The Stovebolt Site Forums The Shop Area Engine Shop serious clanging in motor

Hi all, I was driving along and all of a sudden motor started making a very loud clanging sound. I pulled over turned it off. Started it again and gave it a bit of gas and it started to clang again loud and fast. Suggestions. I'm assuming I am out of commision for the rest of the season. It sounds serious. Remember I am a newbbie. Thanks Rick

I'd start by pulling the valve cover and checking the valve action. Maybe something not so major?

First thing to check see if the flywheel is rubbing something like the cover. Check the harmonic balancer & the front pulleys, water pump, & gen/alt. If the sound is comeing from inside the engine you are right. It could be out of commision for a while. Sometimes something is drawn into the engine if the air cleaner is not on good or something falls out of the carb. It might be a rod knocking.

Hi guys, Ok I took the valve cover off and the shaft that goes through all the (tappets?)that runs from the front to back has snapped at the front, so the first (tappet?) is off. Keepig in mind I'm new to this , I think this is an easier thing to fix rather than down lower. I assume I need to buy a new shaft and to replace i,t I will have to remove the therm housing, rad and grill. Then loosen all the tapets so I can slide the shaft out and in with the new. TIPS ?
Rick

OK just read the manual . I think i remove 6 bolts that hold the rocker arm assembly> The whole thing should lift off. Right? Now I have to get new rod through. I assume I am going to mess up the adjustment sof the rocker arms Right? Any tricks
Thanks Rick

Yes to the six bolts holding them on, and yes to readjusting them.
Here are some shafts on EBAY
One would wonder why the shaft broke. I would look at everything very close. Make sure no valves are stuck.
Also check for wear inside each rocker.
When back together make sure you are getting oiling to the rockers.

Hi Dave thanks for confirming. Do you think if I am careful , after I put the new rod in and put it back together it will be ok to run til warm I understand oil needs to be warm before agjusting. Also what do you do if one of the shafts is stuck. Also ther is an oiling tube in there (Not sure of proper name). It is near the centre of the rod, it seems to have been snipped off. I assume oil should be coming out oof there.
Thanks Rick

The crimp in that tube is normal. It was done to divert more oil to the rocker arms.

Once you get the new rod installed I would remove all the plugs and try to turn the engine by hand at the flywheel before starting. You'll know right away if a valve is stuck.

When you have the rocker assembly removed you can pull the push rods up and check to see if they're bent. They normally bend if a valve gets stuck closed. Keep the rods in order - put the same one back in from where you pulled it out.

You can search "+stuck +valve" on this forum and you'll see others remedies. They usually involve penetrating oil, or giving the valve a whack with a hammer, cushioned with a piece of wood.

This all sounds doable for me. Will try to get the shaft first
Thanks Rick

Before I take this apart I would like to see if there are any bent rods and to make sure oil is coming up.
Can I run the engine briefly with the last rocker removed

Hi Rick,
I would just take the rocker assembly out. It has to come out anyway. You can inspect each push rod at that time. Be sure like Dave mentioned, to label each rod if you remove them, to insure they are returned to the same location.
Unlike later model hollow push rods where oil flows through the rods to oil the lifters, your rods are solid. Oil is pumped into the rocker shaft and is fed to the rockers that way. You'll see all the holes when you disassemble... oh, and I'd wait on the disassembly till you get the new shaft in and are ready to transfer each piece from the old shaft to the new.
I've recently done this... it's not bad.
Dave made a good point too. When you get the rocker assembly back onto the engine, remove the plugs and check your rocker action by spinning the engine. If there's a stuck valve, your engine won't get damaged again. You'd address the valve problem next.
Good luck

I can't think of any reason to do that. What would you accomplish? It's also possible to knock a lifter out of its bore above the camshaft and require further disassembly if the pushrod is removed and the engine is run that way. I'd strongly reccomend removing the cylinder head and getting the valve guides inspected for binding. A valve job now will probably prevent further problems with sticky valves and parts breakage/pushrod bending.
Jerry

Hi Jerry,
I've seen some previous threads concerning rocker shafts breaking. If the cause is from a stuck valve, would this automatically mean the head needs to be pulled? Or is there a nifty trick to get the action back without pulling the head?
(My extremely low budget perspective is showing)
Jerry W.

A valve that sticks tight enough to cause the rocker shaft to break doesn't need any halfway measures. I'm all for doing this type of work once, and getting it right, not doing something halfway and trusting to luck. A couple of hours of labor time and a head gasket isn't all that expensive, and the problem can be assessed much more accurately. A healthy dose of KROIL might solve the problem without pulling the head, but I'd be spooky about the possibility of more trouble unless I got a look at the inside of the valve guide and the condition of the valve stem.
Jerry

Hi all thanks for all the info this is very very helpful. I am waiting for shaft delivery now.. One question. How do I turn the engine manuallly. Is there a special tool that you put down on the lower wheel that the fan belt goes around .. or something like that.

