Car exhaust smells like burnt paper, whats gone bad?

gigy · 13th September 2009, 15:54

Hi all, The other day i had to spend a long time in car parking testing the carputer with engine on, what i noticed was that the exhaust air around smelling like burnt paper, there is no water in the tail pipie also nowadays, have i damaged the silencer or catlytic converter? is there any issue in letting it be like that ? could there be any other other cause?

adityamunshi · 13th September 2009, 16:46

Which car ? How many kms done ?

gigy · 13th September 2009, 17:47

Its a baleno done 93k kms.

SS-Traveller · 13th September 2009, 17:55

A burnt-paper kind of pungent smell from the exhaust is likely due to your engine oil being burnt in the combustion chamber. Oil control rings may have gone, and a ring change may be due.

Open up the spark plugs (when the engine is cooled down) and check if they are running greyish/blackish, rather than the whitish normal colour.

Lift up the dipstick or open the oil cap while the engine idles - a visible smoke coming out from either is a good sign that your engine is asking for new rings.

gigy · 13th September 2009, 18:35

you have scared me. a month back when i openned the plugs they were black. will check the plugs and oil. i am using mobil1 from the last 40k kms.

SS-Traveller · 13th September 2009, 19:07

Try comparing your spark plugs to this chart: Verrill: Plug Color Chart.

vigsom · 13th September 2009, 21:03

You could also run your fingeron the inside of the tail pipe(Be CAREFUL Not to hurt yourself as the tail pipes could be corroded) - when the engine is off and cold.

"Kajal" or thick black deposit is another sureshot tell tale sign of worn out rings

SS-Traveller · 13th September 2009, 21:25

Quote:

Originally Posted by vigsom

"Kajal" or thick black deposit is another sureshot tell tale sign of worn out rings

Not necessarily. If the car has been running on a rich mixture (such as with the choke pulled out on pre-MPFi cars, or a dripping injector in an MPFi), such carbon deposits are also possible in the tailpipe.

gigy · 14th September 2009, 20:13

I have checked the spark plugs and don't find any oil marks. pictures below. there was no visible smoke or fumes from engine oil while running. the exhaust also has no soot deposits. i am also having backfire problem due lpg which is not solved till now.

SS-Traveller · 14th September 2009, 20:20

Plugs seem normal. Is the burnt paper smell still there? Did you leave the car on idle for a prolonged period? Has your FE dropped lately (indicating the mixture is running rich)?

gigy · 14th September 2009, 20:25

Yes car was idling with ac for more than a hour when i was configuring the carputer. i dont check fuel efficiency with petrol but with lpg is seems consistent.
Can the backfire cause catcon and silencer damage?

SS-Traveller · 14th September 2009, 20:33

Quote:

Originally Posted by gigy

...with lpg is seems consistent.
Can the backfire cause catcon and silencer damage?

OH! That explains it - you're running on LPG. Idling on LPG does give a funny smell at times. All this time I was thinking you're running on petrol. And you never mentioned backfiring earlier. Anyway, all's well - have fun.

Catcon should be just fine, but there is really no easy way you can check.

Where's the thread on your carputer?

gigy · 14th September 2009, 20:45

That particular day it was idling on petrol only as lpg tank is empty. i hope its only due to the lpg exhaust. let me run for some more time and see if there is any deterioration in car performance. Thank you very much for the help.
regarding carputer its here
http://www.team-bhp.com/forum/sound-...ter-setup.html

13th September 2009, 15:54	#1
gigy Senior - BHPian Join Date: Jul 2006 Location: mumbai Posts: 1,321 Thanked: 47 Times	Car exhaust smells like burnt paper, whats gone bad? Hi all, The other day i had to spend a long time in car parking testing the carputer with engine on, what i noticed was that the exhaust air around smelling like burnt paper, there is no water in the tail pipie also nowadays, have i damaged the silencer or catlytic converter? is there any issue in letting it be like that ? could there be any other other cause?
	() Thanks

