Clacking sound.

[Tony S,Fl.]

A fellow joined our club yesterday and wanted a opinion on his engine. 28 tudor . Parking brake on left side. At idle it clacks. not knock but clatty clack. Sounds like its coming from #1 or 2 cylinder area. Loose valve seat or broken valve spring ? At speed it's quiet other than a clack now and then. At idle clack clack clack.Gas tank wouldn't flow till we put compressed air through the line from carburetor to tank.We know how to clean the crap out. Just wondering about the duck in the engine. Thanks Tony

[G Baese]

Tony-
1f, at idle it quacks. Not a knock but quackity quack. Sounds like its coming from #1 or 2 cylinder area... At speed it's quite, other than a quack now and then, and at idle quack quack quack, and you are just wondering about the duck in the engine.

Check to see if the exhaust manifold gasket is quacking around #1 and 2. if not, remove the valve chamber cover and look inside for evidence of a quack, and if that doesn't reveal anything, taking the head off is the best way to get the duck out.
TIC, and Good luck,
gb

[bikejunk]

could the quack be a spark plug leak or an exhaust manifold leak? is it worse when cold?

[edmondclinton]

Does the sound increase as the spark is advanced or decrease as the spark is retarded? Does the sound get quieter after the engine warms up?

[Patrick L.]

I'd recommend isolating the noise a 'little more better'. A stethoscope, big screwdriver, dowel, etc can be used to try to pin point the noise.
It could be many things, as said. Excessive valve lash, broken spring, exhaust leak, timing gear, etc.

[Rowdy]

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Take the fan belt off and start it briefly and see if it goes away. That would eliminate the waterpump and generator. Rod

[DANA BIZZELL]

Tony, I had a crank shaft pulley cracked and was making a clacking sound.
Thanks
Dana

[Greg Jones]

Since we are stabbing in the dark here, how about loose engine pans? I had a horrible loud squealing that sounded like the driest of dry bearings burning itself to pieces. Turned out to be a loose bolt on an engine pan setting up a "harmonic" vibration. Of course yours is a "clack" but might be worth checking as other guys have told me they have had loose engine pans make all kinds of oddball noises.

[Archie Cheda]

My "clack" at idle turned out to be a loose valve seat insert.

[tbirdtbird]

pull one wire at a time to see if the clack goes away. IOW try to localize the noise.

Having said that, it doesn't always work.

Could be piston slap, too. Engine recently overheat??

you will end up pulling the VC and the head

[Tom Wesenberg]

You can buy 3/8" ID clear hose cheap at Menards. Use about a 3 foot piece, hold one end in your best ear, and move the other end around the engine to locate the noise.

[SeaSlugs]

does it clack upon engine deceleration? like build up rpm then let off the gas fully.

[pat in Santa Cruz]

a loose timing gear will sound like all the valves are loose when idling, but gets more quiet at higher RPM

[larrys40]

I agree with pat above that I would check the timing gear first , reverse the pin while the engine is running and put inward pressure against the gear and see if it quiets down . You migt want to remove the fan belt first for safety , up to you .
If it gets quieter you know it is the timing gear .
You can pull the side inspection cover and also see how the teeth are and if it moves fore and aft .
Larry Shepard

[juke joint johnny]

If the generater has one of the pressed steel pulleys on it, some times the rivets work loose and that can produce a claking sound .

John Cochran

[CarlG]

I had a clacking sound like that. It would stop after maybe 30 seconds or so. Found out later that it was a couple of valve inserts that had come loose, #3&4 Exhaust.

[Cool Hand Lurker]

Originally Posted by Rowdy

Take the fan belt off and start it briefly and see if it goes away. That would eliminate the waterpump and generator. Rod

Like Rowdy says, taking off the fan belt is the first thing you should do for a couple of reasons. Besides indicating whether the water pump and generator are the cause, it is easy to do. And it gives you the opportunity to check out the fan for cracks near the center. Check the generator and fan pulleys for looseness, cracks or misalignment. These things can create sound when they are rotating. Check the water pump shaft for bearing wear and fore and aft movement. Too much movement will cause the end of the shaft to bang against the inside of the head casting and cause that sound.

[Mikeinnj]

Originally Posted by g baese

tony-
1f, at idle it quacks. Not a knock but quackity quack. Sounds like its coming from #1 or 2 cylinder area... At speed it's quite, other than a quack now and then, and at idle quack quack quack, and you are just wondering about the duck in the engine.

Check to see if the exhaust manifold gasket is quacking around #1 and 2. If not, remove the valve chamber cover and look inside for evidence of a quack, and if that doesn't reveal anything, taking the head off is the best way to get the duck out.
Tic, and good luck,
gb

Not quacking - c l a c k i n g ....as in clickity clack .

[Patrick L.]

Some responses just quack me up !

[buddridge]

This thread brought this to mind....old but still funny.

Model A Engine Repair Price List

PING-PING-PING...............$35.00

PLUNK-PING-PLUNK..........$50.00

KLUNK-PING-KLUNK........$125.00

THUD-KLUNK-THUD.........$200.00

CLANK-THUD-CLANK.......$325.00