hard acceleration

[auto///m3]

everytime I accelerate really hard (floor the gas) there is a funny smell comming from my car. and once I stop and shut off the engine and walk out I can smell a burning scent from the car. on the other hand, if I drive normal, everything seem to smell normal. is this normal? mybe my o2 sensor is bad or what do you guy think is wrong with it. I also used only 91 octane. thanks in advance!

[Erik@EDGE]

what brand of gas are you using? If it is Shell, that is likely to be your problem. Our cars seem to like just about anything but Shell. Chevron is the best

[Nike178]

If it smells like rotten eggs, i experience the same thing also in my M3. Pretty common from what i been hearing. Most will say its the o2 sensor like u said. I havent changed mine but soon will. Try changing different brands of gas and put 93 octane

[pw455]

Originally posted by 95 MPWR
what brand of gas are you using? If it is Shell, that is likely to be your problem. Our cars seem to like just about anything but Shell. Chevron is the best

How does Shell stay in business with the crap gas they sell? I haven't run it in my M3, but I have on older cars without knock sensors. In those cars I've run everything from the cheapest Arco gas all the way up to 76 & Chevron. The only gas that has ever made it knock like crazy is Shell. The only time I will ever run Shell is if I'm about to run out of gas. I think the best gas out there comes from Chevron & 76.

Pete

[wewu]

I assume that if you are running your car hard, then I also assume your brakes are also taking a beating. So maybe it might be your brakes if it is a burnt smell. Also maybe check your oil level. If its a rotten egg kinda smell then its nothing to worry about.

Btw I once neglected to change the oil for like 5k-6k miles on conventional oil and almost every time I drove the car hard there was a burnt smell in my garage. When I finally got around to changing the oil it had a burnt smell to it.

[M3Buff]

Hey, what's up with Shell? Everybody but me seems to be aware of this. I use it pretty often cause it's next to my workplace, and my car seems to be running ok, and there's no knocking of any sort. Do I need to stay clear of em?

[B.Watts]

In my area, Exxon/Mobil fuel seems to be what makes my M3 smell. Shell seems to get rid of the problem. Regardless, if the fuel makes your cat smell, it doesn't mean the fuel is low quality.

[Dinan330ic]

auto///m3, you may be leaking oil. the oil can leak down the exhaust pipe and burn off. This is especially noticeable under hard acceleration.

[ASCH MAN]

I think it is all a rumor about Shell. It is all I have ever used and never had a problem. People here in Columbus say that BP is the worst for cars and can reduce performance with the detergents they use. All dealers around here say that Shell is the best.

Now that I hear people say that Shell is crap confirms my beliefs that Shell is probably just as fine as BP as everything else that is rated 93oct. It is all psycological!

[Ron17]

What kind of smell is it? Like a burning rubber scent? Like a burning oil scent? Like rotten eggs?

Let us know...

[Jgent]

Fuel is a commodity it's all the same. I was involved with a distribution company once. All the fuel is stored in huge tanks, the trucks come and fill up on the gas, pretty basic but there is a point to this. The brand name on that truck dictates where the fuel is going and what it is going to be sold as. In the Boston area if you buy Citgo, Mobil or a no name brand it is all the same it came from the same tank. Same goes for other "brands".

[pw455]

I don't have anything against Shell except for the quality of their gas. I'm not sure how my M3 would act if I used Shell gas. I imagine that if everything in the car was working right, the only difference would be in power because of the timing backing off when it knocks. I also have a '91 300E Mercedes and an '89 Mazda 323. Both of these cars run fine on regular gas, unless I use Shell. With Shell, they both rattle like diesels when I floor them. It doesn't happen with any other gas I've used and I've tried pretty much all the brands in my area. I would like to see back to back dyno results with Chevron or 76 against Shell. I'm sure there would be a drop in power with the Shell.

