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nissannewby
19th June 2012, 11:23 PM
Hey all

I have noticed lately there have been a few posts about smoke from diesels etc the colours and all that and what it means so i thought i would post up this link to help all those looking for a bit of info.

http://www.dieselsmoke.com.au/

The information below has been taken from the link above, have a read. feel free to go to the link as there are a number of other links embedded there also

FYI

Diesel Smoke tells YOU a Story

Basically, smoke from a diesel engine indicates that something is not right.

It should be taken as an indication that there is a problem existing (or developing), that will potentially shorten the engine life, or result in unnecessary costs. It should be regarded as an opportunity to take measures that will save you money in both the long term and also the short term. At the least, that smoke may be due to a simple problem, that is causing poor combustion efficiency…and costing you in excessive fuel bills (eg carboned up engine from excessive idling, stop start operation or short run times). At the other end of the scale, it may be your last chance to act, before a catastrophic engine failure occurs (eg piston seizure, valve or turbocharger failure).

A diesel engine in good condition should produce no visible smoke from the exhaust, under most operating conditions. A short puff of smoke when an engine is accelerated under load may be acceptable, due to the lag before the turbocharger speed and air flow is able to match the volume of diesel injected into the cylinders. That would only apply to older technology diesel engines, but with modern type diesels, no smoke at all should be evident.

There are three basic types of diesel smoke, identifiable by their colour... Black, Blue and White

In the outlines below we explain what causes each colour of diesel smoke and provide you with links to high quality products that will help you solve these problems....

Black smoke is the most common smoke emitted from diesel engines. It indicates poor and incomplete combustion of the diesel fuel. There are many causes, including…
Incorrect timing
Dirty or worn injectors
Over-fuelling
Faulty turbocharger (ie not enough air to match the fuel)
Incorrect valve clearance
Incorrect air/fuel ratio
Low cylinder compression (eg sticking piston rings or worn components)
Dirty air cleaner
Restricted induction system (eg system too small or kinked inlet piping)
Other engine tune factors
Poor quality fuel
Excessive carbon build up in combustion and exhaust spaces
Cool operating temperatures

Obviously, worn or damaged components must be replaced, and the earlier you identify and fix the problem, the less damage will be done. Keep on top of engine tune issues, including valve adjustments, and regular servicing of air, fuel and oil filters. Do not buy fuel from suspect outlets. Dirty components, such as injectors can be easily restored to full cleanliness by using an effective and reliable fuel system cleaner. If you choose from our range of products, Cleanpower is what you need.

Cleaning of internals of engines has usually only been possible at overhaul, however, Cost Effective Maintenance provide two products to enable vehicle and equipment owners to quickly, safely and cheaply restore full cleanliness to combustion and exhaust spaces (FTC Decarbonizer) as well as piston rings, oil pumps, oil galleries, oil coolers, piston skirts, valve gear, etc (Flushing Oil Concentrate).

Black smoke is high in carbon or soot, which is an undesirable product of diesel combustion. Now, the combustion of diesel is a complicated process of breaking down the various hydrocarbon fuel molecules into progressively smaller and smaller molecules, by burning in the presence of oxygen. The main and ideal end products of combustion are CO2 and H2O (carbon dioxide, the greenhouse gas and water). It is believed that the last step in the process is carbon monoxide (the poisonous gas) to carbon dioxide. This is also the slowest step by far, and when combustion conditions deteriorate some upstream bottle necking occurs in the chain of combustion reactions. This results (according to some authorities) in polymerization of smaller partly burnt molecules into much larger ones, which become visible as soot, or black smoke.

Blue smoke is an indication of oil being burnt. The oil can enter the combustion chamber for several reasons.
Worn valve guides or seals
Wear in power assemblies (ie cylinders, piston rings, ring grooves)
Cylinder glaze
Piston ring sticking
Incorrect grade of oil (eg oil too thin, and migrating past the rings)
Fuel dilution in the oil (oil thinned out with diesel)
At cold start, blue smoke is often evident, and can reflect reduced oil control, due to fouling deposits around piston rings or cylinder glaze (which is actually carbon deposited in the machined cylinder crosshatching. These tiny grooves actually hold a film of oil, which in turn completes the seal between the combustion chamber and the oil wetted crankcase). Blue smoke should not be evident at any time, but it is worth noting, that engines with good sound compression can actually burn quite a lot of oil without evidence of blue smoke. Good compression allows oil to burn cleanly, as part of the fuel. It’s not good though!

