days nobody would actually be willing to put up with a noisy, smokey, underpowered diesel engine that needs servicing every 6k miles, no matter how reliable it was.

I wouldn't agree with that George, there is still a market for these older reliable diesels. The service interval on modern diesels is way too long imo. No offense George intended.

HandsomeDan · 07-09-2014 12:00pm

derry wrote: »

Deisel manufactuers changed the Diesel fuel formula and it now makes the diesel engines wear out faster .

So FOS.

Are you Jim Corr by any chance?

OP, a modern diesel will easily do 150k miles ffs

quadrifoglio verde · 07-09-2014 12:05pm

While modern diesels will do the high milage, the liklihood of them breaking the 250k mike barrier is reduced on the newer ones compared to the ones of yesteryear.
While a dmf replacement is overly expensive on a five year old car relative to the value of the car, a dmf replacement on a 12 year old car more than likely is.

Markcheese · 07-09-2014 12:08pm

In someways should we be looking at the wholelife cost of the engine, old diesel engine lots of servicing and more fuel and dirty (smokey) but long life.
Modern one needs less servicing,and less fuel but more bits to repair long term (dpfs,injectors,dmfs,ect)
Look at trucks and tractors ect. to see the trend, they're all modern engines because it's fuel use that counts.

Bang_Bang · 07-09-2014 12:21pm

jprboy wrote: »

Some say it's built-in obsolescence:

the policy of deliberately limiting the life of a product in order to encourage the purchaser to replace it

http://www.thefreedictionary.com/Built-in+obsolescence

Doesn't just apply to cars

Correct, we do it where I work, 10 years ago the realisation that our products were too good, so we redesigned them to die after a certain amount of cycles. I'ts common practice these days in modern manufacturing and actually it's a philosophy of some quality guru's. The Japanese use a different quality philosophy than the west.

Getting back to the Diesel, I think derry is right there, I could never understand why the old 1.9 TDi was removed by VAG, now I know, it lasted too long and was very reliable. I knew a guy who had an Audi 80 1.9 TDi and he had over 450,000 miles on it and the last I heard he was still driving it.

Galwayguy35 · 07-09-2014 12:27pm

What's classed and an older diesel engine?

Mine is a 2004 TDI Golf, I'm at 186 k and am hoping to reach and even pass the 250 k mark if I can.

I've replaced the clutch and gearbox but the engine is running like a top, never gave any trouble at all.

Cleveland Hot Pocket · 07-09-2014 12:31pm

corglass wrote: »

People love to complain about modern diesels. Granted they have their issues, but let's not forget the positive. Immense toque and great mpg in 'heavy' modern cars.

If you're doing any half decent mileage and willing to service them properly yourself they're a pleasure and will easily do 250k km +

Really?
Diesel MPG (real world, not manufacturer figures) haven't increased much in the past 10 years.
A mark4 diesel golf will easily top 55-60 mpg on an extra-urban cycle. I know because I had a 2001 diesel golf and it did those figures on motorway drives. My 2010 skoda superb TDI with supposedly modern technology, low emissions, chape tax etc only did 3-5 mpg at a push more.

Add in that, to get that small increase in MPG, we've had to put up with many new anti-emissions crap like DPFs, and running on ultra high compression and stressing the engine more to reduce life. I've seen 10-15 year old vag cars with 500k miles+ - can't see many modern diesels reaching that.

Even the old jap diesels were better - if less economical. I've a 95 diesel carina outside with 425k miles on the clock which will do 45 mpg easily, and on pretty much anything flammable that can be found.

HandsomeDan · 07-09-2014 12:34pm

Bang_Bang wrote: »

Correct, we do it where I work, 10 years ago the realisation that our products were too good, so we redesigned them to die after a certain amount of cycles. I'ts common practice these days in modern manufacturing and actually it's a philosophy of some quality guru's. The Japanese use a different quality philosophy than the west.

Getting back to the Diesel, I think derry is right there, I could never understand why the old 1.9 TDi was removed by VAG, now I know, it lasted too long and was very reliable. I knew a guy who had an Audi 80 1.9 TDi and he had over 450,000 miles on it and the last I heard he was still driving it.

450k in that thing, the poor guy. The 1.9 TDi was replaced because, by modern standards, it's a crappy engine.

Manus compete against one another. if they don't update long in the tooth products they wont' stay in business. Simples.

Bang_Bang · 07-09-2014 12:38pm

HandsomeDan wrote: »

450k in that thing, the poor guy. The 1.9 TDi was replaced because, by modern standards, it's a crappy engine.

Manus compete against one another. if they don't update long in the tooth products they wont' stay in business. Simples.