13th September 2009, 16:46	#2
adityamunshi BHPian Join Date: May 2007 Location: Baroda Posts: 771 Thanked: 6 Times	Which car ? How many kms done ?
	() Thanks

13th September 2009, 17:47	#3
gigy Senior - BHPian Join Date: Jul 2006 Location: mumbai Posts: 1,321 Thanked: 47 Times	Its a baleno done 93k kms.
	() Thanks

13th September 2009, 17:55	#4
SS-Traveller Distinguished - BHPian Join Date: Jan 2009 Location: New Delhi Posts: 8,276 Thanked: 28,712 Times View My Garage	A burnt-paper kind of pungent smell from the exhaust is likely due to your engine oil being burnt in the combustion chamber. Oil control rings may have gone, and a ring change may be due. Open up the spark plugs (when the engine is cooled down) and check if they are running greyish/blackish, rather than the whitish normal colour. Lift up the dipstick or open the oil cap while the engine idles - a visible smoke coming out from either is a good sign that your engine is asking for new rings.
	() Thanks

13th September 2009, 18:35	#5
gigy Senior - BHPian Join Date: Jul 2006 Location: mumbai Posts: 1,321 Thanked: 47 Times	you have scared me. a month back when i openned the plugs they were black. will check the plugs and oil. i am using mobil1 from the last 40k kms. Last edited by gigy : 13th September 2009 at 18:38.
	() Thanks

13th September 2009, 19:07	#6
SS-Traveller Distinguished - BHPian Join Date: Jan 2009 Location: New Delhi Posts: 8,276 Thanked: 28,712 Times View My Garage	Try comparing your spark plugs to this chart: Verrill: Plug Color Chart.
	() Thanks

13th September 2009, 21:03	#7
vigsom Distinguished - BHPian Join Date: Feb 2006 Location: NSEW Posts: 4,009 Thanked: 29,823 Times	You could also run your fingeron the inside of the tail pipe(Be CAREFUL Not to hurt yourself as the tail pipes could be corroded) - when the engine is off and cold. "Kajal" or thick black deposit is another sureshot tell tale sign of worn out rings
	() Thanks

14th September 2009, 20:13	#9
gigy Senior - BHPian Join Date: Jul 2006 Location: mumbai Posts: 1,321 Thanked: 47 Times	I have checked the spark plugs and don't find any oil marks. pictures below. there was no visible smoke or fumes from engine oil while running. the exhaust also has no soot deposits. i am also having backfire problem due lpg which is not solved till now. Attached Thumbnails Last edited by gigy : 14th September 2009 at 20:15.
	() Thanks

14th September 2009, 20:20	#10
SS-Traveller Distinguished - BHPian Join Date: Jan 2009 Location: New Delhi Posts: 8,276 Thanked: 28,712 Times View My Garage	Plugs seem normal. Is the burnt paper smell still there? Did you leave the car on idle for a prolonged period? Has your FE dropped lately (indicating the mixture is running rich)?
	() Thanks

14th September 2009, 20:25	#11
gigy Senior - BHPian Join Date: Jul 2006 Location: mumbai Posts: 1,321 Thanked: 47 Times	Yes car was idling with ac for more than a hour when i was configuring the carputer. i dont check fuel efficiency with petrol but with lpg is seems consistent. Can the backfire cause catcon and silencer damage? Last edited by gigy : 14th September 2009 at 20:27.
	() Thanks

14th September 2009, 20:45	#13
gigy Senior - BHPian Join Date: Jul 2006 Location: mumbai Posts: 1,321 Thanked: 47 Times	That particular day it was idling on petrol only as lpg tank is empty. i hope its only due to the lpg exhaust. let me run for some more time and see if there is any deterioration in car performance. Thank you very much for the help. regarding carputer its here http://www.team-bhp.com/forum/sound-...ter-setup.html
	() Thanks