Car Care 101
Mary Nohr
 
Checking things out under the hood
 
Mary Nohr with Bonnie Fancy
Images Stephan McKeown and Richard Simonds
 
Through the Ladies of Mercedes lifestyle program at Startech 2015 in Cincinnati, Mary Nohr, mechanic and owner/operator of Nohr’s Auto Haus Inc. service shop in Buellton, California, presented a for-women-only seminar on basic car care. In the first of two articles, we’ll summarize the tips Nohr offered her students as she gave them a guided tour under the hood during the first session.
The first thing they learned was that everyone should keep the owner’s manual, a small flashlight, a pen, a small notebook and a tire gauge in the glove box. Each woman received an information card to fill out and store in the glove box as well: The information should include the car’s make, model and VIN; oil type and grade required; fuel-octane rating; type of power steering fluid needed, recommended tire pressures and towing instructions.
Nohr emphasized that fluids and mechanical details should be checked at least once a month. Better still: Make a habit of performing underhood checks every time the fuel tank is refilled. If the car hasn’t been driven in some time, she said, it’s even more important to check these items before driving the car. Checks should be made with the engine off and the car on a level surface
Popping the hood can be a challenge. The hood latch release is located under the dash to the left of the steering wheel. Pulling the lever opens a primary latch allowing the hood to pop up slightly. There is a safety latch that keeps the hood from flying open if the inside latch is released accidentally. Raise the hood sufficiently to slide one hand underneath to reach the safety latch, pull it outward or upward, and raise the hood. To close the hood, put two hands evenly on the front edge and slam the hood moderately hard, or simply drop it from about six inches above the car.
Checking the oil      
   
Most models are equipped with an oil dipstick, which has a handle or grip that is usually red in color and markings at the lower end to indicate the oil level. To get a correct reading, check when the engine is cold, or wait until it has cooled down (about five minutes) and the oil has drained into the oil pan.
To check the oil, pull the dipstick out and wipe it with a paper towel. Reinsert and pull it out again and read the level. On most models there is a MAX (maximum) and MIN (minimum) fill mark on the dipstick. If the level is at the MIN or lowest mark, add one quart.  If it’s halfway between MIN and MAX add one half quart. Do not overfill. Consult the owner’s manual to determine the recommended oil-change interval, and the oil change sticker or oil-change records in your maintenance book to find out when the oil was last changed.
For a brief period from 2000 to 2010, Mercedes-Benz eliminated the manual oil dipstick. If you can’t locate a dipstick, check the owner’s manual. You may find that oil is checked from the instrument panel: With the car on a level surface and the ignition switch on to the first position, toggle through the controls to the proper read-out screen, turn the ignition to the second position, and wait for the car’s computer to check the oil level.
Most models built after 1990 use Mobil 1 Synthetic oil. Check your owner’s manual for grade and weight of the oil and note it on your glove-box information card. In colder climates, a different weight oil may be needed in winter from the one used in the warmer months. Note this as well.
Before adding oil, note the position of the filler cap. When you are through adding oil, make sure the cap is in the same position. That way you know it is properly seated. Never leave the oil cap off. To add oil, make a funnel out of a plastic bottle and keep it in a plastic bag.
Other vital fluids
The engine coolant in the radiator is checked by looking into the radiator on older cars or on newer cars by checking the level through the translucent sides in the remote plastic coolant reservoir. Checking coolant is best done when the engine is cold. Avoid opening the radiator or coolant reservoir when the engine is hot, but if you must, check the owner’s manual about how to do this without getting scalded. To add fluid, use a 50/50 mixture of antifreeze and water. Make sure your antifreeze is rated for your climate and seasonal temperature range.
The windshield washer reservoir has a plastic cap with a washer spray symbol on it. Always use the windshield washer fluid designed for this specific purpose. Never use dish detergent because it will eat your paint and may destroy the washer pump. Windshield washer fluid may be purchased at the super market or at any auto parts store. Windshield washer fluid comes in different colors depending on how much antifreeze it contains to keep from freezing in the winter. Check the label and your owner’s manual to make sure the windshield washer fluid you buy is appropriate for your climate.     
The brake fluid cylinder is attached above the master cylinder to the driver’s side of the engine on the firewall and is usually semitransparent. The maximum and minimum levels are stamped into the side of the reservoir. On newer cars, there is a float in the reservoir that triggers a switch when the fluid is too low, which engages the warning light on the dash board.
Do not add brake fluid unless the level is near or below the minimum level. The brake fluid reservoir cap is not pressurized. Use “DOT 4” non-silicone fluid available at auto parts stores. The container should be marked “330.1” or “330.0,” as approved by Mercedes-Benz. Check your brake fluid if the brakes feel spongy. If they do and the fluid is at the right level, do not drive the car. If you have any concerns at all, have the brake system checked by a qualified technician.
The power steering fluid reservoir on older cars is usually located to the lower driver’s side of the engine attached to the power steering pump, which is driven by a belt. The level can be checked visually or with the dipstick on the cap. Use transmission fluid or special fluid specified by Mercedes Benz as stated in your owner’s manual. Write the type of fluid on your information card. Note that on newer cars the power steering reservoir is not accessible and can be checked only by a service technician. Many of the latest models no longer use power steering fluid. Check your owner’s manual if you’re in doubt.
The automatic transmission fluid is the only fluid that has to be checked after driving some distance and with the engine running and the transmission in Park. Some of the newer models have no dipsticks and are not serviceable. On older models, remove the dipstick and wipe with a chamois or lint-free cloth before checking the level. Never use a paper towel as it will leave lint and contaminate the fluid. Add a small amount of fluid through a small funnel. On older cars this transmission fluid should be replaced every 30,000 miles; newer cars can go 40,000 to 60,000 miles between fluid changes.
Engine compartment inspection
After checking the fluids, check the various components in the engine compartment. Most repairs must be done by your mechanic. However, you can check the engine components for wear.
Be vigilant about fluid leaks. Look under your car often and check the garage floor or driveway for stains and puddles. Yellow/green fluid is coolant; pink or red is transmission or power steering fluid; brown is engine oil; and clear is usually air conditioner (a/c) condensation, which is normal. Learn where the air conditioner drains are so you can tell if the puddle is normal or if something else is leaking.
The engine air filter is in a canister and may be round or rectangular. Filters in some models cannot be removed easily. If possible, remove and shine a light through the filter to see if light is visible from the other side. If not, then the air filter is clogged and must be replaced with one from your dealer. Use only genuine Mercedes-Benz replacement air filters. If you aren’t comfortable replacing it yourself, ask your technician to do so next time your car is serviced. Be on the lookout for nuts, dog or cat food, as mice will bring these things in through the air ducts and store them in the air filter.
On some Mercedes-Benz engines, a single belt drives the water pump, power steering, alternator, and a/c compressor. If the belt should break, the red charging light will come on, the coolant temperature gauge will rise, and/or a warning light will come on, and the power steering will stop working, making it harder to turn the wheel at slow speeds. If this happens, avoid damage to the engine by stopping immediately and having your car towed to a service facility. On older cars there are multiple belts, one for each accessory. Check your belts often for cracks, worn areas or tears. If you see any sign of wear, don’t wait; take the car to your mechanic for replacement.
Check all hoses attached to your radiator and other engine components for softness, bulging, and leaks near the clamps. If any of these appear, have your mechanic replace them with genuine Mercedes-Benz parts.
Check your owner’s manual for the locations of the fuses, which may be in several locations in the car. Inside the fuse box, there may be spare fuses and a tool to extract the fuses. Make sure you know what a blown fuse looks like. Most fuses are color-coded to make sure you replace them with ones of the same amperage. If the replacement fuse blows, there may be an electrical short. Have your technician find the cause and fix it.
Make sure you know where the auxiliary battery hookup is in the engine compartment in the event that you need to have your car jump-started.
Once you’ve been through this drill with the help of these instructions and your owner’s manual, or had someone show you where everything is located, it will be easy for you to do it yourself. Just having the knowledge of where everything is and what it does is a significant contributor to your self-confidence around automobiles, and Mary guarantees that you’ll even be way ahead of most men in your knowledge of your car.
 

Under dash hood latch releases (inset details) and hood latches on representative classic and contemporary Mercedes-Benz automobiles – a 1969 280S and a 2015 C400.

RIGHT: Comparison of engine compartments, showing placement and inset details of maintenance access points
 
On older models, check belt for tension and hoses for softness, bulging, and leaks near clamps.
New cars have non-adjustable polybelts. The fuse box is located under the dash on this 1969 280S.
Modern vehicles may have multiple fuse boxes – this 2015 C400 has four. Check your owner’s manual for fuse box location.
Models built between 2000 and 2010 did not have oil dipsticks; oil is checked using the instrument panel information system.