What does unburned diesel smoke smell like ?

[Tony Russell]

A wierd topic for a post, I know.

Trying to figure out what my latest source of smoke is - I think it's not the same as the one which was cured here:
http://www.mbclub.co.uk/forums/859727-post37.html

I think the smoke smells a bit like Vaseline, and is not as heavy as oily smoke.
I don't seem to be loosing oil.
I know that I had one injector not working efficiently at low revs two months back, maybe it's deteriorated. It is a little rough.
I only get it after idling and city driving. It can be cleared with a good rev.
There's not a loss of power that I can tell.
The oil separator is clean as a whistle. and there's nothing much in the EGR.
The fuel filter is only two months old.
The oil is new and the engine was flushed three weeks ago.
The dipstick is clean and there's no muck on the filler cap.
I don't have a furry dice.

Oh, it's an 02 Vaneo (A Class) 1.8 CDI.

This car is driving me nuts BTW.

Thanks,
Tony

 

[BlackC55]

I would be looking at that injector for the cause.

 

[chrisbrad66]

un burnt diesel has a grey/white/blue colour and a distinctive sickly smell, can't really compare it to vaseline as i dont know what that smells like,

 

[lynall]

Unburnt diesel will be black, usually caused by overfueling or lack of air ie blocked air filter etc.



Lynall

 

[pos.k]

un burnt diesel has a grey/white/blue colour and a distinctive sickly smell, can't really compare it to vaseline as i dont know what that smells like,

"Haven't you ever smothered yourself all over with Vaseline?"

 

[camerafodder]

Unburnt diesel appears white. Poorly burnt diesel appears black

 

[yachtman]

I would discribe un burnt /poorly burnt diesel as a phenolic smell, slightly similar to hot tar, with a slightly "sooty" aftertaste. usually white or pale blue colour, not as blue as burnt oil though.

 

[Tony Russell]

See, now I'm confused, 'cos I know you all know what you're talking about, however:

"un burnt diesel has a grey/white/blue colour and a distinctive sickly smell,"

"Unburnt diesel will be black, "

"Unburnt diesel appears white. Poorly burnt diesel appears black "

"I would discribe un burnt /poorly burnt diesel .... white or pale blue colour, not as blue as burnt oil though."



So it's blue, black, white and grey ?

Did an "Italian" up the M8 this morning. Noticed a puff agin though when I came off at the Kingston Bridge, so no improvement there.

First I'll change the air filter (if I can figure out how to get at it), and clean the inlet manifold. I'll stick in some neat Forte too to see if it helps the injector (I read somewhere that we get a more waxy diesel in winter - who knows).

Then I think I'm going to have to take a trip back to Mr. O'Neill again.
He did mention injector 3 early on, but said it was £200 for the bit, plus about a days labour to change it. So we're looking at <~ £1k to maybe fix a car that I hate more than I can express in a nice forum like this.

In saying that, if it worked perfectly, I'd have nothing to spend my leisure time on.

 

[chrisbrad66]

you only get black smoke when your air filter is blocked or some other restriction on the induction side,causing a rich mixture, i.e. too much fuel and not enough air, bluey white smoke is unburnt or poorly burnt fuel. However a small puff of smoke every now and then when you accelerate could just be the exhaust clearing itself out, all diesel engines will do this now and again

 

[whitenemesis]

"Smoke is the collection of airborne solid and liquid particulates and gases[1] emitted when a material undergoes combustion or pyrolysis, together with the quantity of air that is entrained or otherwise mixed into the mass"

"Mist is a phenomenon of small droplets suspended in air"

(Wikipedia)

Unburnt diesel would be mist, not smoke?

 

[yachtman]

See, now I'm confused, 'cos I know you all know what you're talking about, however:

"un burnt diesel has a grey/white/blue colour and a distinctive sickly smell,"

"Unburnt diesel will be black, "

"Unburnt diesel appears white. Poorly burnt diesel appears black "

"I would discribe un burnt /poorly burnt diesel .... white or pale blue colour, not as blue as burnt oil though."



So it's blue, black, white and grey ?

Did an "Italian" up the M8 this morning. Noticed a puff agin though when I came off at the Kingston Bridge, so no improvement there.

First I'll change the air filter (if I can figure out how to get at it), and clean the inlet manifold. I'll stick in some neat Forte too to see if it helps the injector (I read somewhere that we get a more waxy diesel in winter - who knows).

Then I think I'm going to have to take a trip back to Mr. O'Neill again.
He did mention injector 3 early on, but said it was £200 for the bit, plus about a days labour to change it. So we're looking at <~ £1k to maybe fix a car that I hate more than I can express in a nice forum like this.

In saying that, if it worked perfectly, I'd have nothing to spend my leisure time on.

Question is the puff of smoke seen while slowing down & no throttle, or while on power?

 

[Tony Russell]

Not so much a puff, more a mass when moving from idle to slight accelleration.
Fast(ish) driving doesn't appear to produce anything - thereby supporting the notion that the injector is not working at low revs. Sort of.

I bought an air filter this afternoon, but haven't fitted it yet.

I bought a bottle of Forte though and added it to two gallons of fuel and, after 1 hr / 30 miles, it appears to be better (motorway and then a couple of miles of town).

Leaving it idling, then giving it a rev, there's still a good puff though.
When I say puff, I mean a cloud. A fog - more than a mist.

I'll try it again in the morning and drop another video, then change the air filter (if I can figure out how) and see what happens.
I think that changing the air filter involves removing the fuel filter and the oil separator before the inlet manifold cover can be removed.
Unfortunately Bert Rowe's manual doesn't cover the diesel so I'll take pics for him to stick on his website. Hopefully help the next poor b'stard that is stuck with one of these.

 

[Satch]

United Diesel UK &ndash; Diesel Engine Smoke Explained

 

[Tony Russell]

Thanks for that. Top article.

BTW - I don't know who Mr Forte is, but he sure does make exceedingly good engine juice.

After adding the stuff as I said above it is now running cleanly and more smoothly too.

Lets see how long it lasts this time - though I'm now fairly resigned to the fact I'll likely have to replace the injector long term.


thanks,
Tony

 

[sspeed]

Hi,
I dont know if this helps but my C270 CDI spends most of its time pootling to and from work..
The odd time I boot it (When joining a motorway) you have to see the smoke to believe it..
But this soon stops once its cleared its lungs..
I would describe it as Grey / Black (with a aquamarine hue)... Only joking about the aquamarine Lol