Valve Clearance Check and Adjustment

[melbourne]

Vehicle = 1994 Civic 16 Valve SOHC 1.5l

Okay, this may be a lengthy post but if anyone can identify any flaws in the following procedure for adjusting valve clearances would be much appreciated. This post follows up on the Valve Adjustment Help post.

1.. Stop the vehicle (obviously).
2.. Put in neutral.
3.. Allow the engine to cool for at least 4 hours so that the engine is cold or let the car cool overnight and conduct this procedure in the morning.
4.. Remove the valve cover.
5.. Remove the distributor cap.
6.. Place cylinder number one (this is the cylinder closest to the timing belt) at Top Dead Centre (TDC).
7.. To do so, jack the front of the vehicle closest to the timing belt and remove the wheel.
8.. Via the wheel cavity, using a ratchet with a socket extension, rotate the crankshaft pulley clockwise until the timing pointer on the block lines up with the TDC mark on the front pulley.
9.. The distributor rotor must also be pointing towards the number one spark plug wire terminal on the distributor cap.
10.. Once in this position, the valve clearances can now be checked
11.. Start with the intake valves and insert a feeler gauge with a thickness of 0.007 to 0.009 inches between the valve stem and rocker arm. As you withdraw it, there should be a slight drag. If not, tighten the adjuster screw until you feel a slight drag on the feeler gauge. This is done by holding the adjuster screw with a screwdriver to prevent it from turning and tighten the locknut. Recheck the clearance to make sure it is correct and repeat for the other intake valve. Then do the same for the 2 exhaust valves but with a thickness of 0.009 to 0.011 inches.
12.. Once cylinder one is completed, rotate the crankshaft pulley 180 degrees counter-clockwise until number 3 cylinder is at TDC, the distributor rotor pointing to the number three spark plug wire and the camshaft sprocket on the exhaust side. Check and adjust as per step 11.
13.. Once cylinder three is completed, rotate the crankshaft pulley 180 degrees counter-clockwise until cylinder number 4 is at TDC, the distributor rotor is pointing to number 4 spark plug wire and the camshaft sprocket is pointing downwards. Check and adjust as per step 11.
14.. Once cylinder four is completed, rotate the crankshaft pulley 180 degrees counter-clockwise until cylinder number 2 is at TDC, the distributor rotor is pointing to number 2 spark plug wire and the up mark on the camshaft sprocket is on the intake side. Check and adjust as per step 11.
15.. Once all the valves have been checked, replace the valve cover and torque the valve cover nuts to 9.5 NM

In addition, is there any other way one can determine where the distributor rotor is pointing without having to remove the distributor cap? I have seen mechanics adjust the valves without removing the distributor cap.

 

[David Brodbeck]

Before you start, I recommend removing all four spark plugs. This makes
the engine easier to turn over. This is a good time to check the spark
plugs for wear and regap them if necessary. When you reinstall them,
use anti-seize. (On the threads only, please! Don't get any on the
electrodes or insulator!)

11. Start with the intake valves and insert a feeler gauge with a
thickness of 0.007 to 0.009 inches between the valve stem and
rocker arm. As you withdraw it, there should be a slight drag.

Press down on the other end of the rocker as you check the clearance, to
make sure any slack is out of the valve train.

In addition, is there any other way one can determine where the
distributor rotor is pointing without having to remove the distributor
cap? I have seen mechanics adjust the valves without removing the
distributor cap.

You can look at the cam lobes. The cylinder that is at TDC will have
both valves closed (on the low parts of the cam lobes.)

On the other hand, removing the cap doesn't take long, and this is a
good time to inspect your distributor rotor and the inside of the
distributor cap for wear. I pull the wires off the spark plugs and
leave them attached to the cap. On a Civic, at least, the lengths of
the wires are such that if you do this, you can't possibly plug them
back into the wrong spark plugs.

 

[dimmi]

Your sequence is ok except you can work on the cylinder head once it has
cooled down past 50 Celsius. No need to wait overnight.
David has pretty much pointed out the all important details.
I personally always go only by the camshaft gear and its timing marks plus
look at the valves. But it is always BETTER to double-check everything by
removing dist cap.
Don't forget to torque 10 mm nuts on the rocker arms to 12 lbs/foot.

