- The first step to fixing a burnt valve is to remove the cylinder head. This sounds straightforward, but it can be time-consuming and requires some specialized tools. Begin by removing any components covering the cylinder head, such as spark plugs, cooling hoses, and wire systems.
- Next, loosen the cylinder head bolts in a specific order. This order matters because loosening one before another can cause warping of the head. You may need to use a breaker bar for this, as these bolts are tight. Then you can remove the cylinder head and take it to a workbench.
Step 2: Inspect the Valves
- Now you can inspect the valves, using a flashlight and a pick. Inspect the valve seats and valve faces. Worn-out valve seats can be repaired by grinding and machining. This requires specialized equipment and may be best done by a professional machine shop.
Step 3: Replace Damaged Valves
- If any valves are bent, cracked, or damaged, they must be replaced. This includes valve springs, keepers, and any associated hardware. Use caution when removing the valve guide, as it is often a press-fit and may require a specialized tool to remove.
- Once the burnt valve is replaced, you can reassemble the head. Be sure to properly torque all the bolts and replace the associated gaskets.
Step 4: Reinstall the Cylinder Head
- Double-check that the valves and seats are clean, reinsert the cylinder head into the engine block, and reinstall the head bolts. Hand-tighten the head bolts first, and then use a torque wrench to tighten the bolts in the proper sequence and to the specified torque settings.
- Make sure all fluids and electrical connections are correctly restored before starting the engine.
Step 5: Start the Engine and Test
- Start the engine, let it warm up, and let it run for a few minutes. Check for proper sealing and observe for any leaks or strange noises.
Remember that this is a complicated process that should only be undertaken by someone who has experience working with engines. If you are not confident, it's best to take your vehicle to a professional.
