* Engine bays are different between models of cars, however, most cars in the same class are similar enough that if you know your way around one you will be able to find your way around another.
This episode features a 1996 Ford Ranger with the 4.0L V6 OHV Cologne engine. Click on the photo for a higher resolution view.
- Engine Oil Cap
- Engine Oil Dipstick
- Transmission Dipstick
- Radiator
- Radiator Cap
- Upper Radiator Hose
- Engine Coolant Reservoir
- Windshield Washer Reservoir
- Fuse/Relay Box
- Battery
- Air Filter Housing
- Mass Air Flow Sensor (MAF)
- Brake Fluid Reservoir
- Brake Booster
- Power Steering Reservoir
- Spark Plug Coil
- Idle Air Control Valve (IAC)
- Alternator
- AC Compressor
- Serpentine Belt
In this photo, you can see the basic maintenance items common to most cars. Below is a brief description of each component outlined in this episode and, if applicable, any quick and easy maintenance checks you can perform on the component.
Engine Oil Cap - Add oil here
Engine Oil Dipstick - Use to periodically check the oil level in your engine. To check, remove the dipstick, clean it with a rag, and fully reinsert it. Remove the dipstick again and note the level of oil. If the oil is in the cross hatched area it is ok. If it is below, slowly add oil through the Engine Oil Cap until the oil level is within the cross hatched area.
Transmission Dipstick - To accurately check the level of the transmission fluid, you transmission should be at normal operating temperature. With the engine running, apply the brakes and move the gear shifter through the whole ranger of gears (i.e. P-R-N-D-2-1), waiting about 2 seconds at each gear. Move the gear shifter back to Park and check the dipstick while the engine is still idling.
Radiator - The radiator works to keep the engine from overheating. You can visually check the bottom for leaking coolant.
Radiator Cap - If the car has been used recently be very careful removing the radiator cap because the system will still be pressurized and hot steam could scald you. When in doubt, listen for a hissing sound when you turn the cap. If you hear a hissing sound, do not remove the cap. Otherwise, remove the cap and look at the coolant inside the radiator. If it is discolored (there are lots of different colors of coolant, so you will have to know the original color in order to know if the coolant's color is different) you may need to flush the cooling system. Also, make sure the radiator is full of coolant.
Upper and Lower Radiator Hoses - Visually check the hose for any cracks, holes, deterioration or any other signs of leakage.
Engine Coolant Reservoir - Check the level of coolant and make sure it is not above the "COLD MAX" line on the exterior of the reservoir.
Windshield Washer Reservoir - Check the level of the fluid against the line on the exterior of the reservoir or keep at least half full.
Fuse/Relay Boxes - To check a fuse, remove it and look through its side. If the wire connects the two prongs, it is good. If the wire is broken, the fuse is bad and should be replaced with a fuse with the same number.
Battery - Most auto parts stores can test your battery for free. Make sure the battery posts and wire terminals are clean and do not have any built-up corrosion. Corrosion will look like white, clumpy powder. To clean the posts and terminals, remove the negative terminal first, then the positive. You can use a wire brush, scrub pad, commercial battery post cleaner, or a 3:1 baking soda/water paste to scrub the battery posts and wire terminals clean. If you used any method that involved liquid or paste cleaners, allow everything to thoroughly dry before reinstalling the terminals onto the posts. Always reinstall the positive wire first, then the negative. You can smear a little petroleum jelly over the posts to help prevent future corrosion. (Note: after uninstalling the battery, the car may run slightly more rough than before because the car's computer's memory will have been reset and it will take a few miles for it to relearn its previous settings).
Air Filter Housing - The air filter is located in here. To access the air filter you will have to remove some clamps or screws (depending on the car). Pull the air filter out and visually inspect it.
Mass Air Flow Sensor (MAF) location - Inside the air intake tube (after the air filter) is the MAF. There is no regular check you can do, but if you ever need to clean the MAF due to a rough running engine, you can spray electronic cleaner spray over the wire.
Brake Fluid Reservoir - Visually check to make sure the fluid is at the proper level.
Power Steering Reservoir - Visually check to make sure the fluid is at the proper level. Some systems use a dipstick method of checking the fluid level.
Spark Plug Coil - Visually inspect for any cracks. You can also check the spark plug wires by looking for any small electrical arcs while the engine is running. You will need to do this in a dark (but well ventilated) garage or at night.
IAC Valve - If your engine in running erratically while idling, the problem may be a faulty or stuck IAC valve. To check, unplug the electrical wiring to the valve while the engine is running. If the engine's RPMs drop, the valve is working. If the engine shows no change then the IAC valve must be replaced.
Alternator - Most auto parts stores can check your alternator for free. The alternator basically converts power generated by the engine to charge the battery and run the accessories, like lights and radio. When the engine is not running, the lights and radio run off the battery.
AC Compressor - If the AC compressor constantly starts and stops but you are not getting any cold air, have the AC system checked for leaks or low refrigerant.
Serpentine Belt - Some vehicles will have one serpentine belt, some have two belts - one that drives the Air Conditioning Compressor and one that drives the Alternator, Water Pump, and Power Steering. Visually check the belts for frays, cracks or missing chunks.
