Is that the valve knocking?

[Mopewbie]

The noise is getting louder, is that a valve issue?

Here's a slow motion video where one can see/hear it exactly when the #1 intake goes down. What do I need to do here?
Thanks.

 

[Xcudame]

I'd pull the intake and check out the camshaft lobe and lifter. Should be the third line from the front (first two lines are exhaust)

 

[HPP]

Wow, sounds like a knock and seems timed with the valve motion, but I've never heard a valve sound like that.

 

[Xcudame]

I wouldn't rule out #1 connecting rod bearing either! But start with the camshaft lobe and lifter first.

 

[Mopewbie]

Thanks all. I'll need to replace timing chain anyway, will go with the whole lot of cam/lifters/rods.
Might just do the rings as well.

 

[HPP]

Let us know what you find inside there.

 

[Mopewbie]

Right, nothing new so far. Since I was going to open it, I decided to flush the water system first because - why not?

Guess what? While the engine was running to temperature to activate the flushing, the knocking stopped!
I turned the car off, had the carb loosen already and then the coin dropped... turned the car on again, all good... so maybe it was just a lifter being funny?

I ran some tests rotating the engine and the timing chain seems fine as well so, apart from the old noise that I have no idea where's coming from, all is good.