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Discussion Starter #1
I test drove a GC Overland yesterday and during my round the block drive a definite strong burning odor entered the cabin, and lingered for the remaining drive. The salesman indicated it was "new car burn off", I suspected it was the DEF filter burning particulates. My question to the board is, Does this smell enter the cabin every time the DEF regenerates? If so, I may have to pass on the GC.
 

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A few diesel newbie issues here...
1) DEF is Diesel Exhaust Fluid which is an additive added to the fuel and burned in combustion. It is basically Urea.
2) A regen is done by the Diesel Particulate Filter DPF. This is only done when needed and I highly doubt that during a test drive that a regen would trigger.

Diesel vehicles are going to have smells. Shoot just filling them up, a slight drop or two on your loafers brought into the Jeep will linger longer than you might think.
Changing oil too will have different smells to it that a gas vehicle.

I am not sure what you smelled on your test drive. Could be something burning off, could be something wrong also. I don't know. Most Clean Diesel vehicles have little smell out the tailpipe. So much less than a big rig does.

If you are bothered by smells, then a diesel MAY NOT be the vehicle for you.

My .02 cents

P.S. I used to deliver fuels for a living, driven Class A and B rigs for over 40 years. So that just might mean my old sniffer is more tolerant than yours.
 

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1) DEF is Diesel Exhaust Fluid which is an additive added to the fuel and burned in combustion. It is basically Urea.


Actually, DEF is stored in a separate tank and is injected into the exhaust stream after combustion. From Wiki...

"Diesel engines can be run with a lean burn air-to-fuel ratio (overstoichiometric ratio), to ensure the full combustion of soot and to prevent the exhaust of unburnt fuel. The excess of oxygen necessarily leads to generation of nitrogen oxides (NO[SUB]x[/SUB]), which are harmful pollutants, from the nitrogen in the air. Selective catalytic reduction is used to reduce the amount of NO[SUB]x[/SUB] released into the atmosphere. Diesel exhaust fluid (from a separate DEF tank) is injected into the exhaust pipeline, the aqueous urea vaporizes and decomposes to form ammonia and carbon dioxide. Within the SCR catalyst, the NO[SUB]x[/SUB] are catalytically reduced by the ammonia (NH[SUB]3[/SUB]) into water (H[SUB]2[/SUB]O) and nitrogen (N[SUB]2[/SUB]), which are both harmless; and these are then released through the exhaust."
 

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I think I smelled the smell that has been addressed, over and over. If it is the same and I'm thinking it is, it was about mile 75 to 90 of my new Limited. I had two passengers and neither commented on it... One is a heavy smoker and I'm not sure she can smell anything, the other was my wife and I think if she did she was thinking it was me. I didn't mention it because I thought I would be ringing a bell I couldn't unring. Neither of them read this forum. At work I make rubber stamps with a laser engraver and it smelled kinda like that. I have since only put another 100 or so miles on the car and all I smell is new car and leather. But I am very happy with the vehicle so far and find hard to believe that with so many diesel cars on the road using DEF that this could be a major problem. I do understand that some people have a sensitive sense of smell and perhaps diesel is not the right thing for them. But I also think some people can smell what they smelling for even if it's not there.

But I think it was there.... But no regrets so far.

When the weather warms I intend on finding out where the DEF tank vents.
 

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I had that smell come into the cabin early on as well, I figured it was something of a "burn off" situation. I just made sure in the meantime that I set the air to recirculate the air instead of bringing in fresh air from the outside. I now have 1800 miles on my Jeep and can't remember the last time I had that smell. I can't imagine it has anything to due with DEF as DEF is initiated in the exhaust system which you shouldn't be able to smell in the cabin.
 

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We had an issue with this after 500 miles. Just a strong exhaust odor for a few minutes, I even thought there was a puff of smoke from under the hood. Nothing since then and we are at 1200 miles. If anything, DEF would prevent any odors in the tailpipe. I had the vehicle running while I connected the trailer lights, squatted down right by the tailpipe and never smelled anything like I would have expected from an oil burner. In fact the tailpipe aroma was eerily neutral and almost non-detectable. Describable like fine wine: the aroma had hints of chocolate with a fruity finish.
 

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I think that the DEF tank is positioned so that cabin air is circulated around it to facilitate thawing is the winter and cooling in the summer. I also believe that under certain circumstances that the "smell" could return. I have had several new cars and remember no such thing as burn off. I have had burn off from installed exhaust components and at times spilled oil on hot parts. The burn off happened as soon as the car was started not 50 miles later.. I am curious to know where and how the DEF tank is vented and I will figure this out as soon as the weather decides to get above 30. The answer to the problem may be as simple as making sure the DEF is not past expiration or not tightening the fill cap all the way. And while the DEF tank is not heated the lines are. This could cause some back pressure. I do think it's DEF related.... But I'm hardly ever right and have nothing to back this opinion.
I had that smell come into the cabin early on as well, I figured it was something of a "burn off" situation. I just made sure in the meantime that I set the air to recirculate the air instead of bringing in fresh air from the outside. I now have 1800 miles on my Jeep and can't remember the last time I had that smell. I can't imagine it has anything to due with DEF as DEF is initiated in the exhaust system which you shouldn't be able to smell in the cabin.
 

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I think that the DEF tank is positioned so that cabin air is circulated around it to facilitate thawing is the winter and cooling in the summer. I also believe that under certain circumstances that the "smell" could return. I have had several new cars and remember no such thing as burn off. I have had burn off from installed exhaust components and at times spilled oil on hot parts. The burn off happened as soon as the car was started not 50 miles later.. I am curious to know where and how the DEF tank is vented and I will figure this out as soon as the weather decides to get above 30. The answer to the problem may be as simple as making sure the DEF is not past expiration or not tightening the fill cap all the way. And while the DEF tank is not heated the lines are. This could cause some back pressure. I do think it's DEF related.... But I'm hardly ever right and have nothing to back this opinion.
I'm not sure about your thoughts on the DEF tank and cabin air. It's clearly located outside the cabin just forward of the rear bumper below the spare wheel well. I can't claim to know this for a fact, but somehow I doubt there would be cabin air vents exiting under the vehicle exactly for the reason of introducing exhaust fumes into the cabin. DEF is also supposedly good to -12F so I don't think there is much practical reason to try to control the temperature of the fluid. The tank is heavy gauge steel, which you can see for yourself is you tap on it, so even if the DEF were to freeze, as long as it's not overfilled into the filler neck, its's not going to damage the tank. The odor from the DEF smells very clearly and strongly of ammonia. If you are smelling something that is not akin to ammonia, it's not the DEF.

Mine has done at least one DPF regen that I was aware of, and only because when I pulled in into the garage you could tell the exhaust was way hot and had a bit of a burning smell to it.

The other day when I was washing it I was noticing how the cowl vent is designed, just below the rear part of the hood. The way they designed, it, it's possible that there is a strong venturi effect there at the back edge of the hood and maybe that is why external odors are more easily picked up? Pure speculation, but made sense to me when I looked at the vent inlet a bit closer.
 

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Discussion Starter #9
I have been looking into a diesel SUV for a few months now and have read both the VW Touareg forums, which includes Audi and Porsche diesels, and the BMW forums. In both the Audi and BMW, there is a large filter that traps particulates before it gets into the exhaust system and before adblue is injected. This filter regenerates itself by burning off the particulates the system determines it is getting clogged. There has been mention on the VW and BMW forums about a slight burning smell that will last for a few seconds, but what I experienced seemed to be excessive in the GC. I was just wondering if this was common or if it was just some type of one off problem. I may test drive a couple of more at different dealers in the area to be sure.

I am not sure of the particulars of the Fiat diesel, but I would assume its exhaust system is similar to the VW and BMW systems. If you want to see how the VW system works, check out this youtube video, VW Touareg TDI and Audi Q7 Adblue emissions explained - YouTube
 

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Now I'm not so sure either.... as soon as the weather warms up I will look closer. But your observations sound logical.
I'm not sure about your thoughts on the DEF tank and cabin air. It's clearly located outside the cabin just forward of the rear bumper below the spare wheel well. I can't claim to know this for a fact, but somehow I doubt there would be cabin air vents exiting under the vehicle exactly for the reason of introducing exhaust fumes into the cabin. DEF is also supposedly good to -12F so I don't think there is much practical reason to try to control the temperature of the fluid. The tank is heavy gauge steel, which you can see for yourself is you tap on it, so even if the DEF were to freeze, as long as it's not overfilled into the filler neck, its's not going to damage the tank. The odor from the DEF smells very clearly and strongly of ammonia. If you are smelling something that is not akin to ammonia, it's not the DEF.

