Hey guys I have a 95 camaro 3.4 v6 engine
when I rotate it by hand it makes a click clack sound seems like it's coming from the top where the cam is.
I can't identify it maybe somebody on here knows something
I took a short video of the sound

 

The bad part of trying to diagnose based on video sound is there is no feel and since there is only one mic there is no depth or direction to the sound.

Based on how often the noise is per revolution I would guess either a issue with the timing chain or the crank gear on the chain or a spun rod bearing.

If you lay your hands on the rockers can you feel the tapping more is some rockers.

What did it sound like running? Was it rhythmic or did sound like marbles in a blender? Seems like it would really sound bad. How is the oil? Drain some through a rag and see if it leaves behind metal flakes.

 

When i had it running it sounded like pinging tapping noise coming from top end rod bearing would be more dull this doesn't sound like that.
Kind of sounds like this bad piston wrist pin except mine has a spring sound to it.

I'm going to try an stick a stethoscope needle on the edge of spark plug holes and rotate see if I can hear anything and maybe take the timing cover off and look in there i want to wait a little see if anyone had something simular to this

Here's the video of someone's bad piston wrist pin

 

The wrist pin should only make noise when it changes direction. So if you are getting the noise and you are applying the rotation back and forth Clock wise, counter clock wise it could be a wrist pin. That is a pretty loud click for a wrist pin and that would sound like the motor was coming a part if that was in a running car.

Did you ever hear the car run? Failed wrist pins sound a lot like spun rod bearings. How I used to tell was which was which was pretty simple. If it is louder under the car it is a rod bearing if its loudest under the hood it’s a wrist pin. Of course, with the way sound travels through a solid it is still a bit of a guess. If you could slide a piece of wood in the cylinder and set it on the piston you may be able to "feel" the click.

Now the bad news. If it is a wrist pin and it that loud there is a good chance it damaged the cylinder beyond the point of repair. Unlike your video, GM wrist pins in that era are pressed fit and do not have those snap rings that trap the wrist pin. If the pin gets loose the only thing holding it in place is the cylinder wall and the pin is a lot harder than the cylinder wall. Who knows what cause the damage but the most common cause is overheating enough to seize the piston in the cylinder. If that is what caused it will have more issues then just the wrist pins. This engine was only made 3 years and only for camaro’s/Firebirds so they can be hard to come by. They were hard to come by 10 years ago.

 

I took off the timing cover and saw the timing chain guide was chewed up and the chain has alot of play to where its hitting the guide and making that noise after I took the guide off and spun the engine everything is fine but I'm still looking around for the chunk off that guide cause it wasn't in the oil pan

 

 

And yes these engines are hard to find parts for I've been looking for a timing chain setup and all of them say they will fit but the designs of the sprockets aren't identical as the original one I have on and some dont even have an alignment arrow on them also ordered a couple sensors that ebay verified that they would fit yet they didn't had to return them so yeah it is a pain to find parts for this engine and I'm not trying to spend to much on this engine because I already spent a good amount and it's nothing but a old junk engine lol

 

You can still use the timing gears assuming the current chain did not jump. Put you current timing gears in alignment. Put a chalk mark on the block that lines up with the dowel pin on the cam that located the gear and a chalk mark aligned with the keyway on cranks. . Remove the old gear and install the new one. If you can get the chain installed without moving the CAM or the Crankshaft then it should be alighted.

 

I don't think it jumped timing every 720 degrees the bottom sprocket and top both line up like they should top sprocket 6 o clock bottom sprocket 12 o clock both marks facing eachother also checked cylinder #1 through spark plug hole it's all the way up

well see how it goes its my first time doing timing so I'm not in a rush checking everything cleaning all the gasket surfaces sure does look like a 28 year old engine with all these rusted coolant pipes bolts and dry Roth o'rings and stuck gaskets