How to Tune Up a Grand Cherokeeby Jeanene S. Valentine
Every vehicle on the road requires basic routine maintenance to help keep it in excellent running condition. Most mechanics will recommend a tune up every 30,000 miles or 24 months, whichever comes first. Saving a penny wherever you can is always welcome. Learning to do a tune-up on your Jeep Grand Cherokee is the perfect way to start performing routine maintenance yourself. Not only are you learning a new skill, but you are saving yourself both time and money.
Raise and support the vehicle front hood with the supporting rod. Visually inspect the engine belts, checking for cracks and frays. Also inspect the vehicle fluids such as the engine coolant, brake fluid, power steering fluid (if applicable), transmission fluid and windshield washer fluid. Inspect the vehicle tires and check tire air pressure with an air-pressure gauge. Replace belts and fluids as needed and bring the tires up to proper air pressure if necessary.
Using a wrench, remove first the negative (black) battery cable from the battery, then repeat with the positive (red) battery cable. Inspect cables for frays and debris. Brush and clean both the battery cable terminals and battery cable posts using the wire brush. If battery acid corrosion will not come off, pouring a little Coca-Cola on it will loosen it.
Place the engine oil container beneath the vehicle, then crawl under the vehicle. Locate the engine oil drain plug at the bottom of the oil pan. Place the container below the drain plug, slightly forward to catch the oil that will drain out at first. Using the ratchet wrench and correct socket, quickly remove the oil drain plug and allow all the engine oil to empty into the container, then replace the plug. Remove the oil filter using the oil filter wrench and replace it with a new oil filter. Push the filled oil container from beneath vehicle and then crawl out yourself. Open the engine oil fill cap, place the fluid funnel inside the exposed hole and pour 4 qt. of oil inside. Replace the engine oil fill cap. Check the engine oil and add more if needed after you have completed the tune-up.
Using a flat-head screwdriver, pop off and remove the clips surrounding the air filter plate. Lift the top of the air filter plate and set it aside. Lift and remove the old air filter and wipe the inside of the air filter housing clean, using a shop towel. Place the new air filter into the housing and make sure it fits properly. Replace the air filter plate and snap the clips back into place.
Remove the spark plug wires from the tops of the spark plugs. Pull from the boot at the end of the wire, not from the wire itself. Make sure to label or mark each wire so they will not get mixed up. Using the spark plug wrench, remove each spark plug by turning counterclockwise. Carefully replace the new spark plugs into the sockets. Turn lightly by hand clockwise to ensure the spark plug is being properly threaded into the cylinder. Use the spark plug wrench to finish tightening the spark plugs.
Loosen the distributor cap mounting screws (they are mounted and do not come out), using a screwdriver. Pull the distributor cap up, leaving the spark plug wires attached, and set it slightly off to the side after a visual inspection. Visually inspect the inside of the distributor by checking for cracks and corrosion on the rotor. Remove the spark plug wires, one at a time, by pulling them straight off. Be sure not to mix up the wires and replace them in the exact same order. Now you can replace the other end to the corresponding spark plug. Reattach the distributor cap and tighten the screws with a screwdriver.
Reattach and tighten the negative (black) battery cable to its correct post with a wrench, then the positive (red) cable. Lower and properly close the vehicle hood.
- When purchasing the spark plugs, make sure they are auto-gapping plugs. Spark plugs need to be at a specific gap gauge. Purchasing this type of plug does all the work for you. You can also purchase spark plug lubricant, which ensures your new spark plugs will not freeze inside the cylinders and that you will be able to replace them easily.
- Allow at least 30 minutes for the vehicle engine to completely cool before beginning any engine work.
Items you will need
- Ratchet wrench with sockets
- Flat-head screwdriver
- Phillips screwdriver
- Distributor cap and wires
- Engine oil (at least 5 qts.)
- Oil filter
- Oil filter wrench
- Engine oil tub or recycling container
- Air filter
- Spark plugs (one for each cylinder)
- Spark plug wrench
- Wire brush
- Tire air-pressure gauge
- Clean shop towels