Neigh say anyone I know that owned one. I remember some guys I work with complaining that the 2008 2.0 VAG Diesel was a pile of crap compared to the 1.9 TDi. i'm not a mechanic so I don't know why, but I remember loads of debating over it during lunch hour.

corglass · 07-09-2014 1:38pm

Best diesel engine of the last 20 years guys? All things (mpg, reliability, ease of maintenance, power etc.)

2.0 Toyota diesel (1993-1997)
2.0 TD Toyota (1997-2001)
1.9 VAG (pre 2001)
1.9 TDI (post 2001)
2.0 TDI (post 2005)
Any other contenders?

Cleveland Hot Pocket · 07-09-2014 2:42pm

You're forgetting a few great diesels, the famous ford 7.3 v8 diesels (both IDI and powerstroke), the chevy 6.2 detroit diesel to name but two.
Also the 2.0 TDI should not be on a great engine list!

dgt · 07-09-2014 2:58pm

XUD
Fiat/Sofim diesel
Mercedes OM series
Cummins BT series

Real diesel engines I'll probably get shot down for by dimwits who haven't a clue :rolleyes:

Markcheese · 07-09-2014 3:38pm

Weren't most of those engines dropped because they couldn't hit emissions standards... Also modern cars are getting bigger and heavier with more safety gear as well as creature comforts, more weight means juice needed to push it along...
Also we're driving faster, (well I am ) with a lot more dual carraigeway /motorway kms...
I use way more fuel per km driving on motorways than I do on regular N roads at 80/90 kph ...
Would we put up with the performance from an old 2 litre straight diesel ...as opposed to a modern yoke...

Cleveland Hot Pocket · 07-09-2014 3:49pm

Markcheese wrote: »

Weren't most of those engines dropped because they couldn't hit emissions standards... Also modern cars are getting bigger and heavier with more safety gear as well as creature comforts, more weight means juice needed to push it along...
Also we're driving faster, (well I am ) with a lot more dual carraigeway /motorway kms...
I use way more fuel per km driving on motorways than I do on regular N roads at 80/90 kph ...
Would we put up with the performance from an old 2 litre straight diesel ...as opposed to a modern yoke...

Aside from the sound, there was not much performance difference between my straight diesel '95 carina and my '10 Superb TDI.
I don't think that these "advances" are as widespread as you and others think!

Yes, modern diesels can do well in a fake staged emissions test but in the real world it's not happening mate.

IMO.
I mean the build quality has improved a lot with impact protection, rust protection IMO and so on, but it's not an mpg improvement

Gazzmonkey · 07-09-2014 3:50pm

corglass wrote: »

Best diesel engine of the last 20 years guys? All things (mpg, reliability, ease of maintenance, power etc.)

2.0 TDI (post 2005)

VAG 2.0L PD TDI ??

Supposed to be a terrible engine, but they replaced it with a 2.0L CR TDI engine around 2008, much better engine.

Markcheese · 07-09-2014 4:02pm

Would a diesel hybrid be a goer, the engine wouldn't have to be responsive, the electric motor could do the acceleration ... Just a good steady plodder-getting fuel efficiency and low emissions...or would it be too pricey ..

Cleveland Hot Pocket · 07-09-2014 4:05pm

Gazzmonkey wrote: »

VAG 2.0L PD TDI ??

Supposed to be a terrible engine, but they replaced it with a 2.0L CR TDI engine around 2008, much better engine.

Still not worthy of a great diesel engine list!

Markcheese wrote: »

Would a diesel hybrid be a goer, the engine wouldn't have to be responsive, the electric motor could do the acceleration ... Just a good steady plodder-getting fuel efficiency and low emissions...or would it be too pricey ..

I'm amazed that there's been no diesel electric offered yet. In theory it is the most economical use of the fuel. Diesel generator to supply electricity to power the wheels and charge the battery. Combined with a kinetic energy harvesting system, over 100 mpg could well be possible!

bazz26 · 07-09-2014 4:49pm

Isn't the Citroen DS5 available as a diesel hybrid?

MuppetCheck · 07-09-2014 5:00pm

Gazzmonkey wrote: »

VAG 2.0L PD TDI ??

Supposed to be a terrible engine, but they replaced it with a 2.0L CR TDI engine around 2008, much better engine.

Some versions of the 2 litre were fine bar the injectors and even then I don't think it affected all versions either but they probably weren't sold in high numbers here - 2 litre Mark V's, Leons, Alteas etc.

The CR version is probably one of the most reliable diesel engines out there at the moment.

Markcheese · 07-09-2014 7:27pm

http://www.psa-peugeot-citroen.com/en/content/hybrid4-technology-diesel-hybrid-engines-psa-peugeot-citroen-0

Peugeot 3008 and Citroën c5
Seems like a practical idea but no idea how good it is and they don't seem to be trumpeting it's fuel efficiency or low co2 figures ,
Kind of surprised it's a hdi engine though it might be the old non turbo yoke ...

