1. Gather Your Supplies:
* New oil: Consult your owner's manual for the correct type and quantity (usually 4-5 quarts of 5W-30).
* New oil filter: Again, check your owner's manual for the correct filter type. Auto parts stores can help you find the right one based on your vehicle's VIN or engine type (likely a 3.8L V6).
* Oil filter wrench: Choose one that fits your oil filter. A cap-type wrench or strap wrench often works best.
* Wrench for the drain plug: This is usually a 15mm socket or wrench.
* Drain pan: A large enough container to hold at least 5 quarts of oil.
* Funnel: To avoid spills when adding new oil.
* Jack and jack stands (or ramps): Essential for safe and easy access to the drain plug. Never work under a car supported only by a jack.
* Gloves: To protect your hands from dirty oil.
* Rags or shop towels: To clean up spills.
* Torque wrench (optional but recommended): To tighten the drain plug to the correct specification (check your owner's manual).
2. Prepare the Vehicle:
* Warm up the engine: Run the engine for 5-10 minutes to warm the oil, making it flow more easily. Don't let it get too hot, though.
* Secure the vehicle: Use a jack and jack stands to lift the front of the car. Ensure it's securely supported before proceeding. Alternatively, use ramps.
* Locate the oil drain plug and filter: The drain plug is located on the oil pan, usually towards the bottom of the engine. The oil filter is typically on the side of the engine block.
3. Drain the Old Oil:
* Position the drain pan: Place the drain pan under the oil drain plug.
* Remove the drain plug: Carefully loosen and remove the drain plug with your wrench. Be prepared for hot oil to flow out. Let it drain completely (this may take 15-20 minutes).
* Replace the drain plug: Once the oil has drained, carefully reinstall the drain plug and tighten it securely (but don't overtighten). If using a torque wrench, consult your owner's manual for the correct torque specification.
4. Change the Oil Filter:
* Loosen the old filter: Use the oil filter wrench to loosen and remove the old oil filter. Some oil will likely spill, so have rags ready.
* Lubricate the new filter's gasket: Lightly lubricate the rubber gasket on the new oil filter with fresh oil.
* Install the new filter: Screw the new filter on by hand until it's snug. Then tighten it according to the instructions on the filter (usually about ¾ to 1 full turn after the gasket contacts the engine).
5. Add New Oil:
* Locate the oil fill cap: This is usually on top of the engine; it may be marked with an oil can symbol.
* Remove the oil fill cap: Remove the cap and insert the funnel.
* Add new oil: Slowly add the correct amount of new oil as specified in your owner's manual. It's better to slightly underfill than overfill.
* Replace the oil fill cap: Securely replace the oil fill cap.
6. Check the Oil Level:
* Start the engine: Run the engine for a minute or two.
* Turn off the engine and wait a few minutes: This allows the oil to settle.
* Check the oil level: Use the dipstick to check the oil level. Add more oil if necessary until it reaches the "full" mark.
7. Clean Up:
* Dispose of the old oil properly: Take the old oil to a recycling center or auto parts store that accepts used oil.
* Clean up any spills: Wipe up any spilled oil with rags.
8. Lower the Vehicle: Carefully lower the vehicle using the jack.
Important Notes:
* Always consult your owner's manual: This guide provides general information; your owner's manual contains specific instructions for your 1999 Buick LeSabre.
* Safety First: Never work under a car supported only by a jack. Use jack stands for safety.
* Dispose of used oil responsibly: Improper disposal of used oil harms the environment.
If you're uncomfortable performing this task yourself, it's always best to take your vehicle to a qualified mechanic. This is just a guide, and individual steps may vary slightly depending on your specific vehicle.