Once again, restore physical cleanliness to all components. Replace worn parts where necessary. In some situations, where the engines are pretty worn, but you just need to keep them in service, cleaning with the previously mentioned products, followed by effective additional anti-wear protection, will reduce internal stresses on all those tired components, providing extended service life. Our AW10 Antiwear

White smoke occurs when raw diesel comes through the exhaust completely intact and unburned. Some causes of this include…
Faulty or damaged injectors
Incorrect injection timing (could be a worn timing gear or damaged crankshaft keyway).
Low cylinder compression (eg caused by leaking or broken valves, piston ring sticking, cylinder and/or ring wear, or cylinder glaze)
When white smoke occurs at cold start, and then disappears as the engine warms up, the most common causes are fouling deposits around piston rings and/or cylinder glazing. Use of our Flushing Oil Concentrate and FTC Decarbonizer address these respective problems.

Water entering combustion spaces will also create white smoke. Faulty head gaskets and cracked cylinder heads or blocks are a common cause of water entry, and are often to blame. Unfortunately, expensive mechanical repair is the only proper solution here.

Check the link at the top to find out more about Cost Effective's Diesel Smoke Solutions

MudRunnerTD
20th June 2012, 12:44 AM
Good info NewbyGuru lol expanded it for you mate

Maxhead
20th June 2012, 08:08 AM
Funny that because when I bought my new rig it has always smoked black smoke from day 1(only a little at starts and big acceleration)compared to my old '08 model which never smoked at all, but the power difference is huge. The new one has heaps more go in it, lots more power and torque..its a rocket!!!
So I thought black smoke is good :)

nissannewby
20th June 2012, 08:31 AM
A little is good but if you cant see the rear of car from black then you may have an issue if you have an egt gauge your temps will get higher quicker the more black smoke comes out the back.

AB
20th June 2012, 09:08 AM
Good post mate, should help a lot of people out for sure!

growler2058
20th June 2012, 10:07 AM
Ive made it a sticky cheers for the post

Finly Owner
22nd June 2012, 11:46 PM
TOP POST!!!!


Fantastic INFO!

I bow to You!




Tim

Bigrig
23rd June 2012, 07:12 AM
Yeah, top post champion!!!

OhBugger
14th August 2012, 07:49 AM
Thanks for the info!
Any idea's on how to combat the low fuel quality? Are there recommended additives?

threedogs
14th August 2012, 08:21 AM
I thought that was the case, no smoke unless under load. Could always tell when fellow it front about to gun it, little puff and away.
Used to race unlimited M/Cs and same with a good 2 stroke, shouldn't blow smoke

oilpond
14th October 2012, 12:46 AM
Thanks mate!

MEGOMONSTER
14th October 2012, 08:30 AM
Great read buddy.


Sent from the secret chambers of our secret society, on a secret iPhone, with a secret pin code and eye retina scanning from a secret peep hole, just don't tell anyone OK, cos it's secret........

allan f
28th October 2012, 10:02 AM
My 2011 GU with 40000km on it blows a lot of black smoke umder load .
I tow about 2.5 T .
So much smoke my white dog ends up grey , I think he likes it as he could go to the other side and get away from it .
Always did blow a bit of smoke but more after putting a chip in it

jhon
2nd January 2013, 02:49 PM
Hi everyone
Some time these problems have in old cars and you want to check you fuel tank in your car and check your engine any trusted mechanic.I am not sure about that but you want to do this and get healthy benefit.

zaid-m
15th February 2013, 07:49 PM
Thanks mate, a really useful document, much appreciated.

lachiek
4th March 2013, 07:43 PM
My GQ is so smooth and quiet that without smoke I wouldn't be able to tell my truck is running!