 

[melbourne]

Thanks David!!

Could you confirm that the valve clearance I specified are correct.

Intake valves 0.007 to 0.009 inches
Exhaust valves 0.009 to 0.011 inches.

In addition, could you please clarify your point:

You can look at the cam lobes. The cylinder that is at TDC will have
both valves closed (on the low parts of the cam lobes.)

 

[melbourne]

Thanks again dimmi!!

Could you please clarify

I personally always go only by the camshaft gear and its timing marks plus
look at the valves.

Also, are all 16 (intake and exhaust) nuts on the rocker arms 10mm. Are
they all torqued to 16.3 NM (I hope my conversion is correct)?

 

[Mr. Speck]

hello melbourne, et. al.

I just did my valve clearance check TODAY... went late into the
night-- my first time and so i didn't wanna screw anything up-- but it
was definitely educational. I have Chilton's and Haynes-- it looks
like you got your directions from Haynes... here are some other
things they don't tell you in there that would've helped my
newbie-don't know shit-self:

the camshaft is the pulley with the timing belt -- the one with the
cover on it-- right next to the valve cover. It is NOT the power
steering pump pulley. It was only after I spent an hour trying to
find the markings on the power steering pump pulley that i realized,
maybe the camshaft pulley is under the cover. (i'm real smart like
that).

the camshaft cover doesn't come off until you get the valve cover off.
And even then it took me forever-- is there a trick!? a very hard
hose (i think it's part of the radiator system) kept me from being
able to get the camshaft cover off without a LOT of yanking and
tugging and praying i'm not about to break something.

when i finally got my valve cover off-- a couple of the spark plug
seals stuck with the cover, while the other two stayed stuck onto the
head-- not sure if that's something to worry about or not-- i just let
it be like that and it still seemed to get put back together ok when i
put the cover back on.

trying to adjust the valve with the feeler gauges i had was
challenging-- I was using the same specs you stated, so i chose a .008
in. feeler gauge for the intake and a .010 in. for the exhaust. The
problem I found was that when you're measuring with the feeler gauge,
a "slight drag" is always achievable no matter how loose the valve is.
It's extremely sensitive to the angle you hold the gauge, and it's
very difficult to get it at just the right angle so it's completely
perpendicular with the valve. It's only when you get it at this
orientation that you achieve the least drag, and i assume the drag you
should measure (is this right?). This is further complicated by the
fact that the intake valves are angled down below the edge of the
gasket, so I had to permanently bend my .008 in. feeler gauge 90
degrees in the middle to be able to fit it in without bowing it-- if
you bow it it's impossible to tell whether there's a slight drag or
not, cuz you'll always feel a drag since it's bowed. Anyone got any
better ideas here!?

the adjustments are also extemely sensitive. Going from no drag to
slight drag to very hard drag is such a small turn of the screw as to
be hardly perceptible.

but even with all these questions and problems i forged ahead and got
it done-- haven't tried starting the car yet-- i doubt it'll be a
problem though-- i'm assuming the valves didn't need much adjusting
(not sure if they really needed any, maybe i'm just being anal).

But I do still have a few outstanding questions if anyone can answer
them (in addition to those scattered above):
why do you have to turn the crankshaft clockwise first and the
counterclockwise-- does it matter? I mean could i do it in the
reverse order if i turned it clockwise-- and does the initial setup
have to be turned clockwise? I assume the face of the clock is the
side of the crankshaft you put your socket wrench in?
also-- why do you have to have it in neutral-- i had mine in first--
is that bad?
do you have to have it exactly on the TDC marks!? or is there some
leeway?

anyway-- hope that helps a little-- hopefully others can help more...
happy valve tuning!
-mr speck
(mine is a '95 1.5L civic so i imagine it's exactly the same as yours)

p.s. what dimmi was saying was that when you open up the valve
cover-- there are lobes on the camshaft axel that cause the rockers to
go up and down... you'll see when you turn the crankshaft. when a
cylinder is at TDC then both valves are closed, the rockers are
resting on the lowest part of the camshaft lobes, and therefore they
are raised at the ends-- you'll see when you open it up-- you don't
need to open the distributor.

