The Stovebolt Site Forums The Shop Area Engine Shop Valve problem - about to get in over my head...

The intake valve on #1 is making a bad noise. When the engine is turning at starter speed, the sound is a lot like a loud click like a large electrical relay would make. (I'm not using the starter to turn it anmore...) When I turn it by hand, just as the pushrod starts to come up and actuate the rocker arm to push down on the valve, is when I can hear something down in or under the head. The noise lasts all the way through the down/up action of the rocker arm. I'm no good at describing noises, but its something between a clank and a rattle. If I go slow enough there is no noise, but just a little bit faster than that, it's audible. I can also feel it with my hands on the pulley turning the crank.

So, I know I've got to get into the top end to find whats bent, broken, or sticking. I've pulled engines out, and put them back in before, but this is going the be the first one I'm digging down into, since I helped my dad rebuild one 30 years ago when I was 15...

So, here's my question... do I need to take off the rocker arms assembly, and pull out all the pushrods, before I loosen the head and try to lift it off, right? Or do I leave the rockers/valve springs, head assembled, and just very carefully lift it high and clear of the pushrods? They arent going to lift with the head are they?

Thanks for any tips!

Keith

Before I would do anything, I would squirt something like Marvel Mystery oil into the cylinder and let it work for about a week. You may well have an intake valve full of varnish and the oil will dissolve it. You can loosen the the valve adjustment and move the rocker to the side and pull the pushrod, but you have to be careful. Sometimes the pushrod sticks to the lifter and pulls it out of the hole. Then you have to take the side cover off. If you turn the engine to where there is clearance on the valve, you can spin the pushrod and look down in the hole with a light and see if it is bent

I've already got the side cover off. In fact there are no fenders on that side of the engine so I've got very good access and plenty of room. It sure sounds more like something is hitting, but if disolving some varnish will clear it up, then I'm all for it. Do I just squirt the oil in from the spark plug hole, or do I run some down from the top of the valve stem, too?

Ken, I'm gonna send you a PM about that haul you are making to Minnesota and back...

Keith

Frist thing is get a shop manual it has complete instructions on taking the head off and reinstalling it and You will need it to reassemble the rockers ,I would pull the head it's not that hard and than take the valve out and see whats going on for a few hours work you could have a more dependable engine ,yes you need to remove the rockers than remove the pushrods than all the head bolts than you can lift the head off , do you have the intake and exhaust off ? If thats not done than thats all got to be removed to just take you're time ,But get a shop manual if you can'nt get one they are on the web at Old car and truck project I believe and you could print out the pages you'll need.

Pete

Before pulling the head, lets check a few items.

First, rotate engine till any intake valve, other then the bad one, is at full open position. Measure somewhere on the head to the top of the spring to get an idea how far its open. Do this for a few of them to see how they compare to the noisy one.

If the noisy valve is not lifting all the way, then check to see if the pushrod is moving as far as the others using the same idea as above. If you determine the lift is OK, then check to see if the valve is returning to the same height as the others.

If the lift is not correct, then the camshaft or a lifter could be bad. By pulling the offending pushrod out, you should be able to get the lifter out and check the face for wear.

Use a steel rule or a indicator if you have one for the measurements. If its a obvious problem, you will see it by these few checks.

Don't forget, the fuel pump is run off the camshaft and could be making noisy at the sametime the valve is opening. It might be worth your time to remove it before the head.

Joe

Leading up to this, I had just cleaned/refurbished the fuel pump, and suspected (hoped) that the fuel pump actuator on the cam was making the noise... So the fuel pump was the first thing that came off while I was searching for the noise. Then the valve cover... Then the oil pan... Then the side cover over the push rods...

Visually, the rise and fall of the bad one relative to the others looked the same to me... It didnt occur to me to measure them more methodically and look for a variance to small to see visually. I have been worried about this being a problem on the cam, though. Been hoping for a helping hand with more muscle than my 10 year old son to come turn the pulley on the crank slowly while I reached in through the fuel pump hole to feel the cam surface that drives that pushrod... or just to watch it from underneath if I can get a clear view, since the oil pan is off.

I skimmed through the online one on Saturday... It's easy to not find what you're looking for in those online manuals... I need to page through it more carefully/completely this time, and one of these days just spend the time to print the whole thing out... Since they are not searchable, flipping through real pages is the next best thing...

If the head is still on, take a pry bar or large screw driver and get under the rocker arm and move the valve up and down. The stock springs are pretty weak, so you shouldn't have much problem moving the valve.

Joe

Did'nt get a chance to get out there and get dirty or measure the open height vs the closed height across the other intake valves. But I did manually move the rocker arm/valve down/up this weekend. I dont know if I got the full travel when I did it. But moving just the valve/spring/rocker, (leaving the pushrod down) did not reproduce the noise.

