Loose valve guide

junkyardjeff · April 13, 2011, 10:29:12 PM

Will a loose valve guide sound like a valve that needs adjusting,I have been chasing a top end rattle in a 57 chevy 235 that I have in my 37. Yesterday I installed another set of rocker arms that I filed down the worn tips and adjusted the valves while the motor was running and it got rid of the tap it always had so I drove it to a cruise in tonight and the rattle is still there,I noticed it does not make the noise when cold and will start when it warms up slightly. The reason I am thinking loose valve guide is I think I had all of replaced when I rebuilt the motor and maybe one loosened up,if its not a guide it has to be a weak valve spring or could a wrist pin make a rattle.

wayne petty · April 14, 2011, 04:23:28 AM

i have a question jeff..

did you get the engine with the head ON or off?

?

i have run into this model motors.. where the pistons were a little too tall...

the piston would smack the head just slightly.. really made some noise when the engine got hot and the connecting rod and piston stretched with the heat...

do you have various sizes of wire... where you might bend some into this shape...__/ sticking it through the spark plug opening and seeing how much clearance there is between the top of the piston at TDC and the cylinder head...

the last 216 that got done in the repair shop... needed to go back to have the tops of the pistons turned down slightly..

got a friend with a bore scope. or camera on a probe... stick it through the spark plug openings.. look at the top of the pistons...

i am taking that you have an automotive stethoscope..

junkyardjeff · April 14, 2011, 08:24:18 AM

The motor was togather when I got it and I think the block was decked and align bored plus the rods reconditioned,one cylinder had a crack and was sleeved. I dont remember the motor making this noise right after I put it togather but will rattle just before I shift and after I am in high will rattle when thyere is no load on the motor,I only noticed it a couple years ago.

wayne petty · April 14, 2011, 10:18:54 AM

without hearing it.... have you had a chance to toss in a bottle of octane booster to make sure its not detonation/preignition...

been able to check the maximum amount of timing...

decking the block... align boring the mains both move the pistons deck heights up slightly..

stick a probe light through the spark plug holes with the pistons down just a little bit... see if there are any marks on the top... the valves can also impact the top of the pistons ...

junkyardjeff · April 14, 2011, 06:51:55 PM

Noise goes away with #2 plug wire off,wrist pin or rod bearing?.

wayne petty · April 14, 2011, 10:12:41 PM

got a section of 1/4" wooden dowel...

perhaps... 3/8 or even 1/2... where you could position the number 2 cylinder about half way down... gently resting ones hand on the wooden dowel.. while somebody else rocks the crank back and forth just a fraction...

shim the socket tight with several layers of plastic bag...

tighten up the breaker bar swivel nut.. so the mechanical link it instant...

you might even be able to feel any slack by rocking the crank back and forth..

why the wood dowel.... so you can have the friend move the crank downward.. you will be able to feel the piston. if it moves instantly.. or a fraction of a degree later...

you might have to have the breaker bar up where you can get a hand on it.. and the other on the wooden dowel... another good reason to use plastic bags over the crank bolt to tighten the fit of the socket...

that is.. if there is a crank bolt on that motor...

years ago... when i worked at the engine rebuilder.. we had a 228 stovebolt firetruck motor in.. and a toyota land cruiser F motor.. they were almost the same.. except for metric threading.. and a what looked to be a better designed lube system on the toyota motor...

i wonder.. how many people have stuck a properly modified toyota motor into their early chevy pickup or cars....

junkyardjeff · April 14, 2011, 10:39:56 PM

No bolt on the crank so I cant do that,thinking about finding another motor to drop in it and eventually tear it down and see what happened. Its been making that noise for 3 years and I thought it was valvetrain since its more like a rattle then a knock, and I dont think putting another bearing in will help now,I cant remember how much was taken off the crank and I would need to get someone who is better reading the mics to check it for me but for now its getting heavier oil and drive it locally.

junkyardjeff · April 14, 2011, 11:13:01 PM

I just thought of something,I think the #2 cylinder is the one that got sleeved due to a crack.

junkyardjeff · April 23, 2011, 02:41:38 PM

The valve spring on the exhaust valve on #2 was very weak and was the cause for most of the noise,the others are not too far behind so I will order 10 more springs and replace them all. From now on all motors I rebuild will get new valve springs.