 

[Gordon McGrew]

hello melbourne, et. al.
the camshaft is the pulley with the timing belt -- the one with the
cover on it-- right next to the valve cover. It is NOT the power
steering pump pulley. It was only after I spent an hour trying to
find the markings on the power steering pump pulley that i realized,
maybe the camshaft pulley is under the cover. (i'm real smart like
that).

(snicker cough cough)

when i finally got my valve cover off-- a couple of the spark plug
seals stuck with the cover, while the other two stayed stuck onto the
head-- not sure if that's something to worry about or not-

not. I would peal it off the head and stick it into the valve cover.

- i just let
it be like that and it still seemed to get put back together ok when i
put the cover back on.

Some people replace the o-rings and the big gasket each time. Since
you didn't do that, just drive it a couple thousand miles and check
for leaks, both around the cover and into the spark plug well.

trying to adjust the valve with the feeler gauges i had was
challenging-- I was using the same specs you stated, so i chose a .008
in. feeler gauge for the intake and a .010 in. for the exhaust. The
problem I found was that when you're measuring with the feeler gauge,
a "slight drag" is always achievable no matter how loose the valve is.
It's extremely sensitive to the angle you hold the gauge, and it's
very difficult to get it at just the right angle so it's completely
perpendicular with the valve. It's only when you get it at this
orientation that you achieve the least drag, and i assume the drag you
should measure (is this right?). This is further complicated by the
fact that the intake valves are angled down below the edge of the
gasket, so I had to permanently bend my .008 in. feeler gauge 90
degrees in the middle to be able to fit it in without bowing it-- if
you bow it it's impossible to tell whether there's a slight drag or
not, cuz you'll always feel a drag since it's bowed. Anyone got any
better ideas here!?

the adjustments are also extemely sensitive. Going from no drag to
slight drag to very hard drag is such a small turn of the screw as to
be hardly perceptible.

They sell pre-bent feeler gauges for next time. As for setting the
valves; keep in mind you are doing a high precision operation, i.e.
one designed to allow humans to easily achieve super-human accuracy.
That huge difference with a small turn is actually a very small
difference in adjustment. Think of it this way; somewhere in that tiny
fraction of a turn is the perfect setting. If you set it in the
middle, how far from perfect can you be? IOW, don't sweat it too
much.

but even with all these questions and problems i forged ahead and got
it done-- haven't tried starting the car yet-- i doubt it'll be a
problem though-- i'm assuming the valves didn't need much adjusting
(not sure if they really needed any, maybe i'm just being anal).

The one mistake you made was not checking the measurement before
loosening the valve adjustment. Try using the next higher and lower
gauge to determine if the valve is getting looser, tighter or holding.
This will allow you to judge when you need the next adjustment. Back
when they wanted you to check it every 15K, it was not uncommon not to
actually adjust any of the valves - or maybe just a few slightly.

But I do still have a few outstanding questions if anyone can answer
them (in addition to those scattered above):
why do you have to turn the crankshaft clockwise first and the
counterclockwise-- does it matter?

doesn't really matter but normally you would keep going in the same
direction. Surprised your manuals aren't explicit on this.

I mean could i do it in the
reverse order if i turned it clockwise-- and does the initial setup
have to be turned clockwise? I assume the face of the clock is the
side of the crankshaft you put your socket wrench in?
also-- why do you have to have it in neutral-- i had mine in first--
is that bad?

(cough) If it is in gear, the car moves when you turn the engine. No
harm, but only benefit is building up your biceps - especially if the
hand brake is on. Put it in neutral. Or, if you have room, skip the
wrench altogether and put the car in fifth gear and push it to turn
the engine.

do you have to have it exactly on the TDC marks!? or is there some
leeway?

It should be as close as possible. A millimeter or two off probably
won't have any measurable effect.

anyway-- hope that helps a little-- hopefully others can help more...
happy valve tuning!
-mr speck
(mine is a '95 1.5L civic so i imagine it's exactly the same as yours)

Hats off to you Mr. Speck. It takes a good amount of courage and
perseverance to carry out a job like this when you are starting with
limited knowledge of the machine you are working on.