If the fan belt is there sometimes a bit of tension added by pushing on the belt with one hand and a tug on a fan blade with the other works. I have just enough room on the 270 to slip a socket over the Crank bolt, and other times when trying to get things that feel stuck moving I've used a large screw driver or pry bar on the fly wheel from down below and moved it a few teeth in both direction gradually going further each time...

I turn my 54 235 engine by turning the fan, but that's because the rad is out and easy to get to. Before I took it apart I made a short flat bar small enough to fit within the inside diameter of the crank pulley. Then I welded a nut to the center for a socket wrench. To catch the pulley I welded two bolts through the bar that stick out the opposite side of the bar than the nut, and fit into the two holes on the pulley. It doesn't take much pressure on the socket wrench to turn it over that way.

I'm assuming the engine is still in the truck?
I'm not sure why you need to rotate the engine by hand... but another option if you need, is to bump the starter.
Keep us posted on your new rocker shaft installation and progress. We're rootin' fer ya!
Jerry W.

I just recieved the rocker arm shaft. so I will try to get it in in the next week or so. I wanted to crank the motor by hand to see if any of the push rods or valves were stuck (yes/no)
Thanks Rick

Hi all installed the roacker arm shaft last night. It went very smoothly. I ran the engine for about 30 seconds and realised no oil was coming up. I assume I should see oil squirting all over. Is that correct. How long should I run it before oil appears. Rick

?

Within a minute or two.
If you do not see oil then pull the 1/8" pipe plug on the outside center of the head and see if you get oil there. If not pull the center head bolt on the passenger side and see if oil comes out there.
What year engine do you have?

its a 1958 with a 235

should I do this with the motor running or off

Engine running. By 58, they had eliminated the oil line under the pushrod cover and replaced it with internal passageways. They get clogged up pretty often. A quick fix that works sometimes is to remove the center head bolt in line with the pipe plug on the outside of the head, and insert a hardwood dowel rod that's a snug fit in the hole above the threads after filling the hole with oil. Smack the top of the dowel HARD with a BFH, and the hydraulic pressure will clear the passageways of accumulated sludge. If the oil flow is there, but very slow, the same process works with the engine running- - - -just let the hole fill with oil from the pump, and them hit the dowel several times. It won't hurt to run the engine for a while with one head bolt removed.

It's also possible to run an external oil line from the oil pressure port on the driver's side, around the back of the head and tap into the passageway that's plugged at the center of the head. A piece of 3/16" steel brake line works very well for the bypass.
Jerry

I love the idea of the dowel trick to blast out any sludge or debris from the oil passages!
That's what's so cool about this site... it's oozing with experienced wrenchers who have many tricks up their sleeves.
Rick, you might also pull the distributor and use a screwdriver blade (I use a long wood drill bit) in a drill to spin the oil pump. I'd want to insure that it's working before running the engine too much.

Hi thanks for your help.
1. Since I put the rocker arm back on the engine is running quite ruff and wont idle. It ran fine before all this.
2.The oil tube that comes up in the middle of the rockers was pinched tight for some reason (before my time)maybe theres oil down there trying to come up
3. I know I have to do settings where the rocker hits the top of the valve but the manual doesnt give a lot of explanation. I know it has to be hot and I know the measurements but do you take the reading at the high spot or the low spot etc
Thanks Rick

Hi Rick
Not knowing your past engine rebuild experience I would like to mention a few ideas
1)set valves according to firing order 153624-each piston has to be on top dead centre(TDC)-there is a way of knowing that from what is called 'valve rock'
2)good idea to stay with baring the engine by hand, this way you can feel if there is something amiss.
3)check your distributor position in relation to when #1 piston is on TDC

NOTE all engine disassembly should be done with the engine on #1 TDC-it makes for a good baseline to return to

The oil tube is supposed to be pinched. It allows more oil pressure.
For years, my dad and I never had the measuring guages for setting the rockers. We would set them by ear and feel. I bet some experienced guys on here may cringe at my saying that, but that's what we did and it worked well for us.
With the engine running and warm, we would have all the jam nuts loosened to where we could turn the setting screws and would ease the lifter adjustment till it just stopped tapping.
Once the entire line was done, we'd check the response of the engine but throttling the carb. After we were satisfied, we tightened the jam nuts.
I'm glad you got your new rocker shaft. Good job on the assembly of it! You're almost there.
Jerry

Thanks guys, Blanch as for my engine rebuild experience. It is in the negative zone. When I mentioned i wanted to buy the truck my bro said you dont know how to fix them, you dont have the space and you dont have the tools. I said thats what makes it all the more challenging. Besides I just love the old beast.
Now I will have to pinch the oil tube back.
How do I know when which piston is top dead centre and I assume that order 153624 is from the from of the engime moving to the back

Thanks, sorry though I dont understand how to know the cylenders are at the top. I can turn the fan belt to move things very slowly but dont know when cylm is at top. Is it when the valve goes all the way up?

Good for you! I'm thinking you're earning some bro respect

One way you can also check that each piston is up is carefully feeling for the top of it with a screwdriver (plugs removed).

