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DIY Valve lash adjustment

134K views 149 replies 93 participants last post by  2000hondacvcdx 
#1 · (Edited)
Valve lash DIY

I am not responsible for any damage you cause to the engine or yourself during this procedure.

Alright, after seeing enough threads on here about adjusting the valve lash, ive decided to go ahead and make a diy thread for it.

Here are the tools that will be needed:

1.)10mm wrench
2.)Flathead screwdriver
3.)10mm socket (not needed, but recommended to speed up process of valve cover removal)
4.)17mm deep socket
5.)Large sized ratchet to bar engine over
6.)Feeler gauges that include .007” and .009”
7.)Phillips screwdriver
8.)Spark plug deep socket remover and extension
9.)Piece of durable wire, a straw, chop sticks, coat hanger (with no sharp edges)
10.)Patience and a strong back!!

Here is a list of what NEEDS to be done in order for the best lash adjustment possible:

1.)Feeler gauge clearances need to be checked between the rocker arm tip and the end of the valve, see picture for reference.
2.)All valves lashes need to be adjusted at TDC of the targeted cylinder
3.)Get to know your feeler gauge. As dumb as that may sound, you’ll thank yourself because a lot of times people go in there and don’t know what to look for when using the feeler gauge.
4.)When using the feeler gauge, you need to have a nice drag on it between the rocker arm and the top of the valve. You don’t want to yank it out and you don’t want to be able to pull it out with no resistance at all, just a real nice drag.
5.)Firing order of the engine is 1-3-4-2. This will be referenced to later

Lets get started:

First, we want to remove plug wires out of spark plugs, but not out of the distributor cap!!



Next, we want to remove the valve cover. It consists of 5 10mm bolts that are easily removed. Remove the bolts and remove the valve cover. I like to take the gasket with it and that will be explained later when you reinstall it.




Alright, now that the valve cover is removed, here is your working environment. Don’t get intimidated, it’s not hard at all. The cylinders are labeled and numbered for your reference. On this particular motor (d16z6), there are 16 valves total. Most d series are like this, which means you will adjust 4 valves on each cylinder. 2 intake and 2 exhaust.




Now remove the distributor cap (do not remove plug wires from the cap). This is done by removing the three phillips screws.



Once removed, you will see the rotor, which is pictured here. The metal piece on the arc of the rotor is going to be our reference. The piece is about ¾” long, so just use the middle of it. What I did was mark each cylinders plug wire so I could easily verify which cylinder I was on.



Once everything on the rotor is situated and ready to go, you can now remove the spark plugs. I highly recommend removing the plugs because it will release the compression and make the engine a lot easier to bar over.


 
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#2 · (Edited)
Now, it is time to begin barring the engine over. I like to start with cylinder number 1 because it is the first in the firing order of the engine. You will need the 17mm deep socket. Put it over the crankshaft pulley bolt and get ready to give it a good turning. For some it may be difficult at first, but once you get it going, it will be all good from there. Be sure to turn clockwise, which is toward the front bumper. Here is the bolt to turn:



How to know when you are at cylinder number 1’s TDC of the compression stroke is very simple. Stick that wire that you have down cylinder number 1 spark plug hole into the cylinder. Be sure the wire is clean and dirt free just to be safe. Let the wire rest on the piston. Now, remember when you marked the distributor to the cylinders plug wire? Just turn the crankshaft clockwise (toward the front bumper) until the coil on the rotor is pointing at cylinder number 1 plug wire. As it gets closer to TDC, the wire that you stuck into the cylinder will begin to rise up with the piston. When it stops moving then you are at the TDC of the stroke, but I don’t like to rely on just the wire……I get up frequently to check the rotor to make sure I haven’t yet passed up my goal. (Please note that just because the wire comes up, doesn’t mean that the engine is on its compression stroke. That is the purpose of using the rotor as reference.) Give the rockers a jiggle up and down, they should be loose and able to move a little bit. There should be no resistance at all from the rocker arms to the valve.

Piece of wire:


Picture of how where rotor should be pointing for TDC on cylinder #1:


Once you are 100% sure that the cylinder is at TDC of the compression stroke, it is time to adjust the lash for that cylinder. Here is want you want to look for…this is the correct place to check for clearances. Sorry for the crappy drawing………but you get the picture, hopefully

Where to check spec at with feeler gauge:


For the intake side, you want to use .007”-.009” For the exhaust side, you want to use .009”-.011” Note how there is a range of clearances that can be used. This is a good thing because you can have a little bit of error on your adjustments. I recommend using .007” for the intake valves and .009” for the exhaust.



Lets begin adjusting them. First, go ahead and check to see how loose or tight they are compared to what the spec should be. This can be for you benefit to see how bad they were out of spec. Once you’ve done that, loosen the 10mm nut that is on top of the rocker arm. Once it is loose, stick the feeler gauge in the correct location which is between the rocker arm tip and the tip of the valve. With the feeler gauge inserted, slowly tighten or loosen the flathead screw while after each adjustment you give the feeler gauge a movin around to feel the clearance you are at. Once you get the desired clearance, which is a nice drag on the feeler gauge, tighten the 10mm nut back down being very careful not to turn the adjusting screw. Once tightened down, check clearance on it again to be sure you didn’t move the screw while tightening the nut down. If it specs out to you satisfaction, move to the next valve doing the same procedure.


 
#3 · (Edited)
Once you are complete with cylinder number 1, give all of them one last check down for clearances making sure that they are all precise. Also make sure that all nuts have been tightened.

Once cylinder number on is complete, move to cylinder number 3. Insert the wire into the cylinder via spark plug whole, just like you did for #1. Once in and resting on the piston, start barring the crank over with the 17mm deep socket and ratchet. Be sure to check the rotor after every so many turns. Your goal is to have to coil of the rotor pointing at cylinder number 3 spark plug wire that you marked down for your reference earlier.




Once you ensure you are at cylinder number 3 TDC of compression storke, perform each step as you did for cylinder number one, being sure to be consistent with clearances and the amount of drag on the feeler gauge. Check frequently making sure you are using the correct size gauge for the correct valve. Once again, its .007” for intake and .009” for exhaust. Torque down all nuts one last time to be sure they are all tight and then give each valve on least feel with the gauge making sure the clearances you adjusted are still in spec.



Now move to cylinder number 4. Stick the reference wire donw the spark plug whole and rotate the crankshaft until the wire is all the way up and the rotor in the distributor is pointing at cylinder # 4 plug wire.




Once cylinder 4 is at TDC, check the clearances of the valves as you did previously for cylinders 1 and 3. Adjust as necessary and check clearances on last time before moving to next cylinder. Also, check to make sure the nuts are all tightened down.

 
#4 ·
Now its time for the last cylinder in the firing order which is number 2. Place the wire down the spark plug hole of cylinder number 2. Let it rest on the piston. Being to turn the crankshaft until the wire is all the way up and the rotor in the distributor is pointg toward cylinder # 2 plug wire.




Like previously, adjust all clearances as neseccary being as consistant and presice as possible. Be sure to double check clearances before reinstalling valve cover and be sure all nuts are properly tightened.



Once complete with cylinder # 2, then you finished. You must reinstall the vlave cover and valve cover gasket. I like to wipe the head and the gasket down so it gets a good seal.

wiping down head where gasket will be placed.


Unfortunately my camera died so i couldnt get any reinstall pics of anything. But, its not hard, its the same as when you took it off. Just reinstall the cap on the dizzy, and be sure that when you reinstall the vlave cover that you dont over-torque the bolts and break them. Its also best to screw them in as a cross pattern to give it a good seal. Reinstall spark plugs and you are finished. Start it up and give it a listen.

hope this is a good diy and it helps someone out!!
 
#5 ·
also, i know there are other ways to tell TDC of the cylinder, but this is how i did it and it has worked very well. If you have other ways that you feel may work better, feel free to post them up
 
#6 ·
Awesome Man.I completely understand too.Really well layed out,anyone should be able to understand that.I've haven't heard of The term 'Valve lash adjustment' but I'm pretty sure here in OZ we say 'Valve clearance adjustment'.So I did know what you were talking about but had No idea how to do it.I am talking about the same thing aren't I?
 
#7 ·
yeah, some people call it valve clearance, some call it adjusting the overhead, and some call it adjusting the valve lash.......but yeah, hopefully this diy helps some people out. i tried to get as many pics as i could, but unfortunately my camera battery died at the end so i could get any reinstall pics, but those are pretty straight forward.
 
#10 ·
QFT.

I usualy just use a long 3/8 drive extention. It fits nicley through the spark plug hole. When i get the engine at TDC, I mark the extension with a sharpie, pull it out, and wrap a ring of tape around it. Then when looking for TDC, I match the tape line up with the very end of the spark plug tube. Its accurate every time and repeats quickly. I used to use wire/coat hanger, but its not sturdy enough IMO, and tends to move around on the piston causing me to check for TDC for like an hour, lol.
 
#14 ·
if you turn the wrench toward the fron bumper.....then the crank is moving clockwise. If you turn the other way, you will loosen the crankshaft pulley bolt.
 
#18 ·
Great writeup! Would have been nice if I had this to reference when I did mine a month or so ago.
 
#19 ·
so...what would happen if you did the valve lashes while on the "exhaust TDC" - what are the symptoms...i mean... :hammer:
 
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#21 ·
That's a fair question, I would think that regardless at TDC there will be no cam tension on the valvetrain so you should be fine, feel free to correct me though.
 
#22 ·
alright, well counterclockwise it is then.

sorry about the confusion with that.....hopefully everything else looks good on it!!

thanks for the responses:TU:
 
#23 ·
i know i am like a week late, but i had always wanted to try this but have been intimidated. good write up. what differences did you feel? improve gas mileage? how far out of specs were the valves?
 
#24 ·
another way I do it is fairly simple and works.

1 -3-4-2 sequence.

I put my finger on the cam lobe to "feel" when the pointy bit of the cam is facing down, i.e. rockers resting on the base of the cam lobe.
Slip feeler gauge in and adjust.
Repeat with intake/exhaust of same cylinder.
 
#25 ·
ehhh.......i dont think i would do it that way, but thats just my opinion. The way i see it, if your taking the time to be in there to take the time and adjust them, you might as well use at least something to stick down the spark plug hole to make sure its all the way at the top of the stroke. im sure your way works great, but i just dont think i would feel comfortable doing that.
 
#26 ·
my way........

#1 to TDC, you got timing marks for that right?

set lash, spin crank 180 degrees. 24" 1/2" drive extension makes this easy!

set #3 lash

again 180 degrees, check crank pulley to be sure

set #4

another 180 degrees

set #2 and be done.

It is THAT easy.

I could post the shortcut, but that will confused more people, they will ask more questions.....so no.

18436572
 
#29 ·
Yeah......may be a little more difficult, but ive never done it. but yeah, same basic thing. if you can use a feeler gauge you can it.
 
#31 ·
good write up, I like to set it .001 tighter then stock just for that extra micron of lift hahahah.
 
#34 ·
good stuff man!!! easy to understand steps!!

i do mine like how bones said he does his... just keep turning the crank pulley 180deg at a time... plus keep referencing to the camgear... only because i haven't adjusted the cam timing!!

:TU:
 
#36 ·
if you do everything correctly and dont loosen the crankshaft pulley somehow (which is HIGHLY unlikely) then no, no adjustments will need to me made. Adjusting vlavle lash simply adjust the space between the roker arm and the vlave stem, thus adjusting how far the valve opens.....
 
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