How to Change the Oil on Your Buick Century

Getting Started With Your Oil Change

Changing the oil on your Buick Century is a task you can do at home with basic tools and materials. This guide walks you through the steps so you understand the process. Regular oil changes are one of the most important maintenance tasks you can perform to keep your engine running smoothly and extend the life of your vehicle.

Before you begin, gather what you need. Having everything ready before you start makes the job go more smoothly and keeps you from having to stop midway through:

• New oil (check your owner's manual for the correct type and amount)
• A new oil filter
• An oil drain pan
• A wrench or socket set
• An oil filter wrench
• Jack and jack stands (if you need to raise the vehicle)
• Rags or paper towels
• A flashlight or work light
• Newspaper or cardboard to protect your driveway

Wearing old clothes or an apron is also a good idea, as oil can stain. Work gloves will protect your hands from dirt and minor cuts.

Preparing Your Vehicle

Park your Buick Century on a flat, level surface. If you need more room to work underneath, you can raise the front of the vehicle with a jack, but always use jack stands for safety—never work under a vehicle supported only by a jack. Place the jack stands on solid frame points, not on plastic trim or thin metal panels.

Let the engine cool for a few minutes if you've been driving. Warm oil drains better than cold oil, but hot oil can burn you. A good rule of thumb is to wait about five to ten minutes after turning off the engine. You want the oil warm enough to flow easily, but cool enough that you can touch the engine block without pain.

If your driveway or garage floor is clean and you want to keep it that way, lay down newspaper or cardboard under your work area. This catches any spills and makes cleanup much easier.

Draining the Old Oil

Locate the oil drain plug underneath your engine. It's usually a bolt that sticks down from the bottom of the oil pan. Place the drain pan directly beneath it to catch the old oil. Using your wrench, turn the drain plug counterclockwise to loosen it. Once it's loose enough, carefully unscrew it by hand and let the old oil drain completely into the pan. This may take several minutes, so be patient. The oil will drain faster at first and then slow down as the pan empties.

Wipe the drain plug clean with a rag and set it aside. If your Century uses a crush washer under the plug—a thin metal ring that helps seal the connection—you may want to replace it with a new one. Over time, crush washers become flattened and don't seal as well. A new washer costs very little and helps prevent oil leaks.

Changing the Oil Filter

Find the oil filter on your engine. On most Buick Centuries, it's mounted to the side of the engine block. Use an oil filter wrench to turn it counterclockwise until it comes free. Carefully remove the old filter and let any remaining oil drain into your pan. Be prepared for a small amount of oil to spill—this is normal.

Before installing the new filter, apply a thin layer of new oil to the rubber gasket on top of the filter. This helps create a good seal and makes it easier to remove the filter next time. Screw the new filter on by hand until the gasket touches the engine, then turn it an additional three-quarter turn. Don't use the wrench to tighten it—hand-tight is the correct amount of pressure. Over-tightening can damage the gasket and make the filter hard to remove later.

Adding Fresh Oil

Reinstall the drain plug and tighten it securely with your wrench. Don't over-tighten, as this can strip the threads and cause leaks. Snug it down firmly, but stop once you feel resistance—you don't need to use all your strength.

Open the hood and locate the oil filler cap on top of the engine. It usually has an oil can symbol on it. Remove it and set it aside in a clean spot where you won't lose it. Pour the recommended amount of new oil into the opening. Check your owner's manual for the exact quantity your Century needs. Most Buick Centuries take between four and six quarts, depending on the model year and engine size.

Replace the oil filler cap and close the hood. Make sure the cap is tight so it doesn't come loose while you're driving.

Checking Your Work

Start the engine and let it run for a minute or two. This circulates the new oil through the engine and helps the new filter fill with oil. You may notice the oil pressure light on your dashboard—this is normal and should go out within a few seconds as the oil circulates. Turn off the engine and wait a few minutes for the oil to settle back into the pan.

Pull out the dipstick, wipe it clean with a rag, reinsert it fully until it seats, then pull it out again to check the oil level. The level should be between the minimum and maximum marks on the stick. If it's low, add a small amount of oil and check again. If it's overfilled, you can remove a small amount with a turkey baster or similar tool.

Dispose of your old oil properly. Many auto parts stores and service stations accept used oil for recycling at no charge. Never pour used oil down a drain or into the ground, as it's harmful to the environment.

When to Change Your Oil

Check your owner's manual for the recommended oil change interval for your specific model year. Many Buick Centuries benefit from an oil change every 3,000 to 5,000 miles, though this varies depending on your driving habits and the type of oil you use. Synthetic oils often last longer than conventional oils, so if you switch to synthetic, you may be able to go longer between changes.

Keep track of your oil changes by writing down the date and mileage in your owner's manual or a maintenance log. This helps you remember when your next change is due and shows future owners that you've maintained the vehicle properly.

Key Takeaways

• Gather all tools and materials before you start to make the job smoother
• Always use jack stands if you raise your vehicle—never work under a car supported only by a jack
• Warm oil drains better than cold oil, but let it cool enough that you won't burn yourself
• Replace the crush washer on the drain plug if it's worn or damaged
• Apply a thin layer of new oil to the filter gasket before installing the new filter
• Hand-tighten the new filter—don't use a wrench to tighten it
• Check your oil level after the engine has run and the oil has settled
• Dispose of old oil at an auto parts store or service station, never down a drain
• Refer to your owner's manual for the correct oil type, amount, and change interval for your Century

Frequently Asked Questions

How often should I change the oil in my Buick Century?

The recommended interval depends on your model year and driving conditions. Most Buick Centuries should have an oil change every 3,000 to 5,000 miles. Check your owner's manual for the specific recommendation for your vehicle. If you drive mostly in stop-and-go city traffic or tow a trailer, you may need to change your oil more often. Synthetic oils often last longer than conventional oils, so if you use synthetic, you may be able to extend the interval.

What type of oil does my Buick Century need?

The correct oil type and viscosity for your Century depends on the model year and engine size. Your owner's manual will specify whether you need 5W-30, 10W-30, or another grade. Using the wrong oil can affect engine performance and fuel economy. If you don't have your manual, you can also find this information on the oil filler cap under the hood or by contacting a Buick dealer. When you go to an auto parts store, the staff can help you find the right oil once you tell them your vehicle's year, make, and model.

Can I change my oil if my engine is completely cold?

While you can change your oil when the engine is cold, warm oil drains much faster and more completely. Cold oil is thick and flows slowly, so draining takes longer. The ideal approach is to run the engine for a minute or two to warm it up, then turn it off and wait five to ten minutes before starting your oil change. This gives you the benefit of warm, flowing oil without the risk of burning yourself on a hot engine.

What should I do if I spill oil on my driveway?

If you spill a small amount of oil, you can clean it up with absorbent materials like kitty litter, sand, or oil absorbent pads. Sprinkle the material over the spill, let it sit for several minutes to soak up the oil, then sweep it up and dispose of it properly. For larger spills, you may need to use a degreaser or contact a professional cleaning service. To prevent spills in the future, lay down newspaper or cardboard before you start working, and keep your drain pan directly under the drain plug.