[carrot_eater]

Has any of the existing owners of Thar noticed that at times you get the smell of exhaust fumes in the cabin even when the windows are rolled up and the rear flap of the canopy is closed ?

I have done some trail and error and my observation is that when the blower (fan) is turned off - that's when I get the smell of exhaust fumes - even rolling the windows down does not help - the smell is there and it immediately goes off when the fan/blower is turned on.

Any ideas - why would the exhaust fumes come in and why does it stop when the blower is turned on.

If I am seeing some random correlation to the exhaust fumes and fan on position - is there a better way to understand / diagnose how the fumes end up in the Cabin?

[vj_k2001]

Hi,

Please do the foloowing check....

Start your vehicle early morning 7am (prefrabbly-cold weather) and drive it at 60-70 kmph for 2 kms.After which drive it in the second gear at 1600-1800 rpm and let me know if there is stalling.

The exhaust fumes smell will be very strong and there might be stalling.If both symptoms occur there is a procedure to be followed and only if the fumes smell occur there is a another fix.Please dont use the blower while doing this....If both the above dont occur then this is something new..

Regards,

Vijay

[carrot_eater]

Originally Posted by vj_k2001

Hi,

Start your vehicle early morning 7am (prefrabbly-cold weather) and drive it at 60-70 kmph for 2 kms.After which drive it in the second gear at 1600-1800 rpm and let me know if there is stalling.

The exhaust fumes smell will be very strong and there might be stalling.If both symptoms occur there is a procedure to be followed and only if the fumes smell occur there is a another fix.Please dont use the blower while doing this....If both the above dont occur then this is something new..

Thanks VJ - In fact I am noticing this when I am dropping my son to School - so definitely - the case that you've mentioned - cold start at 7:00 am and driving at 60-70 kmph and when I slow down for traffic - the smell is very strong.

I will try the second case of driving in 2nd gear and the rpm mentioned and see if it stalls tomorrow.

Until then - it will be of great help if you can mention the "fix" procedures in both cases.

Thanks again

[vj_k2001]

If both symtoms occur it means your ECU data set is corrupt and its s simple fix of getting your dataset re-loaded at your dealer.This will definetly fix the issue.Please remember to run it at a constant speed in the 2nd gear and the rpm range I mentioned.

If its only the smell then please change your catalytic convertor...Ask the dealer to replace your vehicle convertor with another,test is for a few days and 99.99% the issue would be fixed.

If this is happening only when the blower is switched on then its a new problem and we would have to rule out issues one by one from rail pressure to quality of diesel (test equipment is available with your dealer)

Regards,

Vijay

[shankar.balan]

My two bits on this from long ago experience;
most of these traditional soft top jeep type vehicles tend to get diesel smoke and diesel smell in their cabins. it also used to happen quite a bit in the old soft top gypsy but that was a sweetish sort of unburnt gases smell.
it is something to do with the square and flat rear side of the vehicle and the fact that there is a sort of vaccuum created behind the vehicle as it moves fast. this vaccuum again fills up with air which unfortunately is laden with the smell of unburnt gases whether diesel or petrol as the case may be.
Ive noticed this for absolutely ages - especially in the bad old days when we only had those ancient and wheezy CJ Series of Mahindra Jeeps - CJ 500 etc. Also in the soft top MM540's etc. And definitely in my old Soft top Gypsy as well.

[carrot_eater]

Originally Posted by shankar.balan

My two bits on this from long ago
it is something to do with the square and flat rear side of the vehicle and the fact that there is a sort of vaccuum created behind the vehicle as it moves fast. this vaccuum again fills up with air which unfortunately is laden with the smell of unburnt gases whether diesel or petrol as the case may be.

I understand about the vacuum creation and I've read elsewhere on this forum that you should keep the windshield down to reduce the effect of the vacuum created- however the issue seems to be different with the Thar - I have in fact noticed this smell only recently - I mean in last 4 months of owning it - I've realized this issue only like last week or so and that too only in early mornings. Maybe its because its a little colder now than before.

[Sutripta]

^^^
Does the Thar have a Fresh/ Recirc mode? And if so, is the blower in Fresh mode?

Regards
Sutripta

[condor]

Originally Posted by shankar.balan

most of these traditional soft top jeep type vehicles tend to get diesel smoke and diesel smell in their cabins.
...
it is something to do with the square and flat rear side of the vehicle ..

But I notice this problem occasionally even in my hard-top Sumo. Especially noticed after I come back (I drive, park the Sumo, and when I come back (not hours, but even upto half an hour or so).

[shankar.balan]

sorry bud - in my experience this was not selective - more like a permanent problem and as a youngster I used to get headaches if I sat for too long in the rear benches of the CJ. So we used to make frequent stops for fresh air and a bit of a walkabout.
could there be some sort of leak from the manifold or from somewhere else? that used to be another problem with some or other weak metal or rubber hoses causing carbon monoxide leakage into the cabin.
Frankly this is what I can think of - better to go to a proper Jeep mech/ expert really.

Originally Posted by carrot_eater

I understand about the vacuum creation and I've read elsewhere on this forum that you should keep the windshield down to reduce the effect of the vacuum created- however the issue seems to be different with the Thar - I have in fact noticed this smell only recently - I mean in last 4 months of owning it - I've realized this issue only like last week or so and that too only in early mornings. Maybe its because its a little colder now than before.

something perhaps to do with the manifold tubing or hoses?
could even be a leakage from the engine bay and/ or under the vehicle.
your Sumo is a little long in the tooth isnt it? might be worth checking (that old fashioned soap bubble test might be the easiest to do but by a mech of course).

Originally Posted by condor

But I notice this problem occasionally even in my hard-top Sumo. Especially noticed after I come back (I drive, park the Sumo, and when I come back (not hours, but even upto half an hour or so).

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[carrot_eater]

Originally Posted by vj_k2001

Start your vehicle early morning 7am (prefrabbly-cold weather) and drive it at 60-70 kmph for 2 kms.After which drive it in the second gear at 1600-1800 rpm and let me know if there is stalling.

The exhaust fumes smell will be very strong and there might be stalling.If both symptoms occur there is a procedure to be followed and only if the fumes smell occur there is a another fix.Please dont use the blower while doing this....If both the above dont occur then this is something new..

Well I tried the exact thing - drove for 60-70 Kmph for 2 kms and then in second gear at 1600-2000 rpm. No stalling and strangely no smell at all.

I mean even without the blower on - there was no smell at all this morning and I drove for over 30 kms. I tried various things - driving at low gear / high rpm . Drove at higher speed and then 2nd gear - rpm levels from 1600-2000 and even at 2500.

No smell - well this one looks like tough to reproduce and hence tougher to fix.

The only thing that has changed is I had got a tankful of diesel last night and perhaps it wasn't that cold this morning.

Does that impact?

For now I will wait until I encounter this issue again and that time hopefully it will be reproducible as well.

[Rajith]

all most all thar crde is having this issue and dealer manages now by stating that this is the smell of the hood !!.

I heard that M&M is going to replace the exhaust system for all THARs facing this issue soon with a down ward bend out let in rear as scorps..

[SPIKE ARRESTOR]

Rajith, even with the downward bend the smell will come.

Carroteater, please get in touch with Vijay- he knows the M&M dealer where his vehicle was troubleshooted ( I forgot the dealers name). The SA there knows the problem and its solution.

The cardinal rule while troubleshooting is to fix the cause and not the symptom. Cause is something else. That's all I can say now.

Spike

[Rajith]

Originally Posted by SPIKE ARRESTOR

Rajith, even with the downward bend the smell will come.

Carroteater, please get in touch with Vijay- he knows the M&M dealer where his vehicle was troubleshooted ( I forgot the dealers name). The SA there knows the problem and its solution.

The cardinal rule while troubleshooting is to fix the cause and not the symptom. Cause is something else. That's all I can say now.

Spike

spike i got an info from a ASC that the new exhaust kit has allready arrived with some tech changes to stop this issue with a down ward bend out let in limited nos and they have replaced for couple of THARs. They are expecting bulk supply soon.

[SPIKE ARRESTOR]

^^ That's great, hope & pray that it solves the issue then. Since you have been told by the ASC, I take it with a BIG pinch of salt.

Spike

PS- I still reiterate, this will not solve the problem completely. Over and out.

[DHABHAR.BEHRAM]

Originally Posted by SPIKE ARRESTOR

PS- I still reiterate, this will not solve the problem completely. Over and out.

Dear Pratheesh - reference your comment above, you have said it 100% correct! .

Dear Carrot Eater - the root cause needs to be identified and eliminated. For doing that, the first thing is that people "who matter", (not necessarily people who "understand"), need to agree that there is an "issue", for which there is a "root cause". If at all this is achieved, then something great is achieved. Then comes the question of doing the "correct thing" or "something", also "which agency" should do it. If it is only "something" which is done by "some agency", even if parts come to the dealership from God, vehicle "issues" cannot get resolved. Then, the whole cycle starts all over again. By the time things come to a head because you guys make a lot of noise about it, people "who matter" have usually got promoted or transferred so it does not make any difference to them at all. And as a customer who has paid money to buy the product, are you satisfied with what's done? Charts and fancy presentations are flaunted by people "who matter" to the "biggest people who matter", to prove that "AAL IZZ WELL".

MAY GOD HELP CUSTOMERS!

Dear Vijay - thanks for guiding Carrot Eater properly. I really appreciate.

Best regards,

Behram Dhabhar