Go Back   Team-BHP > Under the Hood > Technical Stuff


Reply
 
Thread Tools Search this Thread
Old 12th September 2014, 14:11   #106
BHPian
 
Join Date: Aug 2012
Location: Bangalore
Posts: 131
Thanked: 88 Times
Default re: Black smoke from diesel engines

so after all this, i have a question
In Bangalore, when i rev the engine of my Storme, the ubiquitous black smoke appears. However, when i do the same thing in Chennai it does not. Why ? All driving conditions remain the same. High torque, same gear, same speed

Is it that Bangalore has better O2 content that Chennai ?
subraiyr is offline   Reply With Quote
Old 12th September 2014, 14:30   #107
Distinguished - BHPian
 
a4anurag's Avatar
 
Join Date: Oct 2011
Location: Hyderabad
Posts: 8,874
Thanked: 11,759 Times
Default

Quote:
Originally Posted by subraiyr View Post
so after all this, i have a question
In Bangalore, when i rev the engine of my Storme, the ubiquitous black smoke appears. However, when i do the same thing in Chennai it does not. Why ? All driving conditions remain the same. High torque, same gear, same speed

Is it that Bangalore has better O2 content that Chennai ?
Air and fuel quality could be the difference.

Anurag.
a4anurag is offline   Reply With Quote
Old 12th September 2014, 14:50   #108
BHPian
 
Join Date: Sep 2013
Location: Hyderabad
Posts: 956
Thanked: 428 Times
Default re: Black smoke from diesel engines

Quote:
Originally Posted by SS-Traveller View Post
Look for oil in coolant, or water contamination of engine oil. Head gasket likely to need attention. How is the FE?
F. E is just 8kmpl which is worrying him the most.
JoseVijay is offline   Reply With Quote
Old 12th September 2014, 15:23   #109
BHPian
 
Join Date: Oct 2005
Location: Chennai
Posts: 331
Thanked: 414 Times
Default re: Black smoke from diesel engines

Quote:
Originally Posted by subraiyr View Post
so after all this, i have a question
In Bangalore, when i rev the engine of my Storme, the ubiquitous black smoke appears. However, when i do the same thing in Chennai it does not. Why ? All driving conditions remain the same. High torque, same gear, same speed

Is it that Bangalore has better O2 content that Chennai ?
Air in B'luru will be thinner(lower atmospheric pressure) since the altitude is there is nearly 900M or 3000 ft against the almost zero metre or feet in Chennai. Therefore the same volume of air there should be more O2 in Chennai. But the Engine management system is supposed to take care of the quantity of fuel injected accordingly based on the various inputs from the sensors. Probably the smoke is only transient. Does the smoke keep coming when you hold a higher rpm or vanish after a short moment?
arulpeem is offline   Reply With Quote
Old 12th September 2014, 16:12   #110
BHPian
 
Kaumad's Avatar
 
Join Date: Jul 2010
Location: Chennai
Posts: 128
Thanked: 120 Times
Default re: Black smoke from diesel engines

Wow, some amazing explanations and reasoning on this thread. One of the most amusing threads on TBHP for sure!!
Kaumad is offline   Reply With Quote
Old 12th September 2014, 16:55   #111
Senior - BHPian
 
akshay4587's Avatar
 
Join Date: Mar 2005
Location: Chandigarh/Mohali/Ambala Cantt
Posts: 3,758
Thanked: 1,520 Times
Default re: Black smoke from diesel engines

This year in June;At Chitkul 11400Ft above sea level.
Two Thar's both 6 months old with under 10K kms on odo started spewing out bluish white smoke at cold start up.There was another Brand new Bolero DI turbo doing the same; was this due to excess fuel being burnt and lack of air?
akshay4587 is offline   Reply With Quote
Old 12th September 2014, 17:03   #112
Distinguished - BHPian
 
SS-Traveller's Avatar
 
Join Date: Jan 2009
Location: New Delhi
Posts: 6,526
Thanked: 10,266 Times
Default re: Black smoke from diesel engines

Quote:
Originally Posted by JoseVijay View Post
F. E is just 8kmpl which is worrying him the most.
Ask your friend to recalibrate his fuel pump and injectors on a diesel test bench. If that does not solve the problem, the cylinder head has to be removed and gasket checked for leakage. White smoke is usually due to either overfuelling or coolant in combustion chamber.
Quote:
Originally Posted by Kaumad View Post
Wow, some amazing explanations and reasoning on this thread. One of the most amusing threads on TBHP for sure!!
SS-Traveller is offline   (1) Thanks Reply With Quote
Old 12th September 2014, 18:56   #113
Senior - BHPian
 
Join Date: Sep 2007
Location: New Delhi
Posts: 3,076
Thanked: 249 Times
Default re: Black smoke from diesel engines