The shop manual says "insufficient valve to guide clearance will result in noisy and sticky functioning of the valve and disturb engine smoothness of operation"

Replacing a valve guide sounds like a machine shop operation for reseating the valve? The test of measuring the open/closed height relative to the other valves, will that show the valve spring sitting higher than the others, if there is excess valve to guide clearance? Since I'm pretty sure I still have compression in this cylinder (the crank is much harder to turn by hand when the spark plugs or the compression guage is in... ) I dont think "excess clearance from the valve to the guide" is going to show up in the height of the valve spring relative to the others. I need to read through the shop manual a few more times, though, cuz I didnt ~get~ how to measure the valve to guide clearance...

Keith

Valve clearance is measured with a feeler gauge between the rocker arm and the tip of the valve. However, you must inspect the tips of the rockers to make sure that there is no groove worn in them which gives you a false reading. I have replaced a lot of valve guides with a hydraulic press. However there is always a risk of cracking a head if a guide does not yield soon enough. Most people these days prefer to have the guides reamed out and a sleeve installed. I have a 50 year old Sioux valve machine for refacing valves and then grinding the tips an equal amount as removed from the face. It also has a rocker arm attachment. I use an old fashioned stone type grinder for the seats, but I measure them with a runout gauge. But this is really machine shop work. The term sticking valve means that varnish has accumulated on the stem and does not allow the valve to travel freely. It is usually caused by stale gas. Measuring guides is rather simple, but it takes a valve compression tool to remove the valves, a mike to measure the valve stem and a small hole gauge to check the guide and check it for being bell shaped. This is probably more than you want to do. I still think you should remove the spark plugs, squirt some Marvel Mystery oil in each cylinder, let it set for a week and then turn it over and see what happens.

Just loosen or remove that adjusting bolt on the rocker and if the noise goes away it's that valve or rocker arm ,if not it's a good idea like crenwelge said to squirt alittle Marvel in there and see what happens, was the engine running before this or was it setting for some time?

Pete

Max, The noise you've described doesn't sound like any valve related noise I've ever experienced.I think you're going to find a more major problem giving a noise in relation to the valve movement described but, I hear you say the pan is off , take an extra look at the big end bearings.You say the click can be felt in the crank/pulley--observe the big ends when this click happens for unneeded clearance.Tap the big end side to side on the journal looking for differences in tightness- a bearing in deep trouble at one stage actually wll be too tight as the thinned out bearing shell climbs up on itself-the end is near when this happens.Look for signs of more heat on one rod than the others caused by the failing bearing tightening up and cutting off the oil supply.Look in the oil pan residue for material thrown from a failing bearing in line with the "throw off".
Also be suspicious of the piston pin area when this click is heard-these old pistons come apart in the strangest ways and many times get noisy when the piston is in a certain position.I once witnessed a cast iron piston in a 216 that perfectly broke off the piston head at the bottom ring groove--when the head was removed, all cylinders looked normal but the piston in the bad one didn't go up and down the detached piston head just stayed on TC.
If a valve were this tight in the guide it would probably would bend a pushrod and you would have found that.
Good luck

A quick test of a valve guide is to grab the valve spring and try and move side to side, if its loose you will feel it. With the weak valve springs, you might also try and twist it while holding down on it. I'm not sure you will get this done, but you might be able to.

A sticking valve sounds like a high pitched sqeaking till it locks up all the way!

Sounds like the next step is to remove all the rockers and turn the motot over to check for noisy.

Joe

Bought the truck last October. PO reported the engine/transmission to be rebuilt and running until the 12v battery on the 6v system did the expected. Visually, the engine looked clean enough on the outside, it was a plausible story, but I didnt take the PO's word as a bond... I figgered I had a 50/50 chance on what was true and not true that he was telling me... The price I paid reflected the things I could see on the surface. Pictures of this truck/engine are at the gallery and fotobucket links below. I dont have pix yet of the inside of the engine now that I can see it. But the top end (rocker assembly) is definitely not as recently re-furbished as the outside skin of the engine... From the bottom, the crank, piston rods, etc, dont look ugly at all, the the condition is pretty clean, and the color is dark golden, but definitely not black. Strained the oil after draining it, and it was clean. Although it had turned pretty black, despite being very clean/fresh oil before we started the engine.
Fresh in terms of the engine not run since the oil was put it... It actuall could have been old because I have no idea how long that clean oil was in there before I got the truck. Looking back, I should have changed the oil so that I knew it was fresh good quality oil...