Seriously though, anyone with a GQ 2.8 I've spent a bucket load chasing smoke issues (Inj pump overhaul / new injectors / dyno tune / every guage known to man etc) and it turns out she just wants to smoke. If power is good and fuel eco ok Just live with it.

douglarv
28th March 2013, 08:27 AM
Hmmm... I have only had a diesel for a bit, but have driven them extensively - both tractors and cars and I think I spot a flaw here. Black, Blue and White smoke in quantity is bad, but in cold (like 0 C and below) temperatures there is going to be SOME visible exhaust, when the hot exhaust gases meet the cold ambient air. If I am wrong here go ahead and correct me.

Beni C
1st May 2013, 01:59 PM
Awesome info cheers!! First diesel I have owned so this is real handy to know!

anasaz09
12th June 2013, 03:32 AM
I live in a place were diesel engines are only for old trucks and old pick ups, and every single car that uses diesel engine has black smoke coming out of the exhaust, and when I want to buy a decent car that has a diesel engine I ask my friends and relatives about buying it nearly everyone expects its a shitty car.

also, I have read that diesel engines are more fuel efficient than petrol engines.

scott.a.green
28th August 2013, 10:03 PM
Great piece of info mate. Cheers.

Jimmyboyjr4
29th August 2013, 10:28 AM
The only time smoke is visible from mine is under acceleration at night from the car behind headlights. How much smoke are we talking about here in this document?

Mtiehatten
6th September 2013, 02:58 AM
Thanks, I'd say this also holds for petrol for a large part.

sickshorty
14th October 2013, 10:16 PM
Awesome bit of info there thanks mate.

chipppa
11th December 2013, 11:20 PM
Very helpfull cheers mate

LaurelTurboDiesel
22nd February 2014, 11:54 AM
Nice iformation!

davo82
24th March 2014, 05:46 PM
Great info, will show my mates this!

OFFIGO
20th May 2014, 05:50 PM
Great read. Especially for me never having owned a diesel before.

mojo53
5th September 2014, 04:34 AM
Great post mate very informative, something to remember

BIG-_JOHN
28th October 2014, 10:01 PM
My wife's Nissan is an 05 GU 3l turbo soon due for a 150,000 service. This vehicle blows black smoke but only at start up. No smoke is evident later or under load. Fuel consumption is within normal boundaries (about 10.5 litres/100 kms) and power once turbo kicks in is good.
I haven't read the article yet but does anyone know what may cause this.

Cheers, John

Ben-e-boy
28th October 2014, 10:07 PM
I haven't read the article yet but does anyone know what may cause this.

Cheers, John

So why would you open an informative thread, Not read it, then post a question?

Sharky1
29th October 2014, 06:30 PM
I didn't look at the link but to save a lot of folks from becoming paranoid, I thought I'd shed some actual facts regarding this. I am an ex mechanic although not a diesel mechanic however I do own a patrol diesel & have had a landcruiser diesel before that. I'll try to explain this in a simple manner without getting technical but knowing me, I'll get sidetracked........

Most of that info in the 1st post is true however diesels WILL naturally smoke to some degree & I'll explain why. 1stly, they run off the compression of the motor, not from a spark as such, so not as much of the fuel gets burnt nor does it burn as efficiently as a petrol. Another reason, which goes hand in hand with what I just said, is that oil is a biproduct of petrol. It is extracted during the refining process ie petrol is more refined, hence thinner & has a lower flash point & higher combustion rate. These days they make diesel a little differently but for argument's sake we'll stick with what most people can make sense of.

Smoking diesel is NOT necessarily unburnt diesel. If it were unburnt, it wouldn't smoke. However it is probably more correct to say that it's not fully burnt. However even if it is, every fuel that burns has some sort of carbon output & diesel has a higher carbon output than petrol, therefore will smoke more, especially under load, whereby your accelerator pedal is further towards the floor but your engine isn't revving as high which means you're using more fuel than is being fully burnt. ALL fuels create carbon & the more refined the fuel, the less carbon output, hence less smoke. So yes, a diesel will naturally smoke under load to some extent. It's for this reason that poor fuel quality will make your engine smoke more.