Quote:
Originally Posted by SS-Traveller View Post
....White smoke is usually due to either overfuelling ....
Would you please explain what this term means?
Do you mean excess fuel being injected into the combustion chambers?
anupmathur is offline   Reply With Quote
Old 12th September 2014, 19:20   #114
Distinguished - BHPian
 
SS-Traveller's Avatar
 
Join Date: Jan 2009
Location: New Delhi
Posts: 6,526
Thanked: 10,266 Times
Default re: Black smoke from diesel engines

Quote:
Originally Posted by anupmathur View Post
Would you please explain what this term means?
Do you mean excess fuel being injected into the combustion chambers?
Yes. See http://www.kiwicylinderheads.com/Tip...Explained.aspx
Quote:
The Answer is in the Smoke

We can generally understand what is wrong with a diesel engine by the colour of smoke emitted from the exhaust. There are three basic colours - black, white and blue.

Black Smoke

This is due to a air to fuel ratio imbalance, either the fuel system is delivering too much fuel into the engine or there is not enough clean air (oxygen ) a few things to look for :
  • Faulty injectors (injectors need attention at about 100.000 to 120 000 miles)
  • Faulty injector pump
  • Dirty air cleaner
  • Turbocharger or intercooler faulty
  • Problems within cylinder head, valves clogged up due to faulty EGR (exhaust gas recycling unit)

White Smoke

Normally means that the fuel injected into the cylinder is not burning correctly. The smoke will burn your eyes.
  • Engine/pump timing out
  • Fuel starvation to the pump causing the pumps timing not to operate correctly
  • Low engine compression
  • Water/petrol in the fuel

Blue Smoke
  • The engine is burning engine oil
  • Worn cylinders or piston rings
  • Faulty valves or valve stem seals
  • Engine over full with engine oil
  • Faulty injector pump/lift pump allowing engine oil to be mixed with the diesel

Last edited by SS-Traveller : 12th September 2014 at 19:23.
SS-Traveller is offline   (2) Thanks Reply With Quote
Old 12th September 2014, 20:40   #115
Senior - BHPian
 
Join Date: Sep 2007
Location: New Delhi
Posts: 3,076
Thanked: 249 Times
Default re: Black smoke from diesel engines

Quote:
Originally Posted by anupmathur View Post
....
Do you mean excess fuel being injected into the combustion chambers?
Quote:
Originally Posted by SS-Traveller View Post
Yes....
Which is why I asked. I think you are mis-reading the white smoke part.
It does not say that excess fuel is being injected; what it says is that the injected fuel (which will be less than optimal due to fuel starvation) is not getting burnt effectively.
Quote:
White Smoke Normally means that the fuel injected into the cylinder is not burning correctly. The smoke will burn your eyes.
  • Engine/pump timing out
  • Fuel starvation to the pump causing the pumps timing not to operate correctly
  • Low engine compression
  • Water/petrol in the fuel
Excess fuel injected into a healthy cylinder will always give black smoke, never white!
anupmathur is offline   Reply With Quote
Old 12th September 2014, 20:50   #116
Distinguished - BHPian
 
SS-Traveller's Avatar
 
Join Date: Jan 2009
Location: New Delhi
Posts: 6,526
Thanked: 10,266 Times
Default re: Black smoke from diesel engines

Quote:
Originally Posted by anupmathur View Post
Which is why I asked. I think you are mis-reading the white smoke part.
It does not say that excess fuel is being injected; what it says is that the injected fuel (which will be less than optimal due to fuel starvation) is not getting burnt effectively.[/list]Excess fuel injected into a healthy cylinder will always give black smoke, never white!
Maybe LR Tdi engines behave differently.
http://www.landyzone.co.uk/lz/f46/wh...ng-191256.html

Sometimes seeing the real thing helps - can't smell the smoke online.
SS-Traveller is offline   Reply With Quote
Old 12th September 2014, 20:53   #117
Senior - BHPian
 
Join Date: Dec 2006
Location: NH209
Posts: 1,607
Thanked: 697 Times
Default re: Black smoke from diesel engines

Quote:
Originally Posted by anupmathur View Post
[/list]Excess fuel injected into a healthy cylinder will always give black smoke, never white!
Apart from color, the smell also can also give an idea about whether it is coolant(head gasket) or oil(rings).
ramzsys is offline   (1) Thanks Reply With Quote
Old 12th September 2014, 21:21   #118
Senior - BHPian
 
Join Date: Sep 2007
Location: New Delhi
Posts: 3,076
Thanked: 249 Times
Default re: Black smoke from diesel engines