Just another shadetree trick.
Jerry

Hi Rick
just some engine theory here
-the firing order for 6 cyl inline engines is usually 153624
-the following cyl are paired
#1,#6
#2,#5
#3,#4
this means that #1 and #6 come up to TDC at the same time but they are on different strokes, hopefully #1 is on compression, #6 is on exhaust stroke, what determines that is
#1 both valves are closed, #6 the exhaust valve is open and starting to close while the intake valve is starting to open for the intake stroke, at this point it is called ‘valve rock’
-so you would watch #6 valves to see the opening and closing and this tells you that #1 is on the compression stroke. Now if you don’t have the rocker shaft installed you would install the #6 cyl push rods and observe their movements.
This has to be done for each cylinder for setting the valves, so for #6 you would watch #1 for valve rock and so on for each cylinder and its appropriate partner.
You could stick a screw driver down #1 spark plug hole but you want to be sure you are on the compression stroke of that cylinder, ‘valve rock’ is a more scientific approach.
I hope this doesn’t sound confusing but let me know how it goes.
My background is a licensed diesel mechanic and I know that this is the way its done to set valves and injectors depending on the manufacturer.

Hi Rick(not sure if this maybe a duplicate message)
just some engine theory here
-the firing order for 6 cyl inline engines is usually 153624
-the following cyl are paired
#1,#6
#2,#5
#3,#4
this means that #1 and #6 come up to TDC at the same time but they are on different strokes, hopefully #1 is on compression. #6 is on exhaust stroke, what determines that is
#1 both valves are closed, #6 the exhaust valve is open and starting to close while the intake valve is starting to open for the intake stroke, at this point it is called ‘valve rock’
-so you would watch #6 valves to see the opening and closing and this tells you that #1 is on the compression stroke. Now if you don’t have the rocker shaft installed you would install the #6 cyl push rods and observe their movements.
This has to be done for each cylinder for setting the valves, so for #6 you would watch #1 for valve rock and so on for each cylinder and its appropriate partner.
You could stick a screw driver down #1 spark plug hole but you want to be sure you are on the compression stroke of that cylinder, ‘valve rock’ is a more scientific approach.
I hope this doesn’t sound confusing but let me know how it goes.
My background is a licensed diesel mechanic and I know that this is the way its done to set valves and injectors depending on the manufacturer.

Hi Rick(having trouble submitting this)
just some engine theory here
-the firing order for 6 cyl inline engines is usually 153624
-the following cyl are paired
#1,#6
#2,#5
#3,#4
this means that #1 and #6 come up to TDC at the same time but they are on different strokes, hopefully #1 is on compression. #6 is on exhaust stroke, what determines that is
#1 both valves are closed, #6 the exhaust valve is open and starting to close while the intake valve is starting to open for the intake stroke, at this point it is called ‘valve rock’
-so you would watch #6 valves to see the opening and closing and this tells you that #1 is on the compression stroke. Now if you don’t have the rocker shaft installed you would install the #6 cyl push rods and observe their movements.
This has to be done for each cylinder for setting the valves, so for #6 you would watch #1 for valve rock and so on for each cylinder and its appropriate partner.
You could stick a screw driver down #1 spark plug hole but you want to be sure you are on the compression stroke of that cylinder, ‘valve rock’ is a more scientific approach.
I hope this doesn’t sound confusing but let me know how it goes.
My background is a licensed diesel mechanic and I know that this is the way its done to set valves and injectors depending on the manufacturer.

Hi Blanch 53, I see 3 replies from you but they seem to be blank or am I missing something

Click the ...Quick Quote... button under his blank post
You might be able to,see his response in the preview window

Another way to tell when the piston is at the top is to use a wooden dowel about 10"-12" long that will fit into the spark plug hole and rest on the top of the piston. Rotate the engine by hand until the dowel rod comes all the way up and just as it starts to go back down you know that the piston is at the top. Basically the same as Hellomrwilson said using the screwdriver trick.

Hi Rick (having some difficulty with getting my message submitted)

just some engine theory here
-the firing order for 6 cyl inline engines is usually 153624
-the following cyl are paired
#1,#6
#2,#5
#3,#4
this means that #1 and #6 come up to TDC at the same time but they are on different strokes, hopefully #1 is on compression. #6 is on exhaust stroke, what determines that is
#1 both valves are closed, #6 the exhaust valve is open and starting to close while the intake valve is starting to open for the intake stroke, at this point it is called ‘valve rock’
-so you would watch #6 valves to see the opening and closing and this tells you that #1 is on the compression stroke. Now if you don’t have the rocker shaft installed you would install the #6 cyl push rods and observe their movements.
This has to be done for each cylinder for setting the valves, so for #6 you would watch #1 for valve rock and so on for each cylinder and its appropriate partner.
You could stick a screw driver down #1 spark plug hole but you want to be sure you are on the compression stroke of that cylinder, ‘valve rock’ is a more scientific approach.
I hope this doesn’t sound confusing but let me know how it goes.
My background is a licensed diesel mechanic and I know that this is the way its done to set valves and injectors depending on the manufacturer.