HandsomeDan · 07-09-2014 9:29pm

Markcheese wrote: »

http://www.psa-peugeot-citroen.com/en/content/hybrid4-technology-diesel-hybrid-engines-psa-peugeot-citroen-0

Peugeot 3008 and Citroën c5
Seems like a practical idea but no idea how good it is and they don't seem to be trumpeting it's fuel efficiency or low co2 figures ,
Kind of surprised it's a hdi engine though it might be the old non turbo yoke ...

HDi is the PSA CR engine.

Chimaera · 07-09-2014 10:16pm

Cleveland Hot Pocket wrote: »

Aside from the sound, there was not much performance difference between my straight diesel '95 carina and my '10 Superb TDI.
I don't think that these "advances" are as widespread as you and others think!

Yes, modern diesels can do well in a fake staged emissions test but in the real world it's not happening mate.

IMO.
I mean the build quality has improved a lot with impact protection, rust protection IMO and so on, but it's not an mpg improvement

There's the thing though.

Modern cars weigh much more than old ones. They have lots of accessories that draw power from the engine (aircon, etc). They're also saddled with emissions control systems that frequently hurt fuel economy.

Yet for all that they're equalling or bettering the economy of diesel cars from 20 years ago. So yes, the modern diesel engine is a far better thing than its ancestor.

Chimaera · 07-09-2014 10:45pm

derry wrote: »

Deisel manufactuers changed the Diesel fuel formula and it now makes the diesel engines wear out faster .They now in some engines recycle the exhast fumes back into engine for reburn ad get better MPG with that but it has some negative effects .The old diesel formula fuel was 100% diesel fuel.The old engines were not common rail worked at lowwer fuel pressure in the injectors and the injectors would fire once per 2 revolutions of piston of that engine .The fuel did not burn fully and the excess fuel gave a lot of extra lubrication to the pistons and valves and so forth ..The newwer diesel fuel has ~7% bio fuel in it .This is because the old diesel fuel had high sulfer content which the new Particle filters can not handle .Removing the sulfur removed lubrication of the Diesel fuel for the fuel pumps .To put lubrication back into the diesel fuel required adding the 7% bio fuel. However the bio fuel does not have anything like as good a lubrication quality so parts wear out faster .Changing to old diesel such as red diesel would result in wrecking the Particle filter. The engines now often fire several small injections into piston rather than one to get better burn and better MPG and the extra lubrication to pistons is lost similar to petrol engine which burn dry and results in faster wear of pistons .The Bio fuel often gets corrupted if it is heated up .In heavy city traffic the diesel fuel goes into common rail and most fuel is heated up in the common rail above the not engine and as fuel demands are low the most the hot fuel will return to tank .The hot corrupted Bio fuel wrecks the engine faster .If driving always on motor ways the majority of the fuel is burnt up and the bio fuel corrupted issue is looking to be less likely.When fuel is burnt in the engine some 80% the fuel is ejected into the exhaust stack .Some diesel engines will take this hot still burning in the exhaust stack fumes and put it back into the engine to add extra fuel to it and return it .This results in better MPG but hot burning fuel is hard in engine parts and the lubrication qualities of the fuel. So the short reply to this is there looks to substantial evidence that modern diesel engines will on average have a much reduced life span .Also for city driving they look to be disaster . Good luck the new petrol cars are returning very good MPG with the more likely better results in lowwer service costs .They took the wonderful 1990 era diesel solutions which could do 500,000 miles easy and killed it dead .

Derry

Man, I could smell the stink of bull$hit off this post a mile off.

First off, the fuel standards used here are set by CEN, a body that specialises in standards. The standards are devised by CEN in consultation with governments and industrial stakeholders. In the case of fuel standards the main stakeholders are the DFIE manufacturers and the fuel suppliers.

The main changes made to fuel standards in the last 20 years have involved the removal of sulphur compounds from diesel to reduce the emissions of sulphur dioxide into the atmosphere. SO2 is a significant contributor to acid rain, so its removal is a good thing.

There was a downside in that sulphur helped with the lubricity of the fuel. That lubricity had to be added back in, and the standard revision that eliminated sulphur from diesel also continued to mandate a specific level of lubricity: the fuel manufacturers had to find additives to maintain the lubricity level. Interestingly the best lubricity enhancer that can be added to diesel is biodiesel, which is mandated through the biofuels directive.

Exhaust Gas Recirculation is used to reduce combustion temperatures, which reduces the formation of NOx emissions. Again, a significant culprit for acid rain. In the past EGR was problematic because older diesel engines were sooty. This coupled with crankcase ventilation systems which routed back to the engine's intake often resulted in a gunky mess blocking up the intake. Interestingly, removing sulphur from the fuel substantially reduced soot output too.

Diesel engine query

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