soot at exhaust - problem?

Hi All

I have a recently purchased 9-3 S Convertible with the HOT engine. I noticed on my garage floor that there are particles of soot...blown out of the exhaust at starting the engine. The chrome exhaust tip is black now too...does it sound like I have a problem or is this to be expected.

I am running on straight unleaded rather than premium unleaded fuel - will that be relevant?

Thanks In advance for your help, DAN

Reply to
indecisive
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A black sooty exhaust pipe is an indication for running a rich mixture or burning oil, in combination with smoke from the exhaust. What is the condition of the spark plugs? electrodes color?

yes, it is not as it should be.

no

No, the engine management system should take care of all that. I would take the car to a (SAAB) garage and have the engine checked.

-- MH '72 97 '77 96 '78 95 '79 96 '87 900T8

Reply to
MH

[snip]

I think it's fairly normal for a modern car. For instance, My HOT 9-3 has a fairly sooty exhaust too. It passed it's first MOT yesterday. Lambda was dead on 1, so it certainly isn't running any richer it ought to. It doesn't lose any oil either.

Cheers,

Colin.

Reply to
Colin Stamp

Thanks for the - disparate - views guys. The car has been serviced by SAAB dealer less then 3 weeks ago, when I purchased it. The next service isn't due for a year so I assumed that they would have checked the tuning at the service?

Reply to
indecisive

Don't you just love usenet :o)

They won't have. There is no check for mixture in the service schedule. They expect the closed-loop control system to keep it all nicely tweaked-up as you drive. For the system to not work and not be able to tell you that something is wrong, would require a pretty weird fault.

The backup is any mandatory emissions tests you might be subject to in your area.

Cheers,

Colin.

Reply to
Colin Stamp

You're probably not saving any money and you are losing out on a lot of power aka fun. When you use lower octane gas the engine will detune from ideal settings while you drive - reducing mileage by more than you save per gallon. I can't see the point of owning a HOT motor if you are going to use regular.

Reply to
Retro Bob

I would suggest to look into the manual under the hading Fuel and read SAAB:s own recommendations. In the manual for my 2002 9-3 Sport Edition there are recommendations for the different engine options (in this case

150, 185 and 205 hp)

/Bengt

Reply to
Bengt Österdahl

Interesting challenge there Bob...I'll fill up with premium next time and compare.

Certainly the fuel usage is poor at the moment (mainly city driving) at

12-13 litre per 100klm.

Reply to
indecisive

Be aware that ambient temperature ha a significant effect on MPG. Make sure your tests are valid.

Reply to
Retro Bob

You need to get you engine codes checked. There are ways to do it yourself but I am not familiar with yours. Bottom line is this, there are many "problems" fault codes that will not trip the "check engine light" My 9K was not its usual peppy self and when I checked the computer codes it showed a lean condition and "suggested " I check the O2 sensor. I never got a "check engine" light with that alarm. Looks like you are running a little rich.

Reply to
Monkey Wrench

This isn't the case with the 9-3 though. I thought the same as you until I needed a new SID programming for the car. I'd just serviced the car so I asked them to read out the fault codes (since I'm used to this being on the service schedule). I was told that there would be no point as the car won't store any fault codes without also complaining to the driver. They checked anyway, and there were no stored faults. When I got home, I checked on WIS and, sure enough, there isn't an item on the service schedule for reading fault codes.

As I said before, a slightly sooty exhaust seems to have been standard on all the cars I've owned with catalysts. It seems that the "lambda=1" mixture that's needed to keep the cat happy is, in fact, a bit rich compared to what was considered best on older cars.

Cheers,

Colin,

Reply to
Colin Stamp

Gee guys - you are so learned! Thanks everyone for the input. I feel like I belong to a club since I bought the Saab!

Reply to
indecisive

Yes, you do, and you will be buying more of them soon. It's a sect, an addiction, you are hooked...

-- MH '72 97 '77 96 '78 95 '79 96 '87 900T8

Reply to
MH

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