Maintenance is key to a happy healthy car. When you neglect your girlfriend what do you do? You take her to get pampered, hair did, nails did, massage, or she’ll leave yo whack ass. Well same thing for your car if you don’t take care of it, it’s going to leave too! So take care of your car, and don’t neglect the little things. This is the first installment of my “Valve adjustment” series. where I will go through step by step how to do a valve adjustment on your motor. Not only will doing a valve adjustment be beneficial to your car, but it’s also a great way to work on your car without having to spend money (provided you have feeler gauges and the valve adjustment tool) and feel like a regular ol grease monkey.
This how to was an easy one since I didn’t actually have to do any work. I just took the pictures. Since Patrick was going to do a valve adjustment anyways I told him to come by my house and we could do a write-up on it. If you are interested in reading more about Patrick’s S2000 you can click here to see the write up we did on it and him a few weeks ago. >>>>>>>>>>>>>>>
Now onto the process of the valve adjustment. please note a few things
- Engine must be cool 100 degrees or below (at-least cool to touch)
- On the S2000 the heat shield is sort of in the way, you don’t need to remove it. Just work around it. but you can remove if you like, however make sure it goes back on!
- Patrick has an AP2 valve cover on his AP1. Some eagle-eyed readers might spot the difference. This won’t have any effect on the valve adjustment, and the procedure is the same as the only difference is the PCV.
- If its your cars first time having the valve cover removed, it would be a good idea to get a new valve cover gasket and valve cover grommets. ( don’t use autozone, pepboys, orileys, or any other non oem brand. they ALWAYS leak! )
- Be very careful when tightening the 10mm jam nuts when doing the adjustment. they can snap if over tightened, also be careful when tightening the 10mm nuts holding the valve cover on, these are very susceptible to breakage as well.
- DON’T FORGET TO REMOVE THE RATCHET OFF THE CRANK PULLEY BOLT!!!! If you don’t, when you go to start the car you will break something for sure and it will scare the shit out of you.
- We removed the air intake just for photo reasons, you should not have to although it may make it easier for you to turn the crank pulley.
removing the valve cover.
- remove spark-plug wire cover
- unplug TDC sensor 1 and 2 (you will have to unbolt/remove the TDC1 sensor only, you can leave the TDC2 sensor bolted in)(don’t lose the O ring or it will leak)
- this is what the TDC1 sensor looks like removed from the valve cover (sensor is sitting on the fuel rail)
- disconnect the coil packs and pull the coil harness over towards the header (you may need to disconnect the VTEC solenoid plug to get enough slack in the harness to move it out-of-the-way.)
- remove the coil packs
- remove the 5 bolts holding on the valve cover
- remove the dipstick
- disconnect the pcv hose
- disconnect the valve cover vent hose going to the air filter tubing
- Remove plastic fuel rail cover.
You should be left with this. As you can see below we have pulled everything off to the side of the head. Be cautious when taking off the valve cover its tight against the fire wall, the tall cam caps, spark plug tubes, and all the wires don’t make getting it off easy. But it is possible just stay calm and don’t get frustrated. DO NOT pry the valve cover with a screwdriver you will scar the head or valve cover mating surfaces not allowing a proper seal causing leaks once re installed. You can take a rubber mallet and gently tap the sides of the valve cover to break the initial seal. but keep in mind it really isn’t going to move too much since the spark plug tubes are metal and will not allow for it to move much. Usually you can just grab the valve cover with both hands on opposite corners and rock the valve cover loose without even gently taping it with a rubber mallet.
setting the motor to TDC (TOP DEAD CENTER) the correct order for adjusting the valves on an S2000 is cylinder #1, #3, #4, #2. To adjust the valves you must make sure each the cylinder number you are adjusting is at TDC. i.e. if you are adjusting the valves for cylinder #1, then cylinder #1 must be TDC. When you move on to cylinder #3 you must make sure Cylinder #3 is set to TDC, then on to cylinder #4, and finally ending at cylinder #2.
