First valve adjustment

[hercdriver]

Let me start with, I am not even to the knuckle dragging stage of VW mechanic evolution.

I've got an unknown engine. Fan shroud says it a CB. Which makes it 1.7 liter IIRC.

It hasn't been driven much the past few months. About once a week I'll start it up and let it run for 5 to 10 minutes to let it warm up.

The last time I started it, it started to make a knocking noise. A loud knocking in my opinion. It sounds as though someone is tapping the valve covers with a small hammer. As a result, I concluded that I needed to do my first valve job. I also wanted to pull the push rods to inspect them.

I pulled the rods on the #1 cylinder, cleaned them with carb cleaner and replaced them back into their original homes. Both rods for the #1 cylinder were very clean and had no apparent damage. With the rockers reinstalled, I proceeded to try to adjust the valves to .006". This is where I'm running into problems. When I push the valve rocker to take the slack out, I get a lot of play. Which made me think that perhaps I have hydraulic lifters. Is there another way to tell? I'm also not sure if I'm at TDC for #1. I set the rotor so that it is pointed to the #1 plug. The fan wheel itself has no markings. Thinking that I was possibly 180 out, I turned the engine through anther full rotation of the distributor rotor with no apparent change to the gap issue.

Let me end with some questions.
1. Am I setting TDC correctly?
2. Could the noise have been hydraulic lifters that need oil?
3. Could you have hydraulic lifters in a 1.7 liter?


On a side note the last person to adjust the valves had them set so that about 3 or 4 threads of the set screw are showing. When I push down and adjust, I'm getting 10 to 15 threads.

Thanks,
Dave

[Gypsie]

first you need to confirm tdc. do what you have done and then pull plug #1. You may be able to see down the hole and see the top of the piston. if you can, move the crank back and forth a bit to see the piston move. You will also be able to feel when the pistons are at their turning point (top or bottom) as the crank will glide past that point
It will be much easier to turn if all the plugs are out anyway, just don't go getting carried away and drop something down in there.


I pulled the rods on the #1 cylinder, cleaned them with carb cleaner and replaced them back into their original homes. Both rods for the #1 cylinder were very clean and had no apparent damage. With the rockers reinstalled, I proceeded to try to adjust the valves to .006". This is where I'm running into problems. When I push the valve rocker to take the slack out, I get a lot of play.

I'm also not sure if I'm at TDC for #1. I set the rotor so that it is pointed to the #1 plug. The fan wheel itself has no markings. Thinking that I was possibly 180 out, I turned the engine through anther full rotation of the distributor rotor with no apparent change to the gap issue.

So, you turned the engine crank 2 complete revolutions? Then you came back to where you started.
You will need to turn the crank only 1 full revolution for the rotor to go 180 from start.
But
if the number one plug wire was where the rotor was pointing when you began your tdc process I think you are already in the zone and 180 off is not likely.


Look closer at your fan to find the marks. they may have been painted over. Do you have a timing scale? get the rotor to what you believe to be #1 and find your zero mark on the TS. There should be something on the fan. Look on the side of the fan nearest the case.


Then confirm if you have solids or hydros- Several ways'

get to the rocker arms and give em a good pull to push the rod into the lifter. if there is give with resistance then you likely have hydros.
Do all of the lifters as at least one should be in the cup and compressable.
No give=solids.

But
you have to confirm that your rods are centered in the lifter. They can easily sit at the bottom of the lifter when replaced which will give you a false setting when you set them. Confirm they are centered by looking down the tube to see that the rod is in the cup. It's a little contortionism (and worth seeing a pic of, if someone will take one and you post it ) but can be done. A mirror and good light may help.

Or
pull a lifter by removing rockers and tube to reach in there with a potent magnet to slide it out. those little telescoping dohickeys work great for this.


Your described symptoms are telling me that that you have hydrolic lifters and that at least one is compressed (more room for play has been left and they are tapping because thay have not "pumped up")

Hows your oil. 5 to 10 minutes at idle may not be enough to keep moisture from getting all into the works and gummin things up.


2. Could the noise have been hydraulic lifters that need oil?

they may need to be worked a bit to unstick if they are stuck. good warm oil and motion of the engine may help, but do the other checking first. Now that you've had your fingers in the pie you need to confirm it is at rights again before working them too much.


