Diesel car engines

[casstony]

We learned a bit about diesel engines the hard way recently. My sister's Ford Territory cracked an injector - price of the part only from Ford was $1500. A few weeks later at 100,000km an EGR valve broke - price of the part only from Ford was nearly $1600.

I talked to a couple of independent mechanics and the jobs can be done much cheaper but they also recommended running a cleaner through the injectors and then another cleaner to remove carbon build-up from the EGR valve and cylinders. I had that done on my Territory today and they showed me a video of enormous plume of smoke exiting the exhaust.

I've got a clean engine now but I think there are too many pollution issues associated with diesel for it to be used as a car fuel. There should be a ban on the sale of new cars with diesel engines.

[CeratodusDuck (George)]

Nulon Diesel Turbo Cleaner (pro-strength) - ONLY one that works PROPERLY. Ford wanted close to $2500 to fix my Mk4 Mondeo that had a slight "buck" under load or rapid acceleration. ONE bottle of the stuff mentioned and 200km driving later, and not only did it cause DPF regen , but cleaned off all the carbon crudding the system. It now goes perfectly again, and the fuel economy is back to what it previously was.

Cleans the turbo, EGR, lambda sensors, DPF and injectors. Cost is $26 a can, vs $2500 for Ford to MAYBE fix the issue.

[casstony]

That's interesting George; was the car smoky while the cleaner was in the system?

[CeratodusDuck (George)]

Not that I noticed whatsoever. The car has done 180,000 km as of yesterday, and 900km since the additive.

I am going to put another bottle in at 185000.

[muletopia (Chris)]

We have three one ton Isuzu utes


1)1983 model unregistered for farm 680,000 K, had to replace the radiator
this one has had a hard life

2)2003 model registered as farm ute for fire fighter 380,000 Kno problems

3)2018 model only had it for a year no problems, it is our use for everything vehicle,
we don't have a car. It is a snap for carrying a 21 ft long double kayak

We also had a 1981 diesel Gemini with 500,000 k on the clock, it was good until it was stolen and destroyed.


So the reliability of small diesels seems to be OK


Chris

[casstony]

I expect older diesels were less likely to have problems due to the lack of pollution control devices.

[Gary47 (Gary)]

I am a retired diesel mechanic. You will find good and bad in any product and diesels are no exception. Most of the problems with diesel engines in small vehicles come down to the manufacturers trying to make them perform like a petrol engine, pull like a tractor, run on the smell of an oily rag and meet pollution requirements all at the same time. They reduce the capacity and boost intake pressure to levels that would have seemed insane not too long ago to increase performance and improve fuel economy and add EGR and CAT Converters to reduce pollution. Common Rail Injection is a recent innovation that addresses all of the above requirements and all of these innovations are potential sources of problems. They all inter-react and a small problem can quickly turn into an avalanche.
Add to the previous the drive to reduce the weight of every component and I think you will begin to appreciate that diesel engines in cars are not the almost bullet proof units that earned diesel engines a reputation for reliability.

[GrahamL]

Do you think the above additives are helpfull Gary ?

[Gary47 (Gary)]

I have never used them. Only used manufacturer approved products. But I was working with much larger units where mistakes cost real money.
A lot of products are promoted by people with a vested interest. A lot of the perceived benefits are wishful thinking. If your engine produces a cloud of smoke after you add a product to the fuel is that pollution being cleared out of the motor or just what you added being burned? What is it doing to your expensive Cat Converter? Does the supplier give a cast iron guarantee that he will make good any damage caused?
To dislodge any buildup in the motor the additive would have to contain volatile aromatics to dissolve the build up or increase combustion or exhaust system and EGR system temperature. What is that going to do to your motor if there is any residue in the fuel when you are driving?
I think the question you really need to ask is "Why does the engine need this product" Using additives is just like putting a band aid on a broken leg. The band aid won't last long and you still have a broken leg.
Most injector problems are caused by fuel contamination. Do you always use reputable fuel or do you fill up at the servo that is always cheapest.
Do you use genuine fuel filters or after market?

[GrahamL]

Why does the engine need this product

That is something I often wonder , catch cans come to mind been round forever they are cheap if these do what you read why dont the makers fit them , warrenty claims would drop surely and the carmaker makes more dough ?


I have one of the last KUN26 running in my hilux 2wd

I'm around 140k now toyota says replacing the injectors would be prudent some services back I havnt done them yet but will soon I guess .
At probably around 2k i get how many of us get a little reflux at the thought and look for a temp fix.



From what I read most all common rails are fussy beasts Chris

the older engines just kept on rolling I had a friend with an old troopy he sold it at 400 and believe it was still plugging along at plus 600 .

