Ok, whats the story with the rotten egg smell. Often when I stop at a traffic light the car starts to stink like rotten eggs? Is this something the dealer can correct? Is it a gasoline issue?

Oh yeah, I have the V-8 and am getting around 7 miles per gallon pure city and 16-17 pure highway. A far cry from what the window sticker said. Is this gas mileage average for this car?

Ok, whats the story with the rotten egg smell. Often when I stop at a traffic light the car starts to stink like rotten eggs? Is this something the dealer can correct? Is it a gasoline issue?

Oh yeah, I have the V-8 and am getting around 7 miles per gallon pure city and 16-17 pure highway. A far cry from what the window sticker said. Is this gas mileage average for this car?

It's probably from the chickens under the hood ....

Seriously, something is up with that. Our 2004 V8 has nothing but that new car smell.


There is a thread somewhere on MPG of everyone's car for your comparison. Your's sounds like the worst performance I've read.

I had the same problem. Did you just get an oil change?
It started hapening after we got all of our gaskets replaced after the gasket recall. We managed to blow out just about all of them and were luckely in the shop the next day when they discovered it. It stoped after about 100-150 miles after the gasket replace.

BTW: i started that MPG thread. Its on pg.2 on the forum.

No, the car is about 3 months old with about 3,000 miles no other problems...just stinks from gas station to gas station. What was the gasket recall?

As I suggested in the other thread where you posted this issue, there is likely an engine-related problem. It could be something that has affected the timing (like the computer module), the injectors, or whatever. Rotten eggs is usually a sign of inefficiently burned fuel and/or malfunctioning catalytic converter. With the former, your mileage will be correspondingly terrible. It often happens in new cars - usually briefly at start up - but then disappears in time and usually doesn't cause much of dent in the mileage.

If the smell is persistent, get it attended to quickly as it could be a sign of more serious damage or, if it is the fuel-air mixture that's the culprit, the rich exhaust won't help your catalytic converter any. Either way, get it looked at PDQ.

Somehow, I doubt it's a gasket issue. Could be, of course, but doesn't sound right to me. Of course, these new engines severely strain any knowledge I've accumulated over the decades... :rolleyes:

Good luck

the car is still under waranty...right?...use it...that is what it is for.

I believe I know what the problem is. I had precisely the same problem when my CTS-V was brand new. It was a horrible odor, especially when I came to s stop. The problem was a short in the battery itself, the odor coming from burning sulphuric acid. The dealer replaced the battery (no charge) and the car finally smelled like new. Ask your dealer to run a battery check -- I think you'll find that's what the problem is.

Thanks for the tip. I am bringing the car in next week. I will get the battery checked although the battery seems to be working OK. Were you having battery problems other than the smell?

Typical, the dealer told me to get different gas!:banghead:

Have not had any smell problems. Not taking sides, but would have suggested a different gas as well. Perhaps a BP/Amoco or Shell product. Some stations where I live add 10% alcohol which I personally try to avoid. An engine that is designed to perform on 93 octane yet will burn 87 without spark knock is a great engine indeed. I think the least I can do is give 100% gas.

Of course you may already be using 100% gas and from a premium supplier, so my note is then null and void.

I can't remember ever hearing about good or bad gasoline making a different odor. I would not take the vehicle back to any dealer service dept that kicked the tires and came out with the BS about changing gasolibe brands. I would also ask to see the certification (if any) of the techs.i

Overly rich mixture = egg smell...

Know issue (mixture) with the V8 that have the stalling problem.

New firmware available last few days.

SYROB

Rotten egg smell is sulphur dioxide. The two possible sources for the sulphur are a lead acid battery or high sulphur gasoline.

Not exactly Sulfur Dioxide:

Sulfur dioxide (SO2) is created from small amounts of S in the gas. In the cat it can be oxidized to Sulfur Trioxide (SO3), which then forms H2SO4 (sulfuric acid) which forms hydrogen sulfide gas an this is where the smell comes from. Rich mixtures can lead to this formation, as can other conditions in the cat..

In other words the rotten egg smell is caused because while running under lean conditions the sulfur found in gasoline is converted into sulfur trioxide during the combustion process.

Then under relatively rich running conditions, idling or full throttle acceleration the sulfur trioxide is converted into hydrogen sulfide within the catalytic converter. It is the hydrogen sulfide that has the rotten egg smell. Hydrogen sulfide (HS) is a colorless gas that reeks of rotten eggs.

SYROB

Not exactly Sulfur Dioxide:

Sulfur dioxide (SO2) is created from small amounts of S in the gas. In the cat it can be oxidized to Sulfur Trioxide (SO3), which then forms H2SO4 (sulfuric acid) which forms hydrogen sulfide gas an this is where the smell comes from. Rich mixtures can lead to this formation, as can other conditions in the cat..

In other words the rotten egg smell is caused because while running under lean conditions the sulfur found in gasoline is converted into sulfur trioxide during the combustion process.

Then under relatively rich running conditions, idling or full throttle acceleration the sulfur trioxide is converted into hydrogen sulfide within the catalytic converter. It is the hydrogen sulfide that has the rotten egg smell. Hydrogen sulfide (HS) is a colorless gas that reeks of rotten eggs.

