Valve Clearance Adjustment

This DIY outlines the procedure of adjusting the clearances betwean the intake and exhaust valves and their respective lifters. This procedure should be performed if you notice that the engine sounds different than it used to.

I reccomend reading this article: Maintenance – Valve Adjustment to familiarize yourself with the basic procedure.

- Torque Wrench (required)
- Small Flat Head Screwdriver (required)
- 10mm Socket (required)
- Short Extention (required)
- Feeler Guage (required)
- Long Extention (required)
- 19mm Socket (required)
- Spark Plug Socket (optional)
- Gasket Sealer (optional)

First off, you need to get your car ready… This procedure should only be done when the car’s engine is cooled down. You should leave the car in a garage overnight to let the engine cool down completely. Make sure that you will have enough time to complete this procedure the following day. With food and drink breaks and a little rest here and there it will take a full day (not night) to complete. Especially if you’re not too familiar with your engine bay.

Please download the following file: ValveAdjustment.pdf (1.0MB) and look it over. This file contains information about adjusting valve clearances taken from Honda’s service manual.

Page 9 of that document contains the instructions.
Page 10 shows you the pulley and how to read it at TDC.
Page 11 shows you the valve cover tightening sequence.
Page 17 shows you the clearances and how to adjust them.

You should first start by removing the negative battery terminal. I wrapped the connection up with some masking tape to prevent any accidental contact. I then removed the positive battery terminal and did to it what I did to the negative.

Here you see a picture of the ignition coils. The wire cover is right above them.

To take off the wire cover, first use a large screwdriver to turn the two plastic “screws” 90 degrees, then pull up on it. Use a 10mm socket and socket wrench to take off the little bolts that hold the ignition coils down. It is easier to pull the coils out a little before taking off the connectors.

Using the same 10mm socket and socket wrench take off the bolts that hold down the throttle cable clamps. Tie off the whole assembly so that it doesn’t get in your way. I tied mine to my strut bar with some masking tape.

I measured the voltage on the exposed bolt in this picture with a multimeter and it indicated that there was still 0.15V of potential difference betwean it and ground. I waited about 15 minutes before the voltage totally dissipated. I guess that the alternator acts like a capacitor?

Anyway, it’s best to wait 15 minutes from the time you disconnect the battery before beginning on this step of the procedure. After that time has elapsed simply move the rubber boots aside and take out the connector and unbolt the other connection. You’ll need the 10mm socket and socket wrench again.

Remove the two bolts holding the wire harness to the valve cover by using a 10mm socket and socket wrench. Then thread the end of the wire harness (by the alternator) through and arrange the whole thing to the side as in the picture (highlighted orange).

Remove the bolt that held the bracket that held the wire harness (circled in green) by using a 10mm socket and socket wrench. Remove the bolt that holds the aluminum hardline (circled in red). Removing both of these will make it easier to take off the valve cover.

Slip the wire harness off of the two studs on the valve cover (circled in blue). Grasp the clip on the hose that attaches from the filter box to the valve cover and push it back towards the filter box. Take the rubber hose off of the valve cover. You can use a screwdriver to get under the rubber hose to help pry it off.

Take the support bracket off of that one rubber hose that leads into the aluminum hardline and rotate it out of the way. This will make taking off the valve cover a little easier since the rubber hose and the aluminum hardline will be able to flex a little.

Loosen the valve cover bolts (circled in purple) with a 10mm socket and socket wrench. Pull on the bolts to make sure that they are loose; you should be able to move them in and out. Remove the valve cover by prying up on it. The rubber hose that leads into the aluminum hardline will get in the way, but you should be able to push it aside.

The intake lifter adjustment screws and nuts are circled in green. The exhaust lifter adjustment screws and nuts are circled in red. The feeler guage should be set to .007 inches for the intake side and .009 inches for the exhaust side (as in the file provided on Page 17). You can also take out the spark plugs using a spark plug socket, long extention, and socket wrench to fascilitate turning of the engine by hand.

You may take off the pulley cover to better see what happens when you crank the engine by hand. First disconnect that little connector that goes into the cover. Take out the rubber boot and pull on the connector. Then take out three bolts that hold the pulley cover down. You will need to use a 10mm socket and a socket wrench to take them out.

Notice the spoke on the pulley marked “UP”. Also notice the two “ears” on the pulley that are also facing upwards. If you can not read the word “UP” engraved into the spoke of the pulley, then you can use these two “ears” as your guide. With this spoke in the position shown in the picture, one set of pistons is at TDC (Top Dead Center).

Jack up the driver’s side and take off the wheel. You will then have access to the crank shaft via a hole in the wheel well. Mate a socket wrench with a long extention and a 19mm socket and put it through the hole in the wheel well; feel around for the crank-shaft bolt. Once you find it, you will be able to turn the crank-shaft by turning the socket wrench counter clock-wise. Watch what happens to the valves and the pulley as you do so.

Now you’re ready to adjust the valve clearance. You can start with the exhaust side since there’s a lot of room for the feeler guage; that will make things easier. Turn the engine by hand until a set of lifters that you have your eyes on pops up; then turn the engine a little more to make sure that the lifters will stay in that position. They will stay in the same position throughout most of one revolution of the crank-shaft because of the shape of the cam shaft.

When one set of lifters is in the right position (as described above), loosen the valve adjuster lock nut and loosen the adjusting screw. Put the feeler guage betwean the valve stem and rocker arm (as shown in the attached document on Page 17) and tighten the adjusting screw until it “grabs” the feeler guage. Tighten down the valve adjuster lock nut to 14 foot pounds in an EX and HX and 13 foot pounds in a DX and LX.

Repeat the above process for all exhaust valves. Then move on to the intake valves. Remember to use the appropriate clearances for the exhaust valves and the intake valves (as outlined on Page 17 of the attached document). When you finish adjusting all of the clearances simply put everything back together. It’s also a good idea to dab a little gasket sealer onto the head where the valve cover gasket makes sharp bends; this will keep the gasket from leaking until it settles.

Grey from civicforums

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