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Valve noise

G

GDR72

Gold Level Sponsor
Hi, so i recently was listening to my 1725 cc series V 1967 Alpine engine and I heard what I consider to be noisy valve clatter.
I took out my stethoscope and found that the noise was in the top of the engine, and in thefront of the engine. At idle, I can hear what sounds like 1 loose valve with possibly excessive clearance.
I removed the valve cover after a proper warm up and checked and adjusted my valves and I really didn't find any particular valve that would have made that amount of noise.
At idle, its a steady noise, when I rev the engine to 2000 rpm, (Blip it) it seems the noise goes away but upon returning to idle, it continues.
At first, i was trhinking valve clearance, but thats good. There is no excessive rocker shaft play, it is definitely up top, But now I'm thinking, Timing gear? aka, cam to crank gear?
Any thought's??
PS, I realize that a solid lifter engine has valve lash clatter. This is something more.
 
If the rocker arms have worn tips that contact the valve stem, one will never get a good valve lash with a feeler gauge. It will feel tight, but it will be too loose from the wear patterns. You could double check your valve lash with a dial indicator.
There are other areas that I can mention that can make noise.
Jan
 
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Did you check the rockers whether the bores are really free and delivering oil ? Check during running with valve cover off. Use a small needle to poke the oil holes free. Seeing a lot of engines with fully or partially blocked rocker oil bores recently...
 
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Any chance you could post a video with sound so we can hear and see what you hear and see?
 
If it goes away as you increase the RPMs, it’s unlikely to be a valve lash issue. Those usually continue to make noise as you increase the RPMs. As such, the sound must be coming from something else. It is possible that it’s a rattling timing chain. It also could be a bad bearing in the water pump. Diagnosis of both of these can be made by using a mechanic’s stethoscope or even just a stout screwdriver held close to the ear (being very careful of rotating components).

And although somewhat more rare, it’s also possible that it’s piston slap, as this is usually only noticeable at idle, and becomes less noticeable as RPMs increase. I’ve heard this from time to time, and the best way to diagnose it is to disconnect the spark plugs while at idle, one by one, and see if it goes away. If it does, it’s almost certainly piston slap on that cylinder.
 
Thanks to all for your reply's and thoughts.
I am going to remove the rocker shaft AFTER I confirm the oiling situation.
I will also be looking in to timing chain noise and piston slap as a possibility.
Will post more later.
Thanks again from the frozen North!!!
 
When you take off your shafts, it's recommended to check the rocker profiles carefully. No flats or recesses should be visible on the surfaces where they touch the valve tips...
 
Flat feeler gauges don't work so well on worn rockers ... Try a pin gauge for adjustment or an appropriate size drill rod.

..... David
 
Correct, David - good suggestions. I’ve also used wire gauges ordinarily used for setting spark plugs. But my most accurate setup is a dial indicator on a stand, but it needs to be accurately placed on the rocker.
 
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