I remove all the spark plugs, this will allow the engine to turn over easier by not holding compression since the spark plugs are out. ( this is not necessary but it does make it a bit easier) The crank pulley at the front of the motor (nearest the radiator) takes a 19mm socket and from there you are going to manual spin the engine to TDC
There is also the air control vacuum reservoir that is somewhat in the way of accessing the crank pulley bolt. this just unbolt’s (one 10mm bolt) and you can move it out-of-the-way
There are marks on the cam gears that indicate TDC
you can also see here where I’m pointing to them with the pointer finger. (I know it’s hard to see on the pictures what I’m talking about but that’s why I put in the factory manual above as reference)
another sure-fire way to know that you are making sure each cylinder is TDC is to take note of the cam lobes for each cylinder. remember that cylinder #1 is the one closest to the cam gears and cylinder #4 is closest the firewall
seen below cylinder #1 TDC exhaust cam “VTEC” lobe is at 11 o’clock and the intake cam “VTEC” lobe is at 2 o’clock (don’t worry about the pointer finger, it’s not pointing to the cam lobes)
Cylinder #3 TDC exhaust cam “VTEC” lobe is at 11 o’clock and the intake cam “VTEC” lobe is at 2 o’clock
Cylinder #4 TDC exhaust cam “VTEC” lobe is at 11 o’clock and the intake cam “VTEC” lobe is at 2 o’clock
Cylinder #2 TDC exhaust cam “VTEC” lobe is at 11 o’clock and the intake cam “VTEC” lobe is at 2 o’clock
the reason the cam lobes must be at 11 and 2 o’clock is this allows there to be no pressure from the cam lobe on the rocker arms so you can adjust the valves without any tension on them. If you line up the timing marks for each cylinder per the manual above the cam lobes will all line up 11 and 2 o’clock for the respected cylinder you are working on. Finally if you grab the rocker arms they should have some play in them when each respective cylinder is TDC this is normal, don’t freak out. Even after you’re done adjusting the valves there will be some movement and that’s ok. If there is no movement and its at TDC for that cylinder then you have a problem.
adjusting the valves: now remember that you are going to have to adjust one cylinder at a time, making sure each cylinder you are adjusting is at TDC.
you are going to need a 10mm 7-1/2-Inch Jam Nut Valve Adjustment Tool, and bent feeler gauges. Straight ones will not work, they will not allow you to feel the proper drag on the feeler gauge when in-between the rocker and cam. (some people say that you can use a 10mm wrench and flat head screwdriver… but that’s really difficult just order the jam nut valve adjustment tool. Just search google for Honda valve adjustment tool.)
Obviously the f20/f22c is a 16 valve engine. There are 4 valves per cylinder times four cylinders equalling 16. So that means each cylinder will have 2 exhaust valves and 2 intake valves. You will have to individually adjust each one. There are many theories out there about how tight or lose to run your valves I tend to run them on the tighter side of the specs. This allows for the stem of the valve to be pushed in a teeny tiny microscopic bit more, which will allow for more air and fuel to get drawn in. But be careful as if the valves are too tight it could cause the check engine light to come on, scar the valve terrain/cams, or even at worst case piston to valve contact.
Usually on Honda’s the valve clearances are noted on the hood (a white sticker on the underside of the hood) how ever take note if there has been a motor swap installed on the car the hood reference will not be correct. You can always check the internet for the specs for your particular motor. for the F20C its
this is also noted on the factory manual pictures in the beginning of this article.
Now the you have got which ever cylinder you are working on at TDC you are ready to adjust the valves. you are going to take your jam nut wrench and place it on the rocker assembly like the picture below. (below is on cylinder #1 intake side.)
the 10mm nut is just a lock to keep the valve clearance set. the flat head part is used to adjust screw which in turn adjusts the gap between the rocker and the cam. You will need to break loose the 10mm before you can adjust the gap with the flat head.