In May we were ready to try to start it. The engine turned smoothly and quietly by hand, had compression, very clean oil... So I chose to see if/how it ran without taking it apart.
Had no real problems, and once I educated myself on the wiring and timing, it was running. It sounded very nice, ran very smooth once I adjusted the distibutor position... I didnt set the timing with a light, I just set it by ear. It ran easily, and I was amazed how low I could set the idle and it would still run. I didnt keep the idle that low, because the alternator wouldnt even charge, and the oil pressure was too low. It had 20 to 25 pounds oil pressure and the alternator was charging where I did set the idle. I dont have a tac, so I dont know what RPM that was, but it was a comfortable idle by my ear. When I would gun it, oil pressure would raise up to 30. Water temp would get up to about 140 and hold steady when idling.

At that point, the only problem was that every now and then I thought I heard a noise that sounded like the fins of the alternater pulley fan hitting the mounting bracket... That wasnt happenning, but that is what the sound made me look for.

It sort of sounded like it was coming from the balancer, maybe. But, I had no exhaust system yet. Just the 4 into 1 stock header, so there was a good bit of noise under the hood, and I wanst sure that the noise I was hearing might be an echo coming out of the header.

It ran good for a few weeks. Then one day, it wouldnt, and it turned out to be the fuel pump. The lower end of the bladder was full of gunk and debris. Cleaned it out, ran great again. The next week, the same problem. This time it occured to me that the bad-gas smell kept coming back each time I got into the fuel pump. So, I decided that my gas tank must be worse than I thought. I cleaned/rinsed it out real good, but did not acid-bath or seal it... I just put a good sock on the inlet hose, and inline fuel filter before the pump, and an inline filter before the carb. So I dont think I was getting and debris in the fuel, but I think the fuel was spoiling even though it was only a few weeks old. So I put a 5 gallon gas can in the bed, and ran the fuel line there, cleaned the fuel pump, and it started ran nice again. For 1 day. The next day, when trying to start it, is when this bad problem started. While cranking, the loud "click" would happen, and it didnt start eagerly like usual, and even gave a little backfire. It seemed like I may still have fuel pressure issue and or a timing/ignition issue too, but with the mechanical sounding problem in the rotation process, I did not want to solve the other issues and break something worse. So, here we are.

I agree, it doesnt sound like any valve issue I've hear heard, and I've been worried about a deep bearing problem ever since... that's why the pan is off...

The only correlation to the #1 intake valve is that the noise doesnt happen on every rotation of the crank based on the piston position, it's every 2 rotations of the crank synchronized with the intake stroke. So, I assumed cam in connection with the intake valve, or something in the valve mechanics itself... But I'm gonna reread your post over and over until I understand it, and see if I can perform some of those dianostics....

Let me extend my thoughts based on the reported testing already done.
Consider a problem in the cam drive; broken gear tooth, a particle lodged in the teeth (would have to be the cam gear not crank gear based on frequency),bolt backing out of the cam retainer plate and contacting the gear,or sumpin wierd we aint seen before.
Thanks for keeping us posted.

I considered pulling the front/timing cover off before the head, to try to find the problem... havent ruled it out being a cam drive gear... Decided to rule something related to the head, or that I would be able to see once the head was off, since rotation of the distributor didnt seem to be slipping... I presume if a tooth on the cam gear has broken off, that I'd see that as a pause in the rotaion of the distributor?

I've got a lot to do to figger this out, that's clear. Should get some time this weekend to get at least some answers...

Thanks everybody!

Keith

Max, you speak of old gas, and you say the noise is on every other rotation. That is a classic symptom of stale gas an varnish on an intake valve. I would recommend you squirt some Marvel Mystery oil in each cylinder and let it set a week. Then try turning it over with no spark plugs and see if you still have the noise. If not I would put gas in a small container and suspend it over the carburetor to bypass the fuel tank, lines and pump. I have an aluminum go kart tank that works good for this. If you suspend it about 18" over the carb, you get about the the correct fuel pressure. I would sure recommend this before you start taking things apart that you may never get back together again.

You can also buy a very cheap tool:

http://www.jula.se/stetoskop-for-motorer-129809

Sorry, the site is in Sweden, but the picure shows the tool anyway.

This helps you to really locate WHERE the sound comes from.

I seem to remember people referring to an interference problem between the connecting rods and camshaft lobes if there's a slight out-of-time problem on the cam. I've never experienced it myself, but I've heard it referred to several times since I've been a member of this site. Now that you have the oil pan off, start looking for a connecting rod/cam lobe contact point when you get into the neighborhood of the position whete the noise happens. Also, if a part of a tooth on that fiber timing gear has broken off, it could have jammed into the gullet of the tooth and created a tight spot when that set of teeth mesh. Definitely take the timing cover off and inspect the gears!
Jerry

Ken, I'm gonna definitely repeat this advice to myself every step of the way...
And I will put the oil in and start the soaking as soon as I have time to pick some up, hopefully today.