[casstony]

Originally Posted by Gary47

"Why does the engine need this product"

You answered that question earlier Gary. It seems all modern diesels are likely to have problems at relatively low km's, due to the anti-pollution devices.

I had noticed that my Territory's average fuel consumption had risen from about 8.2 to 8.8 over the last 5 years - curious to see if that drops back down.

Apparently chemical carbon cleaning has been done on trucks for many years?

[Gary47 (Gary)]

I think it's getting much harder to make a case for small diesels in cars. Price of diesel and much improved fuel economy in petrol engines and higher servicing costs mean there really is no substantial difference in running costs.
The one thing that diesels excel at is working under load. If you needed to tow a load a diesel was the best choice but the modern small diesels are made so light with a high Aluminium content that they frequently cannot tolerate the higher thermal output generated by towing. I used to deal with an engine machine shop in Melbourne. Last time I was in his shop he had a stack of Toyota KD engines a horse could not jump over, all waiting to be rebuilt, all failed due to overheating.
So if they are no cheaper and don't tolerate heavy loads what is the point?
Perhaps you like the smell of diesel on your hands after you fill up?

[glend (Glen)]

The problem with modern diesel engine design is that they are built like petrol engines today, meaning they are built light, they are built to the generally Euro regs for environmental impact, and they are controlled to make as little noise as possible (meaning pilot injections are used to create slow flame fronts and soften the ignition). They also are usually wrapped in noise suppression covers and under engine shrouds, which retain heat at the expense of lower NVH figures.
In seeking to build them light, modern diesel heads maybe one piece assemblies which are bonded together and cannot ever be rebuilt. Mercedes diesels are a good example of engines which are throw away if anything goes wrong; they have epoxy bonded heads, very thin cylinder walls which cannot be resleeved, and they run hot.
I have driven my old CRD, for 13 years, with no issues at all. It is built by VM Motori in Italy and designed to be a 500,000km engine, with rebuild in mine and all parts still available to repair heads, new liners, etc and it is easy to work on. Over heating is never an issue as it has an engine mgt system that manages shutdown of functions to reduce heat, and I drive to minimise exhaust temps.
Sadly, most people that buy diesels have absolutely no idea how they should be driven, and fang around way above the torque band, over fuelling and generaring heat that destroys the engine. Modern diesel cars don't come with Exhaust Gas Temperature gauge, which is the most important instrument you can have.
I have travelled extensively through the outback, and constantly see people do stupid things to diesels. If you don't know how to drive a diesel, don't buy one and then spend years complaining or seeking remedies from the manufacturer for your stupidity.

[leon]

Glen, I have read all of this thread with great interest, and also drive a diesel 2.8 turbo Colorado which is now 5 years old and has done some 90,000 k's.

Its main job is to pull a caravan around Australia most of the time, which it dose quite well and fingers crossed I have had no major issues with it.

It is always serviced at the recommended intervals at the Holden dealer ship that sold it, however I did the last 90k service myself and found they could not be trusted to do the job.

They were very incompetent in their approach to the work that was suppose to have been carried out and missed a lot of important stuff and I have absolute proof of this, at least i know the filters and other jobs were carried out according to the service manual when I did it myself. I know this is a bit off track and has nothing to do with the initial post, but i thought i would just throw that in.

Glen I read your last post on the the way people drive there diesel vehicles and you see stupid things from some drivers, what do you mean by that please.

I never flog my rig when towing or otherwise and drive at about 90ks in a gear not making the engine work to hard with good rev's.
It seems to manage very well then and the temp is sitting quite low.

Of coarse there are times when it has to work a bit harder when climbing some steep hills for example and gets a bit hotter, but soon settles again once on flatter black stuff.

So Glen what is a stupid way of driving a diesel, this is not meant to be a trick question or be offensive, but i am truly inquisitive and interested to know.

Thanks for that in advance.

Leon

[Gary47 (Gary)]

The two common problems small modern diesels commonly suffer from are as Glen pointed out, high exhaust temperature and also insufficient cooling capacity. If you have a pyrometer fitted and watch it as you start to climb a hill carrying any sort of load it is scary how fast the exhaust temp goes past the safe limit into turbo destroying territory. A turbo will only take so many over temp cycles before it starts to shed or erode blades. When climbing a hill with a load the normal tendency is to keep full throttle and downshift as required when speed drops. That technique will have your exhaust valves cherry red and the turbo screaming for mercy. Reducing the throttle is the only thing that will keep the temperature down. That means that you have to use a much lower gear.
The second problem, inadequate cooling is caused by manufacturers trying to make the engine as small and light (and cheap ) as possible while still putting out high horsepower. To achieve that the cylinder heads are made as compact as possible but the inlet and exhaust ports are as large as possible resulting in reduced coolant passage size within the head, add in the extra restrictions caused by having 4 valves per cylinder and you find that many cylinder heads have "dead spots" where there is restricted flow and so you get local hot spots where the coolant can boil and cavitation occurs leading to cracking and erosion problems.
Of course neither of these problems is obvious to the driver, the coolant temperature gauge sensor is far enough away from the problem areas that it does not register an overheat condition and none of the small diesels that I have seen monitor exhaust gas temperature as part of their engine management system.