Below you can see where you are going to slide the feeler gauge into. (note it doesn’t matter what cylinder I’m on as I’m just showing you where the feeler gauge goes in.)
as you can see above I have the feeler gage stuck in from the center of the head sliding it between the cam and rocker. You will not be adjusting the gap on the VTEC lobe. Just the smaller lobes on each side of the VTEC lobe. Remember its two valves for exhaust and two for intake, that means two adjustments on the exhaust lobes, and two adjustments on the intake lobes per cylinder. You are going to slide the feeler gauge back and forth while you are turning the flat head (small quarter turns, as it only takes a little to adjust the gap) adjusting the gap between the cam and the rocker. You want the feeler gauge to have some resistance when sliding it back and forth. If you can’t insert the feeler gauge then the valve clearance is too tight, if the feeler gauge goes in easily then the valve clearance is too loose. You need to find the in-between too tight and too loose. ( make sure you’re using the correct size feeler gauge, as the sizes will be different between exhaust and intake sides.) don’t mix them up. **** PLEASE NOTE***** the manual states to put the feeler gauge in-between the valve adjusting screw and the valve stem. either way works fine, we just choose to do it this way. ******
you can see above how one hand is turning the flat head part, and the other is moving the feeler gauge in and out. Once you are satisfied with the clearance you are going to now have to hold the flat head perfectly still (not allowing it to rotate clockwise or counter-clockwise) as you lock the 10mm nut back down. DON’T MAKE IT TOO TIGHT IT WILL SNAP OFF it only needs to be 14 lb/ft. Once tightened re check the clearance to make sure you didn’t make it tighter as you tightened the 10mm jam nut. Your first couple of valves will be challenge as you will be getting the feel for it, but after you’ve done 2 cylinders (that’s 8 valves) you should start to understand what you’re doing.
here is a couple more shots of what it looks like using one had to slide the feeler gauge, and the other to adjust the gap with the flat head.
Remember you can only do one cylinder at a time, because only one cylinder is at TDC at a time. so that’s ( yes I know that it is possible to do more than one cylinder at a time, but just to keep things simple and less confusing we are doing it this way)
- 4 valves (2 for intake, 2 for exhaust) on cylinder #1 at TDC
- 4 valves (2 for intake, 2 for exhaust) on cylinder #3 at TDC
- 4 valves (2 for intake, 2 for exhaust) on cylinder #4 at TDC
- 4 valves (2 for intake, 2 for exhaust) on cylinder #2 at TDC
I know that this seems like a lot of information to read especially since I’m not the best at explaining but as soon as you get your valve cover of it will all start making sense.
Once you have adjusted all 16 valves, 4 per cylinder, while each respected cylinder is at TDC. I go through and double-check each 10mm jam nut (you can check this without having to make each cylinder TDC) to make sure they are tightened (remember these only need to be 14 lb/ft), use flat head to hold the adjustment screw in the correct position so you don’t mess up the clearances that you have just set. Now set each cylinder to TDC and make sure the valve clearances are still what you set them to.
- wipe away oil and debris from the head where the valve cover will sit to make sure the seal is good, wipe away oil and debris off the valve cover gasket as well.
- put valve cover back on
- tighten valve cover bolts
- reinstall spark plugs
- reinstall coil packs
- reattach coil plug harness to each coil
- reinstall the TDC1 sensor and reconnect the TDC1 and TDC2 plugs
- reinstall dipstick
- reinstall pcv
- reinstall valve cover vent hose to air intake
- reattach the air control vacuum reservoir near the crank pulley
- reinstall coil pack cover
- reinstall the fuel rail cover
- wipe away any oil that has leaked out when the valve cover was removed (usually some will leak out on the back of the head and on to the transmission, then onto the floor. this is normal if it does leak just make sure you check your oil level on a flat surface, and refill if necessary)
- double-check to make sure you have removed all tools out of the engine bay, and that every electrical connector is plugged back in.
And lastly remember to remove the ratchet from the crank pulley before you start the car
They say to wait 30 min before starting the car to allow a proper seal to form between the head and the valve cover gasket, but I never do this. If you start the car and the CEL is on down worry you probably just forgot to re connect a plug on a sensor
you should be left with something like this (note Patrick is not running a coil pack cover)