Pete

[pw455]

Originally posted by Jgent
Fuel is a commodity it's all the same. I was involved with a distribution company once. All the fuel is stored in huge tanks, the trucks come and fill up on the gas, pretty basic but there is a point to this. The brand name on that truck dictates where the fuel is going and what it is going to be sold as. In the Boston area if you buy Citgo, Mobil or a no name brand it is all the same it came from the same tank. Same goes for other "brands".

Jgent,

I'm sure you're right on this to a point. A lot of the generic brands are basically purchased from one of a few main companies. However, Shell has their own refineries, as does Chevron, BP, etc. Here's a link to refineries in CA:
http://www.energy.ca.gov/oil/refineries.html

[pw455]

I found this on another forum concerning the rotten egg smell. I vaguely remember this from auto shop, but here are the details:

"The sulphur smell from the exhaust, is actually caused by running the engine/cat convertor slightly lean for long periods and then running under a rich condition (ie going up a hill under heavy load) This is when the sulphur smell (rotten egg) is produced.

Under relatively lean conditions, the sulphur found in gasoline is converted to sulphur trioxide, then during the rich running condition the sulfur trioxide is converted into hydrogen sulphide (rotten egg smell) within the catalytic converter.

The automotive stores should have a simple solution for under $7.00 that you pour into your gas tank that will help solve that problem.

The other way is switching gasoline brands may help. The Oxygen sensor may also need to be replaced to correct a fuel injection mixture problem.

** Live in Northern California? Go here. ** "

Here's the actual link:
http://forums.prod.legend.org/second/msgs/15725.phtml

Pete

[Jgent]

Yes, the oil companies have their own refineries. They also have supply and swap agreements with each other. What this means if one of the tanks is empty or they don't have a tank in a particular area they will go to one of the tanks in the area that have an agreement with and fill up. Also means that in various areas of the country they will share the same tanks (for example Mobil, otherwise known as liquid gold in the petroleum industry because they charge so much more than anyone else does not have a supply tank in the Boston area so they use Citgo's). The additives that you here about in the ads is mostly hype and only represents a tiny miniscal % by volume.

I use to look at the invoices and swap agreements as part of my job. Pretty amazing industry.

[pw455]

Sounds pretty interesting. I guess it varies depending on geographic location. Maybe I should change my statement to "In the SF Bay Area, Shell gas is crap"

Pete

[Dinan330ic]

Originally posted by pw455
Sounds pretty interesting. I guess it varies depending on geographic location. Maybe I should change my statement to "In the SF Bay Area, Shell gas is crap"

Pete

No wonder it's so cheap relative to Chevron

[CABimmer]

If you live in CA, you need to be buying from 76. They are the only gas stations (state wide) to not be using MTBE to raise octain. My car runs much better on 76 ater I made the change from Chevron.

[NiTE]

Originally posted by pw455
Sounds pretty interesting. I guess it varies depending on geographic location. Maybe I should change my statement to "In the SF Bay Area, Shell gas is crap"

Pete

OT, but WOAH another member from NH. Where in NH are you located?

[Ken ///M3]

BMWs require a clear, unrestricted vent tube from the battery to the outside via a small hole near the spare tire. On hard acceleration the acid in the battery can be forced into the vent tube and if it's restricted the gas can vent into the passengers compartment. It is a sulfur-based gas, of course and smells like "rotten eggs". Just take a look to see if the vent tube is in the hole and is free flowing. (use a small wire, not your mouth).

Ken

[Hellrot]

How old is your car?
How long have you owned it?
How long have you been noticing the smell?

When I got my car it was 3 years old and had 40k. But I started smelling hot cosmoline after I would drive it "normally". :evil2 My guess is the first owner drove it too slow and never got it hot enough to burn the "new" off of it. It's fine now.

[M3325]

Is your clutch relatively new? Worn clutch produce burnt smell quite easily.

[Estoril ART]

I too smell something from my car after I park it, but this is usually after I drive it in the highway, and I haven't been beating up on the brakes on these instances (calm, normal driving). So I first thought it was the brakes, but it can't be. Time to start driving it hard to burn all the carbon deposits :D