Mine has done at least one DPF regen that I was aware of, and only because when I pulled in into the garage you could tell the exhaust was way hot and had a bit of a burning smell to it.

The other day when I was washing it I was noticing how the cowl vent is designed, just below the rear part of the hood. The way they designed, it, it's possible that there is a strong venturi effect there at the back edge of the hood and maybe that is why external odors are more easily picked up? Pure speculation, but made sense to me when I looked at the vent inlet a bit closer.
 

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Either way you look at it, there does seem to a way for external smells to pick up in the cabin very quickly. Keeping the internal air circulating would help...
 

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I took mine back to the dealer about a funky smell and was told that there are some stickers on the exhaust burning off. I have around 4500 miles on my jeep and I still get the smell once in a while but it seems to get less and less.
 

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I was smelling something and it wasn't going away. I've got 2600 miles on mine now and although I'm used to the smell of diesel exhaust I thought I would ake it in so they could check it. I also had a rattle underneath that was driving me nuts. The found an exhaust leak and a bolt rolling around the heat shield. The bolt was unused and they have no idea where it came from. They are going to fix it on monday.

I took mine back to the dealer about a funky smell and was told that there are some stickers on the exhaust burning off. I have around 4500 miles on my jeep and I still get the smell once in a while but it seems to get less and less.
 

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I was told the same thing today, after I was told friday it had an exhaust leak.

I took mine back to the dealer about a funky smell and was told that there are some stickers on the exhaust burning off. I have around 4500 miles on my jeep and I still get the smell once in a while but it seems to get less and less.
 

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I have owned an emissions equipped Dodge Diesel truck since 2007. They have a DPF "Diesel Particulate Filter" Without getting to technical what it basically does is collect unburned soot from the exhaust system and when the system determines that it has collected enough soot it will allow extra fuel to be used to heat up the DPF causing it to burn off the soot in order to keep the NOX levels down. This process is called regeneration or "regen" When the vehicle is in regen mode it is normal to smell a burning smell. From my experience there are different types of regeneration. Some are short and last only a few minutes and some last up to 15 minutes. The longer Regen cycles typically happen when driving at highway speeds. It is necessary to keep the DPF from clogging up. This process is supposed to be unnoticeable to the drivers however it was such a problem with the Dodge trucks where the DPF was getting full and causing the trucks to go into limp mode or evan shut off that the aftermarket programmers have a feature in them to force regen and to be able to monitor when it occurs. It was very easy to tell with the aftermarket programmer / gauge setup as they allow the drivers to monitor the EGT's Exhaust gas temperatures. They would often climb up past 1400 degrees. Most of the problems were from drivers using fuel that was not Ultra low sulfur which is now all that is available at the pumps since 2010.
Long extended idling , Programming issues as well as not driving the vehicles for long enough periods for regeneration to complete "highway driving" are also some of the reasons for the past issues. I am hopping that the engineers have learned some things in the past seven years and that clogged DPF filters are a thing of the past but I guess only time will tell.
 

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Burning Smell

My Jeep Grand Cherokee Diesel has had this issue since new. I took it to the dealer at 300 miles , they couldn't find an issue. Finially at 1200 miles the MIL and DEF light came on. Took it to the dealer and they found the DEF Tank empty and the DEF Doser control leaking, they replaced it (was in shop for 2 weeks). That took care of the DEF leaking, but I still had a strong odor in the cabin/burning smell. At 2600 miles the MIL light came on agaiin, I took it to the dealer and they found the EGR Valve defective, they replaced it, (over a week in the shop). it seems much better now but I still have the smell at times. I have been told they are working on it but I don't think they have a solution. I have driven other Diesels, Mercedes ML Bluetech and VW Toureg, and though they may have some exterior diesel odors the smell doesn't enter the cabin with the windows closed. My neighbor has a VW no odor at all. My feeling is that exhaust system may have some leaks or the body/cabin may have some areas that let the exhaust fumes enter at times, i.e. backing up, exiting the Interstate or in heavy traffic.
 

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My Jeep Grand Cherokee Diesel has had this issue since new. I took it to the dealer at 300 miles , they couldn't find an issue. Finially at 1200 miles the MIL and DEF light came on. Took it to the dealer and they found the DEF Tank empty and the DEF Doser control leaking, they replaced it (was in shop for 2 weeks). That took care of the DEF leaking, but I still had a strong odor in the cabin/burning smell. At 2600 miles the MIL light came on agaiin, I took it to the dealer and they found the EGR Valve defective, they replaced it, (over a week in the shop). it seems much better now but I still have the smell at times. I have been told they are working on it but I don't think they have a solution. I have driven other Diesels, Mercedes ML Bluetech and VW Toureg, and though they may have some exterior diesel odors the smell doesn't enter the cabin with the windows closed. My neighbor has a VW no odor at all. My feeling is that exhaust system may have some leaks or the body/cabin may have some areas that let the exhaust fumes enter at times, i.e. backing up, exiting the Interstate or in heavy traffic.
A friend of mine works for a local dealer as a master tech. He said they had one with a leaking DPF tank or part of the DPF system and the parts were unavailable at the time when they went to order them. Maybe thats why it took 2 weeks
 

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Burning Smell

My Jeep Grand Cherokee Diesel has had this issue since new. I took it to the dealer at 300 miles , they couldn't find an issue. Finially at 1200 miles the MIL and DEF light came on. Took it to the dealer and they found the DEF Tank empty and the DEF Doser control leaking, they replaced it (was in shop for 2 weeks). That took care of the DEF leaking, but I still had a strong odor in the cabin/burning smell. At 2600 miles the MIL light came on agaiin, I took it to the dealer and they found the EGR Valve defective, they replaced it, (over a week in the shop). it seems much better now but I still have the smell at times. I have been told they are working on it but I don't think they have a solution. I have driven other Diesels, Mercedes ML Bluetech and VW Toureg, and though they may have some exterior diesel odors the smell doesn't enter the cabin with the windows closed. My neighbor has a VW no odor at all. My feeling is that exhaust system may have some leaks or the body/cabin may have some areas that let the exhaust fumes enter at times, i.e. backing up, exiting the Interstate or in heavy traffic.
JasksJGC
Had the same problem a few weeks ago on my 2013 Grand Cherokee 6000 miles UK Scotland. Burning smell coming through the vents around 30 seconds after start up. Dealer checked it and said they could not find a problem. I did not accept this and kept at them, I also made them aware that my wife had been to the doctor with a persistent chough and that I thought this odour may have been the cause. Car was back in the garage, it took a week to locate the fault which turned out to be a faulty EGR Valve. Took another week to order the part and replace. Turns out that the seal had gone on the EGR and it was pumping exhaust gas into the engine bay which was in turn sucked through the air vents into the vehicle interior. There were no warning lights just the burning smell. Seems to be fixed now, but very worrying to think my wife and I could have been driving around breathing in toxic gas for God knows how long. Hope you've got the problem rectified.
 

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We got our 2014 GC a few months back and it is at 6000 mi now, in the past two months the dealer had to replace the front wheel bearings and couple of engine sensors. During the replacement of the sensors, they had to take the turbo apart. This took them two weeks. In any case when they put the turbo back together, the mechanic try to re-use a clamp. After getting the car back on Thursday nigth and my wife suffering the next with nauseous smells in the cabin I took back to the dealer. The result after was that the clamp was a one time clamp and could not be re-used. Exhaust gases were coming into the cabin via the cold air intake, fixing this took them another week. We figure it was all done, but then this weekend we put 1600 mi and we could not keep the windows close and the air running. The same time of smell was coming in a making me nauseous. The car is back at the dealer today.
 

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Purchase my GC diesel on 12/31/13. As of today I have 21,500 miles. I too had this smell / order in the beginning. I would call it an ammonia smell which from what I have read comes from the processing of the DEF in the exhaust system. At about 8000 miles the smell went away and the DEF consumption went down. Not sure why? Dealer installed software updates when I had the oil changed, maybe that did it, or did the computer change something after so many miles? Don't have the ammonia anymore.
 
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