On a side note the last person to adjust the valves had them set so that about 3 or 4 threads of the set screw are showing. When I push down and adjust, I'm getting 10 to 15 threads.
When you say pushed down, are you pushing with any force? if solid there should be the >006 worth of clearance and then no room to move. with hydros you could be compressing the lifters sompletely and then setting them but when you let go the lifter will push against the rod and there will be no clearance whatsoever. You will be able to feel this with your fingers.

This is telling me that one or more of the above mentioned things are happening: 180 deg off , compressed lifters, rod not in lifter cup.
Also make sure that you have seated the rocker arm assembly properly.

If it was running good before and has started making the knocking from sitting, I am thinking most likely it's compressed/stuck lifters.

You may be onto something with the 180 thought though. I'm not clear on how you confirmed that the rotor was pointing to #1. Plug wire in cap or notch in dist?
-Gypsie2cents

[hercdriver]

Thanks for the reply.

I double checked the fan pulley and the only mark to be found is very small dimple (think ball point pen tip). It is located on the case side of the pulley but is a good 30 degrees to the right of what I think is TDC. I've been using John Muir as a guide to find TDC. If I'm reading him correctly, I need to line up the rotor on the distributor with the #1 plug wire (there is a notch in the distributor that also corresponds with #1). When I turned the engine via the alternator it did take two full fan pulley rotations to equal one distributor rotation (IIRC).

I also considered the push rod had not seated properly, so I did my best to wiggle them until I felt them slide into what feels like a groove. If they weren't seated, that wouldn't explain why the #2 valves seem to have quite a bit of play also.

It feels like I can push(it does take a bit of force) them in about an 1/8" (then they spring back). What struck me most is that I could not get .006 on the gap. The more I would loosen the set screw, the gap had no real change. When I started running out of set screw, I pushed on the push rod side and found it to be much looser than the other valve and a much larger gap than .006". When I release the push rod the clearance goes back to zero.

If understand you, all of this indicates a hydraulic lifter. I do like the idea of trying to pull one of the lifters. I'm just a little reluctant without an able body looking over my shoulder.

As the saying goes a picture is worth a thousand words. Here's about 4,000.

The rotor


Valve top for both #1 and #2


You can see the difference in set screws. The exhaust is out much further.


A close up of the push rod.

[Gypsie]

I double checked the fan pulley and the only mark to be found is very small dimple (think ball point pen tip). It is located on the case side of the pulley but is a good 30 degrees to the right of what I think is TDC. I've been using John Muir as a guide to find TDC. If I'm reading him correctly, I need to line up the rotor on the distributor with the #1 plug wire (there is a notch in the distributor that also corresponds with #1). When I turned the engine via the alternator it did take two full fan pulley rotations to equal one distributor rotation (IIRC).

So, before you started with a valve adjustment the engine ran ok but started to make tapping sounds over the past few months?
Now you want to assure that you are doing a vlave adjustment properly?
The #1 plug wire corresponds to the #1 location on the dist., and the rotor points to this same location but we have no indicator on the fan, (or the indicator is 30 degrees off?

curiouser and curiouser.



I also considered the push rod had not seated properly, so I did my best to wiggle them until I felt them slide into what feels like a groove. If they weren't seated, that wouldn't explain why the #2 valves seem to have quite a bit of play also.

It feels like I can push(it does take a bit of force) them in about an 1/8" (then they spring back). What struck me most is that I could not get .006 on the gap. The more I would loosen the set screw, the gap had no real change. When I started running out of set screw, I pushed on the push rod side and found it to be much looser than the other valve and a much larger gap than .006". When I release the push rod the clearance goes back to zero.


Lets presume you have seated your rods properly. As well, we'll presume that you have hydraulic lifters so you can put your feeler guages away as they will not be needed.

Now set #1 to tdc. (you could try the screwdriver in the hole bit wherein you put a driver or some other stick (that will not leave bits behind; ie wood) down the plug hole when you have it to approximate tdc and move the crank back and forth to the point where the pistion is at actual tdc (middle of the 'glide' point of rotation of the crank)). Be gentle and don't force anything when you have something in the cyl. you should feel it through your tool (no really....)
I still think you can see into the plug hole to see the piston reach top and go past, give a try.