bowtietillidie · April 23, 2011, 08:59:11 PM

I have watched this topic closely because the Chevy Inline 6 is my second favorite motor . Here is how I deal with possible Valve problems. I Get your Vacuum gauge and it's directions read them They will tell you how to check for worn Valve guides . Need more proof a sound engine will have AC 44's or 45's if they have an S at the end of the plug number suspect internal problems such as Valve guides or rings . I won't go into piston ring checks. On with valve checks . Next pull the valve cover bring each piston to TDC on compression stroke . On each cylinder ON COMPRESSION STROKE Grab first an intake valve with your thumb and index finger and try to rotate . If you can rotate that spring it needs changed . You can try to change the spring with the cylinder on TDC compression This may not work out because those Old Chevy Valve keepers grabbed the valve pretty hard. I am guessing every one knows about changing valve springs using compressed air thru the spark plug hole. If the air trick does not work the head must come off . Disassemble the head very carefully . Take six Exhaust Valve springs and line like they came off the head then do the same with the intake valve springs. Now find something Flat ( 2" flat bar 16 inches long 1/4 thick) using your new straight edge gauge your In and Ex springs. HMMMMMMMMMM look at all Them thar MUTT and JEFF valve springs ( short and long) Valve springs need replaced Now we can go back to the head . With the head laying on it's side start at one end....... Push a valve shut then with the other hand try to wiggle the valve side ways NOT UP AND DOWN. If you feel any movement it's valve guide replacement time. See your friendly machinest ........ BRING large amounts of MONEY :!: :cry:

junkyardjeff · April 23, 2011, 09:09:01 PM

If I can remember correctly I had all the guides replaced when I rebuilt the motor and should be still good with less the 10,000 miles,I ordered 10 more springs and they will all be replaced. From now on I will replace all valve springs when rebuilding a motor.

enjenjo · April 23, 2011, 10:20:07 PM

You can also hold the valves up with a piece of rope. Three or four ft of clothesline rope though the spark plug hole, and crank the piston up against the rope.

junkyardjeff · April 24, 2011, 12:08:45 AM

I have the fittings to put air in the cylinder.

junkyardjeff · April 26, 2011, 10:24:04 PM

Just got done installing the other springs and all the noise it makes is the normal clatter of the solid lifters and cant wait to take it for a spin if it would quit raining.

Rrumbler · April 27, 2011, 10:43:24 AM

Ahhh, mem'ries.

I just read this thread (don't know how I missed it early on) and smiled. Seems you have found the problem and the solution, so, if I may, I'm gonna tell you my experience - for what ever it's worth.

My first '57 Chevy had a six in it, and it was a pretty good runner for a Stovebolt; I almost literally ran the wheels off of that poor thing, putting over 100k on it in just over two years. Somewhere in the early times of our life together, it started to "tick" when it got warm, then the tick turned into a "peck", and one day in a small "town" a long way from home and familiar digs, I think it was Gila Bend or maybe Casa Grande, Arizona, it started running real bad, and heating up, and I just barely limped into one of those old service stations you often see in movies: old run down buildings, a couple of gas pumps out front under a canopy, lots of dirt and scrub all around, a wrecking yard out back, and the old tow truck sitting beside the garage bays; was summer, 1962. I pulled up by the side of the garage, and shut it down and went inside. A man was working on a truck inside the garage, so I didn't bother him, just got a cold coke from the ice box (hand written sign on the box said "ten cents", and there was a jar on the shelf with a few dimes and nickels in it), dug out a dime and put it in the jar, and stood in the shade and lit up a smoke. Pretty soon, the guy crawled out from under the truck, wiped his hands, and got a coke and stood by me and lit one up, too; he was the quintessential old small town mechanic: dirty coveralls, greasy oil company skull cap - Pennzoil or Quaker State, it seems, and generally rough around the edges. He said "sounds like you might have a busted valve spring in that Stovebolt." I said something to the effect that I didn't know, and it didn't matter because I didn't have enough money to get it fixed so I was probably going to have to get back to base in San Diego on my thumb, and take care of the car however I could. He told me I looked like I wasn't afraid of a little work, so if I wanted, I could stick around and do some stuff while he finished the clutch in the truck, and by that time the car would be cool enough to take a good look at, and he'd see if he could help me out; I said sure, and he pointed me to a broom and a brush and dust pan and flat shovel and said the wind had gotten a lot of dirt blown in and I could start by sweeping the place up. Well, long story a bit shorter, it was the exhaust spring on #6, and he showed me the rope-through-the-spark plug-hole trick, how to make a handy spring compressor for a Chevy six (as well as others) out of some odds and ends, and we got it fixed and me on my way. He wouldn't take any of what little money I had, said I could pass it on down the line, and maybe someday help out someone who needed it. Of course, I picked up a few valve springs and an extra retainer or two and some keepers, and made up a compressor, and got some quarter inch cotton line, and put it all in a box in the trunk with my toolbox and stuff; I already had extra spark plugs, distributor cap, rotor, condenser and points, and a bunch of other stuff that I thought I needed, and the valve stuff just added to the kit. I went through several more valve springs before I traded the car off, and got to where if I wanted to burn my hands doing it, I could get one changed in about fifteen minutes; usually waited for the engine to cool, though.

Don't ya just love war stories?