Team-BHP (https://www.team-bhp.com/forum/)

-   Technical Stuff (https://www.team-bhp.com/forum/technical-stuff/)

-   -   Black smoke from diesel engines (https://www.team-bhp.com/forum/technical-stuff/39647-black-smoke-diesel-engines-8.html)

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.

F. E is just 8kmpl which is worrying him the most.

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?

Wow, some amazing explanations and reasoning on this thread. One of the most amusing threads on TBHP clap: for sure!!

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?

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.
:D

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

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.
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.

Apart from color, the smell also can also give an idea about whether it is coolant(head gasket) or oil(rings).

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.

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! :)