Now, back off your set screw to the point where the rocker has play. assure the rod is seated at both ends. turn srcrew in to reduce play until you have 'just perceptible play' with almost no force on the rod side. wiggle the rocker back and forth to feel the "no force play" (click click click). screw your set screw in to the point where play is gone but there is no pressure on the lifter. You may be able to feel it through the screwdriver if your threads are clean. (i use my fingers to turn the screw in to this point for a more intimate feel of the point of contact....ooooh yeah there your are baby.....). check for "no force play". (no more click click). Go ahead and push it in with a little force to confirm the hydro lifters. You should now be to the beginning of your hydraulic lifter adjustment setting.
now screw the set screw in to your desired setting. Bentley says 2 complete rotations of the set screw. (But many, myself included set to 1 and 1/2 turns in). now tighten the lock nut.

Move to your next cylinder (double check your crank rotation and what cylinder you should be setting by confirming that the rotor is pointing to the cylinder you are about to adjust)
let us know if you notice any difference in resistance against the set screw when you are doing your final 1 1/2 to 2 turns in. This may help understand if you have a stiff lifter (hey hey hey watch it buddy )

If understand you, all of this indicates a hydraulic lifter. I do like the idea of trying to pull one of the lifters. I'm just a little reluctant without an able body looking over my shoulder.
All you have described is pointing to hydros.

Let us know what you find after trying the above.

I am assuming that you did not make changes to the plug wire locations before or after your first attempt to adjust. We are using the previous configuration as a guide post.

[Amskeptic]

the only mark to be found is very small dimple (think ball point pen tip). It is located on the case side of the pulley but is a good 30 degrees to the right of what I think is TDC. I've been using John Muir as a guide to find TDC. If I'm reading him correctly, I need to line up the rotor on the distributor with the #1 plug wire (there is a notch in the distributor that also corresponds with #1).

The timing mark is but a tiny little dimple. TDC (0) on the scale is sort of slanted left.

It feels like I can push(it does take a bit of force) them in about an 1/8" (then they spring back).

The question is can you see the top of the rocker going in, as in, opening the valve? You can overcome the valve spring pretty easily. If the rocker is moving in at the bottom when you push, that is definitely compressing a hydraulic lifter.

What struck me most is that I could not get .006 on the gap. The more I would loosen the set screw, the gap had no real change. When I started running out of set screw, I pushed on the push rod side and found it to be much looser than the other valve and a much larger gap than .006". When I release the push rod the clearance goes back to zero.

This sounds very hydraulic-ish, but you do not have the solid spacers between the rocker arms that we normally find with hydraulic lifters, and your pushrods look to be aluminum. Are they?

You can find that you have no clearance for the .006" feeler blade IF you are accidentally at TDC for #3 instead of #1. To double-check, have someone move the engine with the adjustable wrench on the alternator at TDC #1, and make sure #3 rocker arms move as the engine is rotated back and forth at the TDC mark. You do know that #1 and #3 share the timing mark on the pulley. The distributor will normally tell you which cylinder is actually ready to fire, BUT double-check that when the rotor is above the little mark on the distributor, that the cap is properly indexed and the wire that sits above the spot ACTUALLY goes to #1. Ya never know, you know?
Colin

[Gypsie]

The timing mark is but a tiny little dimple. TDC (0) on the scale is sort of slanted left.
Colin

This is a great point.

One might think that 'top dead center' is speaking to the fan pulley indicator mark being at the "top of the arc" when you are looking at it, when tdc actually refers to tdc of the piston as positioned by the crank.

Do you have a timing scale on your machine?



side note-
I always appreciate when Colin posts these little tidbits (springs and solid spacers and pushrod metal stuff. These little details get tucked away for future use. Thanks CK, yer da bomb!

[hercdriver]

your pushrods look to be aluminum. Are they?
I would say they are aluminum (they are light and have a matte finish). The tips seem to be steel though as they have a polished finish. Would that have any bearing on whether there are hydraulic lifters?

double-check that when the rotor is above the little mark on the distributor, that the cap is properly indexed and the wire that sits above the spot ACTUALLY goes to #1.
I did and the wire does go to the #1 cylinder.

If the rocker is moving in at the bottom when you push, that is definitely compressing a hydraulic lifter.
That is the case. I can press the rocker side with my thumb in about an 1/8".

I am assuming that you did not make changes to the plug wire locations before or after your first attempt to adjust. We are using the previous configuration as a guide post.
I was careful not to turn the cap after removing it.