I'm just not sure I have the patience to wait a week without doing something... On top of that, I'm at the point I really want to see this noise... As much as I want it to be varnish that will disolve and be gone with a magic cure, the sound and vibration that occurs really seems to have more to it than that... I even freed up the top of the push rod so I could actuate the rocker/valve manually, and no noise when just the valve moves. The noise still happens though when the cam/crank/pistons move without the valve...



That sounds like something I will be able to spot, without taking anything more apart, and it explains all the facts...

Thanks again every body!

Keith

I'd pull the timing cover and check the gears.

What about the cam retainer plate and screws? One of the screws could be backing out, or both letting the cam walk forward which could inturn let the rods or lifters hit the cam lobes in a odd way.

I would remove all cam driven pieces, lifters, distributor, and fuel pump, then go hunting for the noisy.

Joe

Marvel Mystery oil is not some kind of magic cure. It has been around for over 50 years and there are many other upper cylinder lubricants that do the same thing. And they work. Last April I tried starting a compressor and flooded it. It sat until a couple of weeks ago, and the intake valve was stuck so tight the engine would only turn 1 3/4 rounds either way. I put in Marvel and tried it every day and I think it was the 5th day or so, it turned over like a new one. I have done this to many engines, and I'm sure the guys on this forum who have been working on engines for 50 years have done the same thing. I would not have the patience to put things back together if I took more apart than needed. It may be something else, but I sure wouldn't take things apart before I eliminated the simple things. Marvel mystery oil will also dissolve carbon in your ring groves and help your engine with better compression and oil control.

It sound like he already has it apart.

Ken, I picked up the MMO on my way home today, so putting that in is going to be next... sorry about the choice of the word magic... I was reffering to the sinking feeling I have that the connecting rod is hitting the cam lobe, and that cleaning the varnish and carbon will be great, but wont fix my engine if my cam has slipped.

Builder, I dont have anything nasty taken apart yet... rocker arm cover, and oil pan, and fuel pump is off, nothing else yet.

I'll confirm if I have a cam/rod interference issue before I pull the front end off to look at the timing chain and gears.

And if I cant find a cam or bearing issue from the bottom, then I may take the rocker arm off, take all valve/tappet/lifter movement out of the equation (without getting into a complicated dissasembly) and see if the noise still occurs...

That will give the MMO at least a few days or more to soak.

I'm going to squirt it into the cylinders through the spark plug holes. Is that right? A couple ounces in each cylinder? Will it wick it's way up to the valves?

Give the tops of the valve guides a generous soaking as well, by squirting the penetrating oil through the springs at the tops of the guides. It will crawl down the valve stem a lot better than it can wick upward.
Jerry

Ken Crenweldge get's the prize for the advice about Marvel Mystery Oil and ruling out simple things before taking things apart that I may never get put back together.

The furthest I took things apart was to lift off the rocker arm assembly. The crank and pistons turned very smoothly and silently when there was no rocker arm pressure or cylinder compression, so I was able to rule out interference between the cam and connecting rods. And the cam was still in perfect position to have #1 at TDC with respect to the timing ball in the flywheel, and the cam had no play at all so I was able to rule out any timing chain/timing gear issues.

While the rocker arm assmbly was off, I cleaned out all the oil passages... I reinstalled the rocker arm assembly (forgot to reapply fresh lube/oil after cleaning it) and then when I turned everything by hand, I had the same noise back, but this time in about 5 or 6 places... It was a noisy rocker arm all along... My conclusion is that I wasnt getting oil pumped through all of the rocker arm assebly passages, and I had a rocker arm getting dry...

The cylinders soaked in MMO for a good 2 or 3 weeks, as did the rocker arms/assembly. Filled the crankcase with some Mobil 5000 5w30 mixed with MMO, to get some good low viscosity lubication flowing through to try and give the oil passages a real good cleaning.

Got it fired up again finaly yesterday. It ran very rough for a while, and then eventually cleared up and ran much better. I think it was the burning out of the MMO in the cylinders that was bogging it down. Also the carb had a fuel/MMO mix soaking in it for a while... probably too rich on the MMO. Hoping to add some octane boost and fuel treatment to the gas and start her up and let her run for a good long run today. Maybe even get a short drive or two around the block... If good gas and 20 or 30 minutes of running doesnt get her running nice and sharp, then I'll get under the dizzy cap and make sure the rotor and points are clean and well adjusted...

Only minor stuff, either way. I took a good look around inside the crank case, and feel very good about the lower half of this engine. And on the top half, I think it has new valves and well machined valve seats... and when the PO got the block/head back from the machine shop, I think they just reinstalled the rocker arm assembly without cleaning it at all.

I'll take the valve cover off while its running today, and make sure there is good oil flow everywhere it should be ....