[Peter Ward]

Originally Posted by casstony

......

I've got a clean engine now but I think there are too many pollution issues associated with diesel for it to be used as a car fuel. There should be a ban on the sale of new cars with diesel engines.

So, let me get this straight.

Because you have had mechanical problems with your Ford and put a cleaning additive into your tank, that caused sooty emissions you think diesel powered vehicles should be banned?

Not all diesel vehicles are created equal.

My diesel car has both a particulate filter and a Diesel Emissions Fluid (DEF) tank (commonly labeled as AdBlue). Its basically a second tank filled with urea and distilled water, which is injected into the catalytic converter. By doing so the emissions are reduced by the ammonia into water and nitrogen. Both of which are harmless.

Being a lean burn cycle, diesels also emit less CO2 than petrol engines.

The DEF tank is good for about 6000km of driving before it needs topping up again, at a cost of about $20

If fact a recent University of Montreal study concluded the emissions from MODERN diesel engines are far less of a concern than petrol driven engines.....hence the notion of banning diesels based on, what I can only conclude is opinion, rather than fact, I have to seriously question.

[casstony]

I'll entertain the possibility that I'm wrong Peter, even though it's never happened before

I was under the impression that diesel couldn't match petrol emissions even with the latest anti-pollution gadgets - that's what the whole VW engine scandal was about. Add to that the lower reliability of modern diesel car engines and petrol seems like a no-brainer?

[Peter Ward]

Originally Posted by casstony

I'll entertain the possibility that I'm wrong Peter, even though it's never happened before

I was under the impression that diesel couldn't match petrol emissions even with the latest anti-pollution gadgets - that's what the whole VW engine scandal was about. Add to that the lower reliability of modern diesel car engines and petrol seems like a no-brainer?

Maybe you need to look at a different class of car.

My previous E-class Benz was an oil burner, pulled like a train and never had a single mechanical issue or puff of black smoke from it in 6 years I owned it. My current oil burner is a Range Rover, only had it a year, but unsurprisingly has not missed a beat.....and comes in well under the latest Euro emissions standards.

[DarkArts]

Originally Posted by casstony

I was under the impression that diesel couldn't match petrol emissions even with the latest anti-pollution gadgets - that's what the whole VW engine scandal was about.

That was two engine generations ago. Your information is outdated and patchy. VW tried to meet emissions and economy targets (while achieving advertised power) purely through tuning, and couldn't. Later engines (EU6 and EU6plus) have Selective Catalytic Reduction (SCR) - AdBlue as it is commonly known - to reduce NOx emissions and can therefore use more reliable tuning without the need to "cheat".

The last AdBlue fill up cost me 90c per litre and 10L lasts about 8000km.

Modern petrol engines consume more fuel, emit greater CO2 per km and have higer particulate emissions. The latest emissions standard in Europe calls for Petrol Particulate Filters (PPF) to bring particulates down to the same level as modern diesels.

Add to that the lower reliability of modern diesel car engines and petrol seems like a no-brainer?

I'd love to see where this comes from. Where is the evidence?

My TDI is EU6 compliant. It's the best car I've ever driven. The engine management system constantly monitors exhaust gas temperature (amongst hundreds of other parameters) and limits fuel injection when temperature thresholds are reached (i.e. de-torques the engine) but I've never noticed a loss of power like that. The car achieves 20% less fuel use over the modern petrol it replaced (which was no slouch) yet is 30% heavier (it's a larger car).

DPF re-generation occurs every 250-300km in my car. There is a correlation between the "quality" of regen and fuel economy. After a high-speed highway drive, during which a regen occurred, I noticed an immediate improvement in fuel economy (about 7-8% compared to the long-term average). Regens around town are OK but not quite as effective. Still, that meets my needs well and I'm very happy.

[leon]

Ok Gary I read your post, so what happens now, seeing that i am one of millions of diesel drivers that do know how to look after their vehicles.
Do I just wait till it falls apart or is there a magic trick available to help this not happen.

Leon