Audio Diagnostics

OK Gang. Changed out the Intake and exhaust manifolds as well as checked valve springs and set all the valve spring clearances, but..... still have this clack clack clack noise coming from the engine. Vacuum testing shows gauge bouncing between 20-22 rapidly. A relatively new occurrence. Any ideas?

THIS is how it USED to sound:
https://vimeo.com/239275820


THIS is how it sounds now
https://vimeo.com/273119710



Edited by cal.bar - 02 June 2018 at 7:55pm

otto wrote: Do you have a mechanic’s stethoscope? It might help you locate where the noise is coming from.

I don't but the noise seems to be coming from right in the middle of the engine block (or so it seems)

Thanks Capt. Great ideas! Sadly (or not) I removed the fan belt and ran it and there was no change in the sound of the engine. All motor mounts look fine. The eng. is not shaking or rattling, but it just makes that clak clak clak noise. I doubt that I suddenly lost compression in one or more cylinders so as to suspect that. Still wondering if the new exhaust manifold and/or intake manifold could be the issue since they are the only thing to change before the new clacking sound.


Edited by cal.bar - 03 June 2018 at 3:43am

athawk11 wrote: You won't believe what my issue ended up being.

And the diagnosis was.......(suspense continues)

Sorry. Sometimes I like to build up the suspense.  

So... setting aside the screw for a moment, could it be a piece of carbon (from the removed manifolds for example)? Would running some seafoam or other additive make any sense before pulling the head gasket?

Also, saw a guy on YouTube use a micro camera to go down the park plug hole to view the top of each piston. I suppose I would be able to do that first w/o having to pull the head! That would (in theory) show me the top of the piston where Tim's screw came to rest. Although not sure what to do if the problem were below the piston.

Edited by cal.bar - 03 June 2018 at 6:07pm

athawk11 wrote: cal.bar...The simple part is to look down the throat of the Carter and make sure both screws are still holding the throttle plate to the throttle shaft. A more involved diagnostic is pulling the head to see if a chunk of carbon or a chunk of piston has broken free.  But I wouldn't do this until you determine if the knock sounds like it's at the top of the engine.

If you mean the choke plate right up near the top of the carb, yes, I have both of those in place. I only removed the two big bolts at the bottom of the carb to take the entire unit off, I didn't fiddle with anything inside.

But, perhaps a piece of a ring or carbon have gotten in there?

Don't laugh-is your dipstick bent? Unscrew it, turn it 180 degrees and screw it back in.

I will use the new camera to take a peek at the top of the Pistons. But I can't help but think it has something to do with  a manifold leak. I replaced the manifold gasket when I replace the exhaust manifold, however I am wondering if any of you have had experience with a manifold ceiling gasket maker kind of like Permatex that is impervious to the Heat for a little more reassurance in terms of seal

Edited by cal.bar - 04 June 2018 at 2:35am