 

[Mr. Speck]

(cough) If it is in gear, the car moves when you turn the engine. No
harm, but only benefit is building up your biceps - especially if the
hand brake is on. Put it in neutral. Or, if you have room, skip the
wrench altogether and put the car in fifth gear and push it to turn
the engine.

what do you mean push it? why fifth gear? why not 1st? isn't it
hard to push when it's in gear?-- i mean isn't that like putting it in
Park for an automatic.

 

[dimmi]

there are about 4 sets of timing marks on the camshaft gear and upper back
timing plate (backing plastic cover) on my both Civics. Each set is for a
different model and engine (D16Z6, D15Z1, D15B7, etc). I hope Australian
models came with kinda same hint.

Camshaft timing marks has all the info for you to have every given cylinder
in TDC (when valves are closed - there is a gap between butt of the valve
and tip of the rocker arm for both EX and IN) as far as valve lash
adjustment is concerned. No need to look at the crank marks or distributor
rotor (however, as I said, it is always good to DOUBLE CHECK).

Locknuts 10 mm with 7*0.75 thread on my cars . Can't you check it out
yourself?

As far as the torque:

Intake and exhaust valves locknuts:
D16Y3,D14A2 18 NM
D15B7, D15B8 14 NM
DO NOT OVERTIGHTEN ABOVEMENTIONED BECAUSE ROCKER ARMS ARE MADE OF ALUMINUM

D16Y2, D15Z3, D16Z6, D15Z1 20NM

Valve cover bolts:
D16Y2, D15Z3 9.8 NM
D16Z6, D15Z1 10 NM

HTH

dimmi

 

[dimmi]

agree with you Gordon. These two guys (melbourne and Mr. Speck) are
something ;-))) Well, the whole idea of having this forum is to help - and I
hope we all are ready and glad to help!

 

[dimmi]

you have the correct gap specs.
It would be easier to adjust lash if you would designate several feeler
gauges explicitly for this task, because you NEED to bent them at 90
degrees. L-shaped gauges will allow you a more precise adjustment, you'll be
able to get into a tight spot and eliminate drag caused by the obvious
"angling" of the gauge, described by Mr. Speck in the next post.

dimmi

 

[dimmi]

But I do still have a few outstanding questions if anyone can answer
them (in addition to those scattered above):
why do you have to turn the crankshaft clockwise first and the
counterclockwise-- does it matter? I mean could i do it in the
reverse order if i turned it clockwise-- and does the initial setup
have to be turned clockwise? I assume the face of the clock is the
side of the crankshaft you put your socket wrench in?

Honda engines are probably one of the few that rotate COUNTERclockwise
(actually I am not aware of ahy other manufacturer). Therefore, for the
valve lash adjustment, you should rotate crank countercw in order to
reproduce real environment. If you turn it cw during valve adj, I would
think, it may cause unnecessary error in your timing: there is a slack on
the tim belt, maybe some play between teeth on the belt and teeth on the
gears and so on. I tried cw - it is different as far as timing. I do it
countercw to be on the safe side, anyway.

there are times when you have to play with your crank by rotating it
countercw or cw, for example installing new timing belt and adjusting its
tension.

also-- why do you have to have it in neutral-- i had mine in first--
is that bad?

no problem here - it makes no difference as to which gear you have it in. It
is easier to rotate crank if it is in neutral or 5th (5th or other
gear -only if the both front wheels are jacked up). But if say you jack up
only FR L wheel, then by rotating crank with tranny engaged you may injure
yourself.
logically and for the safety you HAVE TO HAVE IT IN NEUTRAL!!!

do you have to have it exactly on the TDC marks!? or is there some
leeway?

I would think, the less play, the less error, the more precise your project
is.
Yes, HAVE THEM ALLIGNED EXACTLY.

Correct me if I am wrong.

dimmi

 

[Paul Bielec]

what do you mean push it? why fifth gear? why not 1st? isn't it

hard to push when it's in gear?-- i mean isn't that like putting it in
Park for an automatic.

