My dealer told me that it was just the smell of the cats breakin in, and it will eventually go away once they get "Tuned" to the exhaust temperatures. My truck did it for a little while and now it has stopped. Just my two cents. :cheesy smile:

Ouch! I'd forgotten about that! I DO think you're right about it being regulated, probably to prevent formation of sulfuric acid compounds, which ARE dangerous. And, I see from Wikipedia that some people can have deadly allergic reactions to it. However, we all know from chemistry lab days that it takes very little sulfur dioxide to make a stink bomb and you certainly smell it around geysers, volcanoes and even some hot springs.

I imagine our noses are very sensitive to even minute amounts of that compound - amounts that are below any regulated limit.

Thanks for keeping me humble and reminding me I don't know everything, Lars!

- Jack

Oh Jack, I am not trying to humble you. I just had a flash back to the early 90's when they started to make diesel "dryer". They took out a lot more of the lubrication of the fuel by doing this and a lot of those motors fell prone to failure.

Does sulfur create the same compounds when it burns regardless if it is spark ignition(gas) or compression ignition(diesel)?

Yeah the diesel pumps around here all say...(This diesel fuel is "ultra low sulfer highway diesel" or something like that...Our 07 likes it, but our 99 seemed to run better on the "dirty" stuff...Whats up with that lol?

DJ Soutthpaw may have a better grasp on this. But if you would like to compare it to leaded and unleaded gas. Here it goes: when unleaded hit the market in the 70's a lot of cars from then and on back started to experience head problems(valve seats and valves) due to overheating. Well they took away the lead that acted as a lubricant for those parts. So maybe sulfur and some of the other chemicals due to the reduction of them the same thing is happening in diesels. Have you noticed in the last 3 years they want diesels to burn hotter to get rid of more of the byproduct junk. That's on the exhaust end.

My truck has been doing it since new but I have noticed its not as bad as it was. Thanks for the feedback guys.

This "burning hotter" is kind of a "damned if you do, damned if you don't" thing. At least in gassers, hotter burning causes nitrogen, which is normally pretty inert, to combine with oxygen to form nitrogen dioxide, a toxic pollutant. I wonder if it does the same in diesels.

The EGR system in gassers was developed to cool the combustion process slightly to reduce formation of this gas. (Of course it also cuts power).

Oh, your earlier question Lars - I can't imagine why a diesel would not produce some sulfur dioxide if sulfur was present in the fuel.

- Jack

But why are the new diesels not able to run (at least not supposed to) run on the older style diesel? I ask because I live in El Paso TX which is a bridge away from juarez mexico. Anyway, last summer when diesel was like 4 bucks, many people were going to Juarez to fill up their trucks because diesel was only 2.19, and when you are filling a 100 gallons (nearly %50 cheaper) thats a lot of money. However, only guys with older trucks were doing this...we couldnt do this in our 06/07 whatever it is cummings...it really screwed up the newer trucks...whats up with that? What was so different.

Good question! Maybe cleatus12r or southpaw could jump in here. I know next to nothing about diesels (except that they use glow plugs for starting).

When I was a kid, I had a model airplane engine that was a "true" diesel - no glow plug! That thing was super hard to start. I seem to remember that it would also run backwards at times.

- Jack

yeah.....MY 08 is a stinky ***** too :eek:. I've wondered if it is my Magnaflo exhaust but don't know?
I had the exhaust installed on day 1 at the dealer when the truck was brand new......so I never got to smell the stock system!

Oh well.......you can't make good power without stinking :thumbs up yellow: