Thread Starter
#1
One thing I like to know is that at low RPM the Ritz sometimes gives out H2S kind of smell ( rotten egg ) . Why is this? My car has run 24500 Kms. ( 1 1/2 years old ) I did replace the Cataylist, ( by the service agency ) but still the smell is there some times.![[frustration]](https://www.theautomotiveindia.com/forums/images/smilies/Frustration.gif "Frustration [frustration]")
The smell emits from the tail end of the exhaust ( like normal exhaust ) . 1) The fuel used always is unleaded. 2) I did not change the fuel all these time. I think its something to do with the catalytic converter or else how come this kind of smell comes? Our authorized service could not solve and I got fed up with them. No point in wasting my time. I got a suggestion some time back and I quote "
" Ironically, the “weird odour” is a sign that your cat is working properly. As mentioned earlier its hydrogen sulfide which does come indirectly from the fuel. The fuel contains organic sulfur compounds ranging from 30 to 100 parts per million, approximately. As the fuel burns, the organic sulfur compounds break down into simpler compounds. If the engine is running lean (more air than fuel), the sulfur is likely to be sulfur dioxide. The catalytic converter can change this into sulfur trioxide, which then reacts with the cat to form sulfates on it. There will gradually be a build up of sulfates. If the engine suddenly starts to run rich (not enough air to burn all the fuel), such as when you brake at a red light, climb a steep hill, or brake hard to slow down, there is unburnt fuel which reaches the cat and reacts with the sulfates. The sulfate reaction with the unburnt fuel starts forming hydrogen sulfide.
This is the reason for the bad smell. This happens with new vehicles because the catalyst is working very well. However, as the car and the cat gets older, the efficiency drops and there will be no smell. This smell does not form in all new cars - one reason might be that the vehicle doesn't run lean for much time - no redlining. "
Please my dear Petroheads, help me so that I can explain in simple terms to my authorized service mechanic and solve this problem.![[confused]](https://www.theautomotiveindia.com/forums/images/smilies/Confused.gif "Confused [confused]")
The smell emits from the tail end of the exhaust ( like normal exhaust ) . 1) The fuel used always is unleaded. 2) I did not change the fuel all these time. I think its something to do with the catalytic converter or else how come this kind of smell comes? Our authorized service could not solve and I got fed up with them. No point in wasting my time. I got a suggestion some time back and I quote "
" Ironically, the “weird odour” is a sign that your cat is working properly. As mentioned earlier its hydrogen sulfide which does come indirectly from the fuel. The fuel contains organic sulfur compounds ranging from 30 to 100 parts per million, approximately. As the fuel burns, the organic sulfur compounds break down into simpler compounds. If the engine is running lean (more air than fuel), the sulfur is likely to be sulfur dioxide. The catalytic converter can change this into sulfur trioxide, which then reacts with the cat to form sulfates on it. There will gradually be a build up of sulfates. If the engine suddenly starts to run rich (not enough air to burn all the fuel), such as when you brake at a red light, climb a steep hill, or brake hard to slow down, there is unburnt fuel which reaches the cat and reacts with the sulfates. The sulfate reaction with the unburnt fuel starts forming hydrogen sulfide.
This is the reason for the bad smell. This happens with new vehicles because the catalyst is working very well. However, as the car and the cat gets older, the efficiency drops and there will be no smell. This smell does not form in all new cars - one reason might be that the vehicle doesn't run lean for much time - no redlining. "
Please my dear Petroheads, help me so that I can explain in simple terms to my authorized service mechanic and solve this problem.
