Don't start tearing anything apart on the presumption that something is worn out just yet. What your engine is doing right now is a very common condition in out of tune MFI systems. I'm willing to bet it can be tuned out by someone familiar with MFI. Too bad there just aren't that many shops with old hands that know this system anymore - you may be on your own. Don't worry, though, it's not that hard.

Start by going to the tech section of this very site and downloading the "CMA" or "Check, Measure, Adjust" manual from Bosch. In it you will find very detailed instructions for tuning the MFI system. Start with that. Be patient, and follow it to the letter. Do not skip a step, no matter how trivial or unrelated it may seem. Yes, it needs to have the valves freshly adjusted before you begin on the MFI itself. And fresh plugs of the proper heat range and gapped correctly. And a fresh fuel filter, and on and on. Everything else has to be right before touching anything on the MFI.

Many of these systems haved been "tuned" by folks without proper knowledge of them. As a result, many of them are out of tune. There are several faults that will lead to popping through the stacks at idle. The only way to find and correct them is to meticuously follow CMA. If you are unable to, find a mechanic in your area that can. Just ask here - it's likely someone will know of one in your area. The guy telling you that it might have a "bent camshaft" isn't going to be one of them...

+1 what Jeff said! I have the same setup and the same noises. If you take the air filter off and expose the intack stacks, you can see/hear which intakes are "popping". CMA!

Let me also add... The noises you hear in your video are certainly popping intake stacks. That's not to say that the tensioners aren't making noises. I simply can't tell. The timing chain can bang around at certain RPM's or upon deceleration . They certainly do sound like someone shaking a can of nails. That is a more serious condition that could possibly damage your engine if the chain gets enough slack to jump off the gears. It's one of the first things I fixed on my car.

Good luck!

A bent camshaft would not last long and would eat its bearings and spit them out as metal in the crankcase oil. Your intake pops are related to MFI tune and camshaft profile.

It is likely that your throttle bodies are worn. In this case, when you "Check", you may find them worn. When you "Measure" the airflow it will be off. If they are worn, you cannot "Adjust" the throttle bodies to the correct airflow (low enough) for idle and will have to compromise by enrichening the idle mixture. With throttles open, there is not so much difference. :)

Exactly.

Yup - the unfortunate reality of our old cars. Some conditions of maladjustment will actually accelerate this kind of wear. The only way to tell where it's at in this regard is to run through CMA. That will tell you a lot about its current condition, depending upon how it responds.

And yes, MFI is always best at WOT. :D