Now set #1 to tdc. (you could try the screwdriver in the hole bit wherein you put a driver or some other stick (that will not leave bits behind; ie wood) down the plug hole when you have it to approximate tdc and move the crank back and forth to the point where the pistion is at actual tdc (middle of the 'glide' point of rotation of the crank)).
I now have homework for tomorrow. I'll let you know what I find and post a picture of the pulley.

[hercdriver]

OK. I'm back up and running. The bus sounds way better now and I've learned a few things along the way.

I was off on what I thought was TDC. I was close but off by about a 1/4 turn on the fan pulley. I ended up pulling the spark plug out of the #1 cylinder and used a screw driver to feel the piston. The small dimple I had written off as an odd nick came to rest about 20 degrees left of straight up with the piston at the top of it's stroke.

Now that I had that all straight, I went down and rechecked the valves. Still too tight for a feeler gauge and too loose when pressing on the push rod side. At this point I was convince that I have hydraulic lifters.

I cranked the engine over to verify the valves were moving (I had a friend watch as I cranked the engine). Everything looked fine, so I put everything back together and fired the engine back up. Immediately the engine started but with the pinging I set out fix. I asked my buddy if it was the you're about to throw a rod noise and said that it wasn't nearly loud enough for that. With that in mind I took it out for a road test and am happy to report that about 5 minutes into the drive the noise went away. It sounds pretty good actually.

I found what I think is a timing issue, but that is for another thread.

Here's a picture of that dimple on the pulley. Is it normally at the 11 o'clock position for TDC on #1?

[Gypsie]

=D> =D>

Get yerself a timing scale. I haven't seen your response to my question about one so I presume you don't have one.

http://www.busdepot.com/details.jsp?par ... 021119249E

I would guess that the dimple will line up to 0 deg at TDC.

Those lifters just needed to pump up.

Run it around for a bit to assure that they are doing what they oughta and then let it sit overnight. Then do another valve adj. to assure all is well. I am not sure how much was changed during your first adjustment trials.

Nice follow through.

[hercdriver]

=D> =D>

Get yerself a timing scale. I haven't seen your response to my question about one so I presume you don't have one.

http://www.busdepot.com/details.jsp?par ... 021119249E

It's on my wish list.

Thanks for the support,
Dave

[chitwnvw]

I don't think the timing scale can be a wish list item. That's almost like saying oil is on my wish list. If nothing else, figure out how to mark the 28 to 30 btdc, and whatever your idle is supposed to be.

Shoot I might have a beat up plastic one laying around.

[bretski]

Shoot I might have a beat up plastic one laying around.

I definitely do. Hercdriver, you can have it...PM me. Like chitwn said, it ain't a wish list item.

[Gypsie]

I borrowed one from JustGimmeeCoffee and then marked the important measurements on my fan shroud. I need to get one but at this time I have the marks I need to set the timing.

Sounds like you have at tleast one on the way to you.

Do you have a Bentley Manual. There is a nice wish list item if not. You can post questions here and folk will tell you what's in there but it's nice to have one.

[hercdriver]

Shoot I might have a beat up plastic one laying around.

I definitely do. Hercdriver, you can have it...PM me. Like chitwn said, it ain't a wish list item.

Thank you for your generosity! PM on it's way.

Do you have a Bentley Manual. There is a nice wish list item if not. You can post questions here and folk will tell you what's in there but it's nice to have one.

I do have a Bentley Manual. I was surprised that no mention of hydraulic lifters were made in the valve adjustment section (section 5 page 41). I assume they omitted referencing them since they self adjust.

[bretski]

You still need to adjust the hydraulics. Don't be fooled.

Loosen the adjusting nut on the valve you're adjusting. Turn the screw out 1/2 turn at a time, until you get the valve to zero lash (you'll feel an ever-so-slight wiggle). Now pre-load the hydraulic lifter by turning the screw clock-wise 1.5 turns. Move on to the next valve. Lather, rinse, repeat.

You should keep track of any changes in the valves (from that 1.5 turn pre-load) from here on out. This will help you with forensics. If, at the next adjustment, you see less than 1.5 turns to zero lash, that points to lifter wear. More than 1.5 turns suggests valve stretch or seat recession.

PS - I PM'd ya back. Scale is on its way!