this may clarify it more.
Any type of engine smell is a bad sign, no matter what type of smell it is. A certain engine smell can be caused by a specific problem in your car. It is important you understand and know what each smell signifies and how you can fix them.
Types of Engine Smells
If your engine has problems, it might provide a certain kind of smell. Each smell can equate to specific problems in your engine. A burning engine smell like burned toast, which often emits a sharp, light odor, may be due to the insulation of your car burning or an electrical short.
Another common smell is similar to rotten eggs. Unless you have rotten eggs in your car, this smell is a burning sulfur smell which is a clear symptom of a catalytic converter problem in your engine, or damage in the emission control system. It may also mean that your engine is running with a rich air/fuel mixture.
If your engine emits a chemical odor or burning resin, then this may be due to an overheated clutch or brakes. On the other hand, a steamy, sweet odor is due to a leak in the coolant system.
Effects of Engine Smell
Once you can smell a different odor emitting from your engine, it is time to do some investigation and bring your car to a professional or do the necessary repairs. It is important to remember these smells mean there are damages or malfunctions to parts of your engine that need to be repaired.
Since each smell is due to a certain engine problem, it is important you immediately fix it. Otherwise, your car’s engine and overall performance will be affected.
Having a rich air/fuel mixture can cause your car to produce a higher level of carbon monoxide, which in turn can increase the production of carbon dioxide. This also means there is a leak in the injectors, the oxygen sensor is contaminated, or fuel pressure on the engine is excessive.
Although troubles in the catalytic converter may be hard to diagnose, the smell it emits is a surefire way of determining there really is a problem you need to address. The catalytic converter is a part of your car’s exhaust system, which converts harmful compounds to harmless ones.
How to Fix Engine Smells
For engines emitting a burned toast-like smell, it is safer not to use the vehicle until the damage has been repaired. Bring your engine to a professional to rid of the auto repair smells. Fix the electrical short or the burnt insulation.
A sulfur smell means there is a problem with the catalytic converter. To fix this problem, cut the damaged converter on both ends. Make sure the engine is totally cooled before you do this. After cutting the old one, replace it with the new converter and tac-weld each end. Remember that any damage to the converter should be repaired as soon as possible.
Most overheating problems on the clutch or brakes can be easily fixed. Check the thermostat of your engine, and if this is the cause of the problem, replace the thermostat with a new one.