SYROB

A giant bingo to Syrob.

Plus, this is typically not good for your cat in the long run.

Ok, guys, help me out here. The dealer keeps going on and on about the gas, yet he can't tell me what is wrong with the gas or where to buy better gas, or what brand or Octane will make the smell stop. Does the car have a diagnostic the will say if the mixture is too rich or lean under different running conditions?
Not exactly Sulfur Dioxide:

Sulfur dioxide (SO2) is created from small amounts of S in the gas. In the cat it can be oxidized to Sulfur Trioxide (SO3), which then forms H2SO4 (sulfuric acid) which forms hydrogen sulfide gas an this is where the smell comes from. Rich mixtures can lead to this formation, as can other conditions in the cat..

In other words the rotten egg smell is caused because while running under lean conditions the sulfur found in gasoline is converted into sulfur trioxide during the combustion process.

Then under relatively rich running conditions, idling or full throttle acceleration the sulfur trioxide is converted into hydrogen sulfide within the catalytic converter. It is the hydrogen sulfide that has the rotten egg smell. Hydrogen sulfide (HS) is a colorless gas that reeks of rotten eggs.

SYROB

What is the firmware you are referring too?

Overly rich mixture = egg smell...

Know issue (mixture) with the V8 that have the stalling problem.

New firmware available last few days.

SYROB

So bottom line is it isn't some bogus cause such as "bad gas". And the dealerservice department is full of something that smells as bad as the Sulfur trioxide.

Wow... this is one of the worst dealer service stories I have heard in a while... BAD GAS? You have got to be f-in kiddin me. Please take the vehicle to ANOTHER Cadillac dealer and tell them you will not stand for such utter BS. You need to be firm or else youll likely get another run around elsewhere. The more important issue here is 7mpg city gas mileage, thats absolutely absurd, I mean the RAM SRT-10 gets 9!

I agree that gas with a high sulfur content would exacerbate an existing problem mixture problem but that doesn't rule out the fact that there's likely an underlying problem that makes the mixture too lean. Who knows - it could be something as simple as fouled injectors (but in an engine that new???). Personally, I would try to eliminate the seemingly stupid "bad gas" argument and run the car on premium from a different supplier for two tankfuls (about a week and a half for me!) and I would reset the mileage calculator at the beginning of each tank. But I'd be surprised if either the mileage improved or if the smell went entirely away. However, depending on how that went, I'd either go back to my original dealer with an ITYS or I'd find a new dealer PDQ - and I'd write an exceedingly polite (???) letter to the owner of that dealer explaining how they lost a customer.

Had the same problem with V6 SRX when it was new. The battery cover would get very hot to the touch. With some persuasion, dealer replaced the battery, and the problem went away, until yesterday. Once again had problem starting the car with burning smell. NOT BAD GAS. Good luck. Justin

Sounds like it may have an oxygen sensor with a slow response rate. The engine has 4 sensors, and if one of them is responding slowly, but still working, it may cause this. Also, there is a pcm software update for hard/no start cold due to excessive fuel feed on starts in cold ambient temperatures. Does the service engine soon light come on at all?

Flaufercaddy... YES, TAKE YOUR CAR TO ANOTHER CADILLAC DEALER.
I drove my SRX V8 from Houston TX to L A, CA then to San Jose, CA, then to Denver, and back to Houston TX in December. A total of over 5200 miles in 10 days. My average mpg was almost 19 for the trip. I was driving between 85 and 90 mph on highway. The car has over 15,000 miles now. I think it was very good especially I had 4 adults and a full load of cargo in the back. (I was taking my son back to University of Denver after visiting relatives in CA). My gas mileage in city (Houston) is near to 16. Although my 1998 Concour is almost 22 mpg on highway and 17 mpg in city, I think the mpg of my SRX is not bad. I had 2 other Cadillac (1981 DeVille and 1986 Seville) before the 3 (the other one is 2001 Catera) now I have. All of them have reasonable good gas mileage. There is a problem with yours. If your car is mostly stopping in the traffic, like the most famous Katy Freeway traffic jam in Houston, then it could be 7 mpg. Otherwise I think the mpg should be a lot better. If your dealer tells you to change the gas, give him $30 and fill up the gas from his shop. See what he is going to say. Good luck! BTW, no cars should have that rotten eggs smell. I like my dealer here in Houston. My advisors are very helpful.

I agree, somethin's not right. If only the dealer could figure out what it is. Today on Highway, 60 mile trip, 65mph, 16.5 mpg. BTW, I noticed that when the car is coasting at high speeds 50+ mph, the tach stays at 1800-2000 rpm even if your foot is not on the gas, if I tap the brake it will drop down to 1000-1200. Does everyone else's work like that?

the bad egg smell is most definately from the battery. if you pop the hood and smell around it should be coming from the passenger side, and it is likely strongest around the battery. mine was (today). so i pulled the battery and sure enough, the vents were smoking this aweful egg smelling stuff. there it is.
i am printing this thread to bring along to the dealer so they dont tell me the freaking bad gas story!
bk

Are there brown stains in your underwear and on your drivers seat? That could be the cause of the smell.