No, it is not.
An automatic transmission engages using oil pressure. That means that once
you start the engine, the ATF pressure builds up allowing the transmission
to engage the gears. The pressure changes with engine speed and this is what
makes the gear changes.
In other words, if the engine is not running, it doesn't matter in which
gear you are, the transmission will not engage. This is why you cannot start
an automatic car without the starter by pushing it and throwing it into a
gear. So the PARK is actually a lock mechanism inside the transmission that
locks the driveshafts.
While in with the standard tranny, you can engage any gear without engine
running. If you leave the car parked on a slope without the handbrake, it is
the engine compression the stops the car from moving. 1st gear and reverse
being the most efficient because of the gear ratio. If the car is old and
the engine worn out, the compression might be insufficient to stop prevent
the car from moving on a steep slope. I've seen that happening to someone.
The car was parked, then suddelnly we heard a FLOP.....FLOP...FLOP (sucking
noise) and the car backed up into the street and into the front lawn across
the street. Luckily there was no other cars.

 

[Gordon McGrew]

what do you mean push it? why fifth gear? why not 1st? isn't it
hard to push when it's in gear?-- i mean isn't that like putting it in
Park for an automatic.

It is harder to push in 1st gear than in fifth. You have to push it
farther to turn the engine a given amount but it is easier. (Helps a
lot if you take the spark plugs out.) Most people just put it in
neutral and use a wrench.

 

[David Brodbeck]

Thanks David!!

Could you confirm that the valve clearance I specified are correct.

Intake valves 0.007 to 0.009 inches
Exhaust valves 0.009 to 0.011 inches.

That's what my Haynes manual says for the 92-95 Civic, at least. I
didn't catch what car you have.

In addition, could you please clarify your point:

It's pretty simple. When you have the valve cover off, you'll see that
there's a rocker (a lever with a pivot in the middle) that opens and
closes each valve. One end rides on the cam lobe, the other presses on
the valve stem. The cam lobe is sort of egg shaped, and when the tall
part of it passes under the rocker it presses up the cam end of the
rocker, causing the valve end to press down and open the valve. If you
look at the cam you can tell whether the valve is supposed to be open or
closed by observing what part of the lobe the rocker is resting on.

(VTEC engines have an extra rocker between the two intake rockers, but
you don't need to adjust it so you can ignore it.)

If you're still hazy on this, turn the engine over by hand while
watching the cam. It will become obvious, I think.

 

[David Brodbeck]

what do you mean push it? why fifth gear? why not 1st? isn't it
hard to push when it's in gear?-- i mean isn't that like putting it in
Park for an automatic.

Park in an automatic actually locks the transmission. Putting a manual
transmission car in gear merely connects the engine to the wheels. It
makes it harder to push but not impossible. The higher the gear, the
slower then engine will turn when you push it and the easier it will be.
It will be *much* easier with the spark plugs out.

Personally I don't want to push the car around so I take off the front
wheel and use a socket on the crank pulley bolt, through the hole in the
fender well. You'll need a long extension. (Don't feel bad, by the
way. I spent a frustrating time the first time trying to turn the
engine over with the power steering pulley because I didn't know there
was a way to access the crank bolt.)

As for using a feeler gauge, it's a touchy feely thing (literally) and
it will take you some practice to get the feel for it. I like to hold
the blade between my thumb and middle finger and use my index finger on
the edge to push it into the gap, but whatever gives you the best feel
for what it's doing will work. Mostly I find that getting my fingers
close to the "business end" of the blade gives me a better feel than
holding onto the handle.

Another way to check is to try the next biggest or next smallest blade.
If the blade for the spec fits through with a bit of drag, the next
bigger one doesn't fit, and the next smaller one falls through easily,
you're in good shape.

 

[Stephen Bigelow]

The higher the gear, the
slower then engine will turn when you push it and the easier it will be.

Really?

Think.

 

[David Brodbeck]

Really?

Think.

I did think. Did you?

Let's say you're driving at 15 mph in 1st gear. How fast is the engine
turning? Now let's say you put it in 5th. How fast is it turning now?

 

[Stephen Bigelow]

I did think. Did you?

Yep. We're discussing pushing cars to turn the engine. Distance, not speed.

Let's say you're driving at 15 mph in 1st gear. How fast is the engine
turning? Now let's say you put it in 5th. How fast is it turning now?

Push your car 1 foot in 1st. How many times does the engine turn?
Now push your car 1 foot in 5th....

Ta-da.

 

[David Brodbeck]

Yep. We're discussing pushing cars to turn the engine. Distance, not speed.

Ever tried to push a car that's in 1st gear? There's a reason people
with broken parking brakes use that gear.