Quote:
Originally Posted by SS-Traveller View Post
Maybe LR Tdi engines behave differently.
...
Sorry sir, we're talking Pajero here. Mitsubishi, not LR!
And even LR engines abide by the laws of Physics AT ALL TIMES.
Do read the linked article again. Nowhere does it say that excess fuel can give white smoke.
At hugely negative ambient temperatures, yes, maybe for a very brief duration; else no. But then the physical and chemical properties of fuels change radically at hugely negative ambient temperatures.
anupmathur is offline   Reply With Quote
Old 13th September 2014, 03:53   #119
Distinguished - BHPian
 
a4anurag's Avatar
 
Join Date: Oct 2011
Location: Hyderabad
Posts: 8,874
Thanked: 11,759 Times
Default

Quote:
Originally Posted by anupmathur View Post
Sorry sir, we're talking Pajero here. Mitsubishi, not LR!
And even LR engines abide by the laws of Physics AT ALL TIMES.
Do read the linked article again. Nowhere does it say that excess fuel can give white smoke.
At hugely negative ambient temperatures, yes, maybe for a very brief duration; else no. But then the physical and chemical properties of fuels change radically at hugely negative ambient temperatures.
Blue smoke is mostly engine oil consumption and not excessive fuel injection.

Excessive fuel would be black colour.

Anurag.
a4anurag is offline   Reply With Quote
Old 13th September 2014, 10:17   #120
Distinguished - BHPian
 
SS-Traveller's Avatar
 
Join Date: Jan 2009
Location: New Delhi
Posts: 6,526
Thanked: 10,266 Times
Default re: Black smoke from diesel engines

Quote:
Originally Posted by anupmathur View Post
Sorry sir, we're talking Pajero here.
Quote:
Originally Posted by JoseVijay View Post
My friend recently bought a pre-owned Bolero GLX (2003 model).
Sir, if you read others' posts as closely as you try to analyse the exact meaning of every single word in mine, you'll realize that we are discussing a Di diesel on a Mahindra Bolero here with an inline injection pump, without ECUs, common rail and other miscellaneous electronics, and not a Mitsubishi Pajero.

I don't Google to find explanations at the first instance, and then copy-paste them on this forum - my teacher is experience. The link (http://www.kiwicylinderheads.com/Tip...Explained.aspx) that I posted addresses the whole essence of this thread, i.e. the general reasons for different types of smoke from a diesel engine tailpipe. If I've used the word *overfuelling*, I am not quoting a Google resource, but simply saying that there is fuel being injected that cannot be burnt completely.

I have advised the member whose friend is facing problems with his Bolero, to have the injectors and pump recalibrated on a diesel test bench, and that is because there is likely to be an issue with the diesel fuel injection. Now call it overfuelling, misfuelling, poor spray pattern or whatever else, but one of the reasons for white smoke is incomplete burning of fuel, also showing up as poor FE. Black smoke is also possible, but it is not sacrosanct that **excess fuel = black smoke only**. Black smoke is frequently seen under heavy acceleration, and is also seen in completely healthy engines. Calibrating the pump and injectors will show up faults as well as (hopefully) correct the FE (one would certainly expect pump and injector issues in a 11-year-old vehicle without known service history).

If calibrating pump & injectors does not solve the smoke problem, the next step would be to check the head gasket for coolant leaks, Even without external evidence of such a leak (oil in coolant or colour change of engine oil), minor leaks across the gasket separating water jacket from cylinder bore can occur - which can only be verified by removing the head and checking. At the same time the pistons and rings can be visually inspected too (loss of compression also causes white smoke, only because the diesel is again being burnt improperly/inadequately - and this will continue to manifest itself through poor FE).

Hope that explains things a little better.

Here's also hoping our fellow member below remains suitably entertained in the coming times. Would also request his contribution to solving individual members' problems sometimes!
Quote:
Originally Posted by Kaumad View Post
Wow, some amazing explanations and reasoning on this thread. One of the most amusing threads on TBHP for sure!!

Last edited by SS-Traveller : 13th September 2014 at 10:21.
SS-Traveller is offline   (1) Thanks Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Do Diesel engines generate more Torque than Petrol engines? ex670c Technical Stuff 224 25th November 2013 12:20
Difference between old engines and new engines (petrol and diesel) srijit Technical Stuff 32 26th January 2011 10:20
black smoke from exhaust 2fast4u Technical Stuff 32 10th August 2010 13:48
(Royal Enfield) Thick black smoke when revved hard. ron_9191 Motorbikes 43 13th October 2009 13:50
Verna crdi: black smoke from exhaust live2drive Technical Stuff 32 26th November 2008 11:43


All times are GMT +5.5. The time now is 14:58.

Copyright 2000 - 2017, Team-BHP.com
Proudly powered by E2E Networks