1998 Accord Valve Adjustment (4 cylinder, VTEC specific)
Be careful during this procedure. Work on the engine only when it is completely cool. Do not get oil on the timing belt or other belts.
Valve clearances for the 1998 Honda Accord VTEC 4 cylinder engine:
Intake (closest to cabin): 0.24mm to 0.28mm
Exhaust (closest to front of car): 0.28mm to 0.32mm
Tools required to adjust valves:
- Feeler gauges
- 19mm socket
- 10mm socket
- socket wrench
- 10mm box/open wrench
- standard screwdriver
- medium pliers
- various socket extensions (I used 12" and 3")
- universal (swivel) socket extension (optional, but makes life easier)
- Turn the front wheels all the way to the left.
- Remove all plug wires from the plugs and move them out of the way of the valve cover.
- Disconnect the 2 hoses from the valve cover and move out of the way of the cover (pliers can be used to loosen clamps).
- Loosen the five 10mm bolts until they are loose in the cover. They do not have to be fully removed from the cover - they are very long, but only threaded a little ways.
- Once all the bolts are loose, the valve cover can be pulled off. Slowly pull it off, helping any areas where the valve cover gasket is sticking.
- With the cover off, wipe off any oil residue from the inside of the valve cover.
- Remove the dipstick and tube by removing the single 10mm bolt.
- Pull the wiring harness from the timing belt upper cover (it's just tucked in there).
- Remove the timing belt upper cover by removing the two 10mm bolts from it. You will likely need a swivel (universal) joint to get at them. The timing belt should now be visible, as well as the head. Check your timing belt while you're in there and make sure it looks good (no cracks). Also, inspect the drive belts while you are inspecting that area anyway.
- In the wheel well, you'll see a small opening. Insert the 19mm socket on an extension through that hole and connect with the crankshaft bolt behind it.
- Crank the bolt counter clockwise until the arrow on the timing sprocket (at top of timing belt) has the word "UP" facing upwards and in the full upright position.
- At this point the number 1 cylinder valves (intake AND exhaust) can be adjusted (cylinder 1 will be at Top Dead Center). This is the cylinder closest to the sprocket. You'll notice a "1" on the head, right near that sprocket.
- Check the valve clearances with the correct feeler gauges. The gauge should drag along between the valve and its associated lifter. If it doesn't fit or if it easily fits and slides around without any drag, adjustment is required. Do not apply pressure on the top of the valves at all, because it screws up the measurement. The place to check is right above the valve. Wiggle the arm above the valve a little and you'll see which parts don't move. Test with the feeler gauges right above that!
- If adjustments are required, take the 10mm box wrench and loosen the nut on the top of the valve. Adjust the clearance then by adjusting the standard screw. It doesn't take much, so don't move it too far. When the adjustment is complete, hold the screw in place and tighten the nut. Re-check with the feeler gauge to ensure your adjustment is correct.
- When the first cylinder is complete, turn the crankshaft 90 degrees counterclockwise. The "UP" should now be facing the front of the car. Adjust the valves for cylinder 3 (note, from front of car, cylinders look like 4-3-2-1).
- When cylinder 3 is complete, turn the crankshaft 90 degrees counterclockwise again. "UP" should be at the bottom of the sprocket. Adjust the valves for cylinder 4.
- When cylinder 4 is complete, turn the crankshaft 90 degrees counterclockwise again. "UP" should be facing the passenger compartment. Adjust the valves for cylinder 2.
- Re-assemble car (reverse of first 9 steps). Remove all tools from the engine bay. Replace the valve cover gasket only if leaking or broken. The rubber gaskets on Honda valve covers are reuseable.
- Start the engine and listen for