Learning a little more about how to better care for your vehicles is a good idea for any number of reasons. It allows you to know if an unscrupulous mechanic is attempting to gouge you on your repairs – and that will save you money. It can prevent you from making unnecessary repairs – and that will save you money. It can help you locate a problem and fix it early, thus saving more money – sometimes a whole lot of money. It allows you to be more independent in an era where people are entirely too dependent on others to survive. We need to get started now, so that we have time to cover everything… It may sound strange that smelling your vehicle can be a useful maintenance activity, but believe me it is. And I'm not just talking about needing to buy one of those cute little green trees that permeate every inch of your vehicle's interior with the smell of pine – or something like that. Actually, you really already do this in at least one instance – the smell of gasoline. And we'll cover that herein. Let's begin with the smell of smoke. If your vehicle is smoking anywhere at any time it's time to get some service – immediately. It doesn't matter if you smell the smoke, or see it – you need to deal with the problem ASAP. Smoke coming from anywhere is never 'okay' in a vehicle, though you may just have some spilled fluids on a hot engine surface, or some oil that splashed into your wheel assembly. No matter – get it checked and make sure. The smell of gas is most often associated with a flooded engine: too much gas for the spark to ignite. The gas sits in the engine, and the odor becomes more noticeable for a short time, and then starts to rapidly dissipate. This tends to happen only when you are starting the engine. The smell of gas at any other time, or the constant smell of gas is indicative of another type of problem, and one that is potentially serious, or dangerous: a leak in the fuel system. You should have this checked out by a qualified mechanic as soon as possible. The smell of rotten eggs, usually associated with sulfur or burning sulfur, is likely a problem with your catalytic converter. Servicing a catalytic converter is highly technical, and will require the attention of a trained technician or mechanic. You should make an appointment for your vehicle as soon as possible. A maladjusted or failing catalytic converter can be costing you precious mileage! The smell of burning bread, sometimes referred to as 'burnt toast,' is most often associated with an electrical short circuit or possibly the burning/melting of the insulation around the affected wires, fuses, or connections. If there are any secondary signs, then you should not run the engine until a qualified technician resolves the issue. Left unchecked, electrical shorts can affect many of the systems in your vehicle. A sweet odor, especially when mixed with the smell of hot rubber, usually means there's a coolant leak, or a problem with the cooling system. If you are driving, stop and visually check the engine and the radiator. Driving a vehicle with an overheated engine can do untold damage to all sorts of things, and turn a simple repair with a modest cost into a nightmarish expense that prevents you from using your vehicle for days, or even weeks. The smell of burning oil is a pungent, acrid stench that can be very slight, or quite pronounced. In either case, you need to check your engine to make sure you don't have an oil leak, and also to ensured that you have the recommended amount of oil in your engine. Usually, the smell of burning oil is something minor, such as a small spill on the engine, a slight overflow that got blown onto a hot engine part, or low engine oil. Be sure that when you change your engine oil you insist on an Engine Sentry®. Okay, you've completed the final step in becoming a full-fledged automotive diagnostician – or something like that, anyway. You've definitely gotten your vehicle in much better condition, and you should have learned a thing or two to keep it running great for a long time to come. If you haven't already, check out Part I – See No Evil, and Part II – Hear No Evil.