An easy way to test this is to (VERY CAREFULLY), throw a little bit of petrol on a camp fire & see how quickly it flames up & how much smoke it emits. Then throw the same amount of diesel on the same part of the fire & observe again. Then throw the same amount of engine oil on the same part of the fire & see what happens.......more smoke, less flame & will sizzle as it takes time to burn, unlike the petrol which burnt immediately. Remember liquids DON'T burn. Heat turns liquid into gas, which burns. Hence why manufacturers try to get petrol to "atomize" before it hits the compression chamber. The smaller the atoms, the faster the burn, the bigger the explosion, the more power you can create. Diesel is different though & as I stated, not only is it an oilier fuel, the burn process is completely different. If you get some cold diesel & hold a lit match to it, it won't burn. I've heard many people say it will but I've done it & it never has. I'll come back to this point later. So you may ask, why don't I put petrol in my diesel & get more power? Well there are many other differences in the properties between diesel & petrol & I'm trying to keep this simple. The biggest reason though is that petrol is a lot more acidic & corrosive than diesel & doesn't have the lubricating properties that a diesel engine needs to be reliable & long lasting.

Yes, inadequate air intake will cause smoking. Any fuel needs oxygen to burn. Too much oxygen & it will over-rev ("a dieselling effect"). Too little & it will choke & smoke. Hence where the theory comes from of getting more power from a motor is not to give it more fuel as such, but to make it breathe. More fuel means more power ONLY provided it can breathe enough to burn 100% of that fuel which is what efficiency is.

I'll go a little further. A petrol engine gets it's timing by timing when the spark plug emits a spark. Hence why a petrol motor can also smoke if the timing is out although this is rare these days with the quality of fuels. So if a diesel runs off the compression, how is it timed & how does it shut down? A diesel gets its timing by allowing a metered amount of fuel into the engine at the right time. It stops by a shut off solenoid on the fuel/injector pump. If your injectors or pump are worn, your diesel will smoke as the fuel system will let too much diesel into the engine than what it can burn.

The reason diesels get a lot more torque in general but a lot more low down torque is mostly but not completely due to the fact that because diesel will burn purely off the compression & burn at a slower rate, a diesel will hold lower revs & do so under load. The other reason is due to the amount of compression a diesel motor has. Increase your compression ratio & you increase your torque & power outputs. However there is a balance in doing this & maintaining strength of the engine components, which is why when you build a motor to go fast, it must also become stronger ie better quality parts.

You may have heard of a petrol engine "dieseling". This can happen for a few reasons, not just too much air, which can also make your engine stall or flat spot depending on a few factors but we'll leave that for another time. A petrol engine can diesel if you put a lower flashpoint, higher octane fuel in. For example when I was a teenager, I had to mow the lawns one day before I was allowed to play with my mate & his remote control helicopter. As an experiment, we put some liquid nitro into the fuel tank of the lawn mower. About 20 secs later the motor started revving higher than ever & even though I closed the throttle & turned the fuel tap off, it kept running flat out until all the fuel was burnt. How my dad didn't hear it I'll never know but probably best that way for me lol.

As a rule a motor needs 4 things to run. Fuel, spark, air & compression. As previously mentioned diesel needs to be hot to burn due to it's low flash point (the point at which it will ignite). This is why you have glow plugs. Their role is to get the motor started. Your car will have a glow plug timer which heats the glow plugs so that they will ignite the diesel once your motor is running, the compression will be enough to keep it going. Unlike petrol cars, you will probably notice that your diesel runs better when it is hot. There is a myth that diesel engines run better on hot days. This is only somewhat true. Yes they will but the reason a petrol car runs better on cold days is due to the air density. I used to drag race V8's yrs ago & I'd recreate this by adding a stocking full of dry ice into my airbox. It's the same with diesels. They too like air density although not as much as petrol's so they will seemingly run better on hot days, or at least the difference between a diesel on a hot day & a cold day is not as different as a petrol on a hot day compared to a cold day. Anyway, as side tracked as I've got, that is the basics of diesels and the variables on why they can smoke.

BIG-_JOHN
29th October 2014, 09:41 PM
@ Ben-e-boy, I have not read the article from the link provided. I however did read the thread.

Why did you bother to post in such a negative way? I have sent thousands of posts in other forums and this is the first time I have had to put up with crap like that. I thought I asked a reasonable question.
Rant over.
I will now read the article via the link provided and maybe I will ask the same question again.

