Tools and Materials Needed:
- Replacement valve cover gasket
- Socket wrench set
- Screwdriver
- Pliers
- Gasket scraper or putty knife
- Clean rags or paper towels
- Engine degreaser (optional)
- RTV silicone sealant (optional, for certain gaskets)
Procedure:
1. Preparation:
- Allow your engine to cool down completely before starting the repair.
- Locate the valve cover on the top of the engine. There may be a decorative engine cover that needs to be removed first.
2. Remove Engine Cover (if equipped):
- Disconnect any vacuum lines or electrical connectors attached to the cover.
- Remove any bolts, nuts, or clips holding the engine cover in place.
- Set the engine cover aside carefully to avoid damage.
3. Clean the Area:
- Use the degreaser (if available) or a clean rag to remove any dirt, oil, or debris from around the valve cover.
- Ensure the area is dry and clean for a proper seal.
4. Remove Valve Cover Bolts and Unscrew Spark Plug Wires:
- Loosen the bolts holding the valve cover in place, but don't remove them completely yet.
- Remove the spark plug wires (or coil-on-plug connectors) from the spark plugs to make room for removing the valve cover.
5. Remove the Old Gasket:
- Carefully pry the valve cover from the engine block, starting at one end and working your way around. Use the screwdriver and pliers as needed.
- Once the valve cover is removed, lift it up and separate the old gasket from the valve cover and engine block surfaces.
6. Clean the Surfaces:
- Use the scraper or putty knife to remove any old gasket material from the valve cover and the engine block surfaces.
- Make sure the surfaces are clean, smooth, and free from any debris or old gasket residue.
7. Apply RTV Sealant (if needed):
- Certain valve cover gaskets may require the application of RTV silicone sealant to ensure a proper seal. Follow the instructions provided with your specific gasket.
8. Install the New Gasket:
- Place the new valve cover gasket in position on the engine block. Make sure it is seated properly and aligns with the bolt holes.
9. Reinstall the Valve Cover:
- Gently place the valve cover back on the engine block, ensuring the gasket remains in place.
- Insert and tighten the valve cover bolts gradually in a criss-cross pattern to avoid warping the cover.
- Reconnect the spark plug wires or coil-on-plug connectors.
10. Reattach the Engine Cover:
- If your vehicle has an engine cover, reattach it by securing the bolts, nuts, or clips.
- Reconnect any vacuum lines or electrical connectors that you disconnected earlier.
11. Check for Leaks:
- Start the engine and let it run for a few minutes.
- Check for any oil leaks around the valve cover area. If you notice any leaks, retighten the bolts as needed.
12. Cleanup:
- Clean up any spilled oil or degreaser from the engine bay.
- Dispose of the old gasket and other waste properly.
Tips:
- Check the condition of the spark plug wires or coil-on-plug connectors while you have them disconnected. Replace them if they appear damaged or worn.
- If the valve cover has PCV or breather hoses attached to it, ensure you connect them properly when reinstalling the valve cover.
- Replace any worn or damaged valve cover bolts or nuts.
- If you're not confident about working on your car's engine, consider having the valve cover gasket replacement done by a qualified mechanic or automotive technician.
Remember to follow the specific repair manual for your 1999 Nissan Quest for detailed instructions and any additional information related to your vehicle's model and year.
