Rotten Egg-like smell coming from '96 Saab se turbo

eawegeaweg Member Posts: 50
edited March 2014 in Saab
Anybody...for the past couple of weeks I seem to notice a rotten-egg like smell coming from my car. I notice it after I have been driving for about 15 minutes...especially when I park it in a garage (non open area). The smell then goes away after about 2-3 minutes. What gives?


  • jgmilbergjgmilberg Member Posts: 872
    Could be a bad catalytic converter, I had one that was bad made the exact same sulfur smell. Do you only smell it in the car, or outside the car. If inside the car is it when you are stopped at a light? How many mile on the car?
  • eawegeaweg Member Posts: 50
    I too thought it was the catalytic converter. I only smell it when I get home or when I get to work. I haven't noticed it a stoplight .I have 50K miles on it and it passed inspection last week. The car is in great shape. I had a transmission rebuild last year and a rear and center muffler replaced.

  • Mr_ShiftrightMr_Shiftright Sonoma, CaliforniaMember Posts: 64,482
    If it's a turbo you could be cooking your battery. Is the battery still next to the turbo on this year Saab. I just can't recall offhand, but earlier Saabs had a battery-cooking problem.

    Othewise, almost certainly a catalytic issue of some kind....this is hydrogen sulfide I believe? Chemists on board?
  • joe3891joe3891 Member Posts: 759
    will also cause the exhaust to smell.
  • dhanleydhanley Member Posts: 1,531
    Ok.. In europe, there are certian sandards for how much sulphur can be in fasoline. In the U.S. we allow quite a bit more.

    The euro cats are designed for the lower sulphur gas. What happens it that the sulphur builds up on the cats, and it tends to dump off the sulphur en masse.

    What happens chemically is that extra fuel in the exhaust gets seperated into its components by the catalytic converter, and some of the free hydrogens combine with the sulphurs to make the rotten egg molecule. This will obviously happen more than the engine is running rich. SAABs run rich when there's significant boost.

    'course, it could be something else too, but it's not unusual on the euro cars, especially if you live in the southwest, because a lot of our gas comes from south america, where the sulphur content is very high.

    BMW's had a few problems with the sulphur, too.

  • bretfrazbretfraz Member Posts: 2,021
    I have a '00 9-5SE V6 and I smell it all the time. I believe Dave's comments are correct. Too much sulphur in US gasoline which the catalytic converter can't handle.

    If you've noticed this recently, you might want to switch brands of gas. I've noticed with BP the smell is lighter. It's stronger with Amoco, Chevron, Texaco and Quick Trip/Speedway.

    Also the time of year and US region has something to do with this. The midwestern states use more gasohol than other states. Northern states get a reformulated gas as winter hits. Californis doesn't sell any gasoline. They use a "vehicular propellant" that is made of filtered spring water, sushi juice, and the liquid leftover from fresh salsa. Talk about a strange smell...........
  • jgmilbergjgmilberg Member Posts: 872
    Actually when a company imports a car it has to meet fedral emissions standards and that would includes the cat. I work at GM and the cars we export have different cats for every region. Did you know that in the Mid East they are still usin leaded gasoline?!
  • ghuletghulet Member Posts: 2,628
    BP and Amoco are the same gas, that's why it's now called 'BP Amoco'. As a Saab owner, I predict the rotten egg smell is your warranty cooking, telling you that you're in for major stinky-priced repairs. Sorry.
  • bretfrazbretfraz Member Posts: 2,021
    I'm covered under 4 yr/50K warranty. No worries here.

    I still think Dave is essentially correct. Saab has had issues with their ECU's. My 'sperience is that the smell is most noticeable after some spirited driving. When I drive it easy, not much stank.

    I do think the smell is a combo of excess sulphur in some fuels, a cat that meets EPA regs but doesn't handle sulphur too well, an over-rich ECU programming, and some turbo-spinnin' fun on my part.

    It's no big deal to me. It stinks but I can live with it.
  • eawegeaweg Member Posts: 50
    Everything you all have said makes sense! I will make the change in brands and see if it works.
  • dhanleydhanley Member Posts: 1,531
    Just because the ECU does funny things with sulphur dosn't mean it's bad.

    The car runs rich under high boost because running rich is a way to stop preignition in the high pressure & heat environment of high boost. It's not an ECU problem per se.

This discussion has been closed.