Exaust Smell?
 

Hey guys and gals! I own a 08 f150 and have about 1000 miles on it and notice a rotten egg smell from the exaust. More noticable during a period of 50 mph drives and then stopping. I know this smell is from the cats but is this just a normal thing for these trucks?

I remember in the 80's-early 90's a lot of gas vehicles smelling like that. Long time since I have smelt that but ever once in a while I do.

Did it just start?

Did you fill up from a different gas station?

I had it once at about 2k it was there for a couple of days then gone.

Lars

If it keeps it up take it back to the dealer.

Isn't that smell from sulfur in the fuel? Lars! You remember the same thing I do! I got it in gas from a Chevron station back then. I stopped using Chevron when that happened and I still feel "queasy" every time I'm sort of "forced" to fill up at a Chevron station on trips, because my tank is low and that's what's available.

About a week ago, we were driving back from a trip with our grandchildren and I smelled it again. Once we all figured out it wasn't one of us, :hehe: I decided it had to be sulfur laden fuel again.

- Jack

My 05 and my 08 both stink to high heaven...My cousins 08 does it as well so i figure its either the local fuel or just the trucks...

I'll try filling up at a different station next fillup and see if it helps.

That one time I did fill up was at a mom+pop station that had an indepent hauler. Usually I fill up now at the name brand ones only.

Yes Jack sulfur is that smell.

Lars

Hmm, i live in a town of about a million people...not too many mom and pop stations and it still smells really really bad...On the other hand, 8 out of 10 times i fill up at walmart/sams...cause they are usually 6-10 cents cheaper and that adds up when im putting 27 gallons in...Thank god i didnt get the 36 gallon tank.

I don't think the sulfur content is really a function of the brand of gas. As far as I know, it's not a "regulated" substance, so refineries don't have to go to the expense of removing it. It's present in crude oil, except "light, sweet" crude, which comes from Saudi Arabia, is supposed to be very low in sulfur.

I suspect any brand you buy could be high in sulfur at any given time.

- Jack

So the sulfer content is all dependent on which refinery and where they are getting the oil from to be processed. Not to argue with Jack but sulfer is regulated in diesel so it must be too in gas. Probably not as much in gas.

Lars

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: