Conduct a Valve Clearance Adjustment, K20a2/3 engines

[Lestat537]

BlasTech this is for you! =) tickatickatickaticka tickaticka :wink:

Disclaimer: I will not be held responsible for anybody screwing up their engines! If in doubt, bring your car in to the dealer for this type of work. This is only for the mechanically inclined. =) If you don't know how to use a feeler gauge and can't find anybody to show you HOW to use one, you are strongly advised to not use this procedure.


Special Tools Required:: You'll have to find a really cool Service Department to get these tools.
Here's a pic:

Adjuster 07MAA-PR70110 (For easy reference, you'll want to mark a big X on the top of the adjuster)
Locknut wrench 07MAA-PR70120

Other Tools required::
Feeler gauge (non-honda specific)
17mm combination wrench
19mm Deep Socket
Long Extension
Micro Torque Wrench (helpful) or if you're used to torquing bolts to low values, this can be skipped

Be sure to conduct this procedure only when the cylinder head temp is below 100F.

Remove cylinder head cover. I won't go into detail with this because it should be fairly straightforward.

Set the No. 1 piston at TDC: The punch mark on both the exhaust camshaft sprocket and the VTC actuator should be at the top. The TDC marks should be aligned, facing each other. (Note: If you don't know how to set the No. 1 piston at TDC, which piston is the No. 1 Piston, or you don't know which sprocket is the exhaust sprocket and which is the VTC actuator, this should clue you in on NOT doing this procedure yourself!)

Select the correct thickness feeler gauge for the valves you're going to check. Here's the factory specifications for corresponding engines:

K20A3 engine
Intake:
0.21-0.25 mm (0.008-0.010 in.)
Exhaust:
0.28-0.32 mm (0.011-0.013 in.)

K20A2 engine
Intake:
0.21-0.25 mm (0.008-0.010 in.)
Exhaust:
0.25-0.29 mm (0.010-0.011 in.)
Insert the feeler gauge between the adjusting screw and the end of each valve stem. Slide it back and forth, and you should be feeling a little drag. If according to the feeler gauge it is too much or too little drag, keep the correct feeler gauge there and break out the special tools.

Using the Locknut wrench, position it above the adjusting screw locknut on the rocker arm you choose first (usually I do the two on the exhaust side before the two on the intake side -- I like to get the more difficult ones out of the way) and slide the adjuster wrench down inside the locknut wrench and gently twist the adjuster until the blade engages the adjusting screw.

Loosen the adjusting screw locknut with the open end of the 17mm combo wrench 1/4 turn counterclockwise. Now that the feeler gauge is inserted and the adjustment screw locknut is loose, you can either turn the adjustment screw itself (using the Adjuster of course! it can be turned easily now by hand) clockwise to reduce clearance or counterclockwise to increase clearance.

Be careful as you do this, because twisting the adjuster by a mere few degrees can push your valve clearances out of spec. You must be proficient at using a feeler gauge, as explaining it in text is almost impossible!

Once you've dialed in the correct clearance, maintain the adjuster tool's position (keeping an eye on that handy X you painted) and tighten the adjustment screw locknut to its specified torque below:

K20A3 engine:
Intake:
20 Nïm (2.0 kgfïm, 14 lbfïft)
Exhaust:
14 Nïm (1.4 kgfïm, 10 lbfïft)

K20A2 engine: 20 Nïm (2.0 kgfïm, 14 lbfïft) both Intake and Exhaust
After tightening, always check and recheck valve clearances. Do this twice after you are done with each cylinder.

For the other three cylinders, make sure the one you are working on is at TDC.

Cylinder #2 TDC:: VTC actuator TDC mark is at top, exhaust sprocket TDC mark is at bottom
Cylinder #3 TDC:: VTC actuator and exhaust sprocket TDC marks are opposite each other, furthest apart
Cylinder #4 TDC:: VTC actuator TDC mark is at bottom, exhaust sprocket TDC mark is at top

When you are finished, check the valve clearances once more, it takes only a few minutes and will save your engine.

Put the cylinder head cover back on:: Check the seal on it to make sure they have not deteriorated. Before it is put back on, I like to flash a light and stick my nose right up to the head to check for anything that might have fallen in during the procedure. After the cover is back on but before you tighten it down, bust that flashlight out and inspect the head cover seal. Take the head cover off and apply liquid gasket if you need to.

Tighten the bolts in two or three steps, to 9.8 N m (1.0 kgf m, 7.2 lbf ft) in this order:: Lower middle, upper middle, lower left, upper left, upper right, lower right (When looking at the head cover while standing in front of the car). Overtorque by too much, and you'll crack the head cover, or worse yet, a stud.

Once everything is back on, start the engine and run it for 5 minutes while checking for oil leaks around the cover seal.

Edit 06.14.04: Added picture of the Honda valve adjustment tools

[rsxmachine]

having done mine twice I found this previous illustrated article very helpful:
http://www.vtec.net/articles/view-article?article_id=1 43824

I used a deep socket and a screwdriver, didn't seem to need the special tools... loosen the locknut only a little, just enough to allow the adjustment screw to turn. then after fine-tuning the valve clearance, hand-tighten the locknut with the socket; the locknut can then be torqued to spec without altering the clearance.

agree about rechecking the clearances a few times; once you get the hang of it, it goes quickly.

you should put a dab of Hondabond gasket sealer on each corner of the head where the valve cover rests before reinstalling it (remove old silicone first).

[02silverSI]

Just wondering does anyone know what the part number is for the adjuster in the snap-on line of tools?

[thaduke2003]

You really don't need the specialty tool man- the Snap-On tool is about $130 for something you can just use a wrench and screwdriver (maybe $3 for both) for- don't be silly, unless you do this for people every tuesday :) Mark W.

[GeoPup]

A socket held by a Vise Grip will work as an adjustment tool - credit for this idea goes to a person who has a personal page on valve clearance for Honda CR-V gen. 1

[rsxmachine]

^ hell yeah chalk another one up for the redneck toolbox

-vise grips
-leatherman
-pry bar
-bailin' wire
-duck tape
-WD-40
-JB Weld
-B.A.H. (a brick will do)

you could goddarn near fix the Titanic even.

[paulkramer]

OK, I put my flame suit on and I'm bumping this thread.......all the way from 11/2005!!

I'm doing it because it's the only valve clearance adjustment thread I have found here or on crsx.com.

I am a noob to checking my own valves, but I bought a set of feelers from Snap-On, and cracked open my valve cover today.

It seemed to me (using the specs from the Helms) that every valve was within 1/100" of each other, and within the range listed in the Helms.

But - when the Helms says "adjust if too much or too little drag" sort of leaves me wondering - how much is just right? I'm sure it comes with experience, and/or having someone else demonstrate the proper amount of drag.

Also, I'm sure it is critical to have the engine at TDC, yet how can you tell if the cam markings are pointing exactly skyward - for cylinder #1, or exactly 90 degrees from skyward, etc. for the other three?!

My car has 64K on it, I just wanted to check and see for myself how the valves were doing. I didn't adjust anything, and I hope that I did right.

Anyway

[paulkramer]

Hmm.....did I surpass a maximum length with that last post?

[paulkramer]

^ hell yeah chalk another one up for the redneck toolbox

-vise grips
-leatherman
-pry bar
-bailin' wire
-duck tape
-WD-40
-JB Weld
-B.A.H. (a brick will do)

you could goddarn near fix the Titanic even.

If they'd had duck tape back then, the Titanic would still be with us.

[rsxmachine]

But - when the Helms says "adjust if too much or too little drag" sort of leaves me wondering - how much is just right? I'm sure it comes with experience, and/or having someone else demonstrate the proper amount of drag.it's similar to gapping a spark plug. the chosen feeler gauge should slide in between the valve stem & tappet with a slight amount of drag/friction but you shouldn't need to force it. use the next larger size (+.001") gauge to check -- it shouldn't fit all the way in.

the turn of the cam gears isn't exact, they point a little left of skyward due to the angle that the engine sits at, and you'll feel some slack as each set of valves closes. go by turning the crank 180° each step. take the time to check/adjust each set of valves twice and you'll be good to go.

[paulkramer]

it's similar to gapping a spark plug. the chosen feeler gauge should slide in between the valve stem & tappet with a slight amount of drag/friction but you shouldn't need to force it. use the next larger size (+.001") gauge to check -- it shouldn't fit all the way in.

the turn of the cam gears isn't exact, they point a little left of skyward due to the angle that the engine sits at, and you'll feel some slack as each set of valves closes. go by turning the crank 180° each step. take the time to check/adjust each set of valves twice and you'll be good to go.

Thanks, machine.

I used three or four gauges per valve - there are three English gauges that are within the specs listed in the Helms. I tried the middle one first, and if that felt loose, I moved up one. I felt it was OK if I was unable to insert the first gauge (increments of 1/100") beyond the listed specs. Actually, once or twice I could almost get the next size up to slide in, but not all the way.

Would be easier task with stepped gauges......and one dedicated for exhaust and one for intake. I have a ~20 blade set, where they flip around out of a handle and you tighten a screw to hold the desired gauge in place. No matter how tight the set screw was, with the tight spaces in the engine compartment it was hard to keep the gauge from slipping around and/or to place it at the correct angle.

Does anyone know (I already asked a Honda tech on crsx, he said they get theirs from Snap-On, etc.) of a set of gauges that aren't all bundled together like mine. I only need two stepped gauges for this car, not a whole set of extras that get in the way.

[paulkramer]

the turn of the cam gears isn't exact, they point a little left of skyward due to the angle that the engine sits at, and you'll feel some slack as each set of valves closes. go by turning the crank 180° each step. take the time to check/adjust each set of valves twice and you'll be good to go.

The Helms drawings seemed to indicate that the markings on the cam gear should be square with the ground, rather than the top of the engine. In other words, the diagram shows cylinder #1 at TDC when the arrow on the cam is pointing straight up at the sky, which is also the position where the two notches on the cams are aligned. I thought that was weird - that the arrow should be pointing skyward, but slightly towards the back of the car - in other words, at 90 degrees to the plane of the surface of the head.

That seems to be what you are saying too. Which way is correct?

:confused:

[solar]

$130 at the Honda Dealer was the easiest way to go for me, no more ticky tack.

[rsxmachine]

^I'll do it for half that :)


Does anyone know (I already asked a Honda tech on crsx, he said they get theirs from Snap-On, etc.) of a set of gauges that aren't all bundled together like mine. I only need two stepped gauges for this car, not a whole set of extras that get in the way.

take the set of gauges apart, and just use them individually.

[rsxmachine]

The Helms drawings seemed to indicate that the markings on the cam gear should be square with the ground, rather than the top of the engine. In other words, the diagram shows cylinder #1 at TDC when the arrow on the cam is pointing straight up at the sky, which is also the position where the two notches on the cams are aligned. I thought that was weird - that the arrow should be pointing skyward, but slightly towards the back of the car - in other words, at 90 degrees to the plane of the surface of the head.

That seems to be what you are saying too. Which way is correct?

:confused:
the Helms diagram is pretty accurate, the arrow on the cam gear will be just past the edge of the chain guide when #1 is at TDC. you can also feel/see when the cam lobes are not pushing on the valves on the cylinder you're working on. once you get #1 at TDC, it's a simple matter of turning the crank 180° to get the next cylinder to TDC (in 1-3-4-2 order that is).

[paulkramer]

$130 at the Honda Dealer was the easiest way to go for me, no more ticky tack.
See, that's my problem. This is my first Honda; I don't know how it's supposed to sound! :(


^I'll do it for half that :)
take the set of gauges apart, and just use them individually.

Oh, yeah - duh! :embarasse


the Helms diagram is pretty accurate, the arrow on the cam gear will be just past the edge of the chain guide when #1 is at TDC. you can also feel/see when the cam lobes are not pushing on the valves on the cylinder you're working on. once you get #1 at TDC, it's a simple matter of turning the crank 180° to get the next cylinder to TDC (in 1-3-4-2 order that is).

Thanks again!