BIG-_JOHN
29th October 2014, 09:49 PM
OK, the link provided the same content as what was in the original post. I thought it may have been a more extensive read.
My original question stands.

Sharky1
30th October 2014, 12:19 AM
My wife's Nissan is an 05 GU 3l turbo soon due for a 150,000 service. This vehicle blows black smoke but only at start up. No smoke is evident later or under load. Fuel consumption is within normal boundaries (about 10.5 litres/100 kms) and power once turbo kicks in is good.
I haven't read the article yet but does anyone know what may cause this.

Cheers, John

As I wrote in my post above mate, which was also covered a little in the original post, if your fuel isn't fully burning, the carbon emissions (in the form of smoke) will be evident. Given that diesel needs to be hot & pressurized to burn well, which it isn't at initial start up, it blows a cloud of smoke. Also, given that upon start up, all you're engine's lubricants will have dropped to the bottom of the sump, manufacturers often design injection systems to squirt a larger than normal amount of diesel into the engine at start up to help lubricate it until oil pressure builds up. This may or may not be the case with your car.

nissannewby
30th October 2014, 05:21 PM
OK, the link provided the same content as what was in the original post. I thought it may have been a more extensive read.
My original question stands.

Get your glow plugs checked or even replaced. They should be done periodically on the di zd30.

nissannewby
30th October 2014, 05:26 PM
I'll get sidetracked........

Fixed :). Should have read the link. Some of your info is a little misleading but I can see you are trying to offer advice which we cannot get enough of. Diesels are in fact more efficient than petrols in their operation. I am a diesel fitter. The link is also a guide and can be quite helpful for those trying to to simple diagnostics by themselves before getting the mechanics involved.

BIG-_JOHN
31st October 2014, 03:55 AM
Get your glow plugs checked or even replaced. They should be done periodically on the di zd30.

Thanks, I will have a look at this at next service.

Sharky1
7th November 2014, 01:49 AM
Fixed :). Should have read the link. Some of your info is a little misleading but I can see you are trying to offer advice which we cannot get enough of. Diesels are in fact more efficient than petrols in their operation. I am a diesel fitter. The link is also a guide and can be quite helpful for those trying to to simple diagnostics by themselves before getting the mechanics involved.

It depends on which way you look at it. We both agree that one of the reasons a diesel engine could smoke is because it isn't completely burning all the diesel, which is quite common especially under load. How is that efficient? A diesel will still happily run like this though whereas if a petrol has the same issue, it usually has other problems related & doesn't run so well. Also, the average N/A diesel 4x4 will get approx 700km/100L. The average N/A petrol car of the same engine capacity will get 800km/100L with the only difference being the weight of the car. That's where diesels become more efficient. Because of the torque they can make, they'll pull a lot of weight with minimum additional fuel usage. Add a turbo to this & you can magnify that by a lot as a turbo on a diesel will increase economy. I have no doubt that you're a lot more full-bottle on it than I am. The only reason I posted all that is that most of the posts following the 1st were from seemingly paranoid folk who are suddenly thinking their diesel has an issue because it smokes. How can anyone who doesn't understand the basic fundamentals of this, diagnose anything?

Roland the Wolf
13th July 2015, 09:41 PM
Great post NISSANNEWBY . Since 3 months, I have a TD42T 1999 Patrol done 240000km. I have white smoke for about 10 seconds at cold starts and very rough idle. Idles ok, with no more smoke after 10 seconds at cold start and runs great once operating temp is reached. Any ideas, would be appreciated.
Thank you NISSANNEWBY. 13/7/2015

Johnny R
14th August 2015, 02:33 PM
Oh yes... I put a fuel star canister on my old 4.2.==1km/litre improvement and slightly more power. It simply adds Tin( close to lead on the periodic table) to the fuel, which increases the octane rating of the fuel...Excellent for petrols>

same
9th September 2015, 02:26 PM
thanks for this information

vidya31
12th March 2019, 10:24 PM
A pretty useful information.

Dazz76
7th October 2023, 04:27 PM
Thanks Mate ,Great Information