The alternator drive belt connects the engine and the alternator to charge the battery. If the belt is loose, it can slip, making the alternator work harder. This can cause problems with other accessories like power steering, A/C, and the water pump and may lead to symptoms like hard steering, poor A/C performance, and overheating.

If you notice a check engine light on the dashboard, squealing noises, lights dimming, the vehicle harder to steer, or no lights on the dashboard, save this information; they're essential if you go to an auto shop later.

The ECM (Engine Control Module) is the brain of the engine and powertrain. It controls the engine's air and fuel flow and cylinder firing time. The ECM uses input from sensors on the vehicle to make these decisions. If the ECM receives correct inputs but doesn't send the right outputs, the check engine light activates, and the car may underperform. For example, if a coil driver, which sends signals to the coils, fails, it causes a cylinder misfire, activating the check engine light.

If you notice the vehicle shuddering, losing extra fuel, limited to certain speeds, the engine stuttering, or underperforming, save this information; they're essential if you go to an auto shop later.

The motor mounts are essential parts of a vehicle that reduces the shaking and movement felt while driving. They do this by isolating the vibration from the engine through a rubber structure. However, that rubber can wear and tear down over time due to temperature changes. When you put your car into gear, it applies rotational force to the engine. If you stop the vehicle with your foot on the brake, this force is absorbed by a torque mount component. If the torque mount's rubber has torn or worn out, it'll make a noticeable clunking sound when you shift gears.

The brake caliper piston has a dust boot to remove dust and debris. It also has an o-ring that seals the fluid and acts as a return spring. If dirt or water gets in between the piston and the bore, it sticks, causing problems. Brake fluid contamination can also cause rust and debris, leading to a sticky piston. This results in excessive heat, warped rotors, and a vibrating steering wheel when braking.

The car's engine runs on large quantities of oil. So, it has various sealings to ensure none of its oil leaks. However, through wear, tear, and age, these sealings can become weak, loose, or cracked.

A deteriorated sealing component in the car's engine is one of the most common causes of a burning oil smell. In this case, these components leave small cracks and gaps for oil to seep, causing oil seepage. Then, the oil falls into hot parts of the vehicle, burning and leaving a smell.

The A/C has components like the blower motor, which are vital to its operation. The blower motor helps move air through the HVAC (Heating, Ventilation, and Air Conditioning) system. This component is part of the electrical system and has various wires and connectors around it.

The blower motor wires will overheat when using the heater while the cabin air filters are restricted. The air filters can become clogged with dirt, especially if they're too old. Then, the overheating will burn nearby plastic components, causing a smell through the heater and A/C system.