speedpenguin

Thank you, I more meant safe for the engine. Like if the sound could be a piston hitting a valve, and that the car shouldn't be driven. What other cases that could be making a rattling noise could be severely detrimental to the engine. Thank you.

It is just warming up, so it is higher, but even after warming up, the Sound is present. Is it safe to drive? At the least to a mechanic friend's place about 10 miles away? What are possible causes that would make it unsafe (to the engine) to drive?

AH yes, I forgot to mention that the noise increases speed when I rev the engine. Someone asked if the rattle seemed to be at engine speed or half engin speed to help narrow down the source, that is why I am going to get the timing light. The noise increase in volume as I rev the engine, but seemingly because it's happenging faster. Apparent location of the sound doesn't change. Although the rattling sound sounds like a physical object contacting another, I won't rule out the possibilty of the manifolds leaking air/exhaust.

I have 2 videos of the noise, you can see the shorter one here: I think you can see the other by looking at my videos (I only have Internet on my phone at the moment) I bought this car 2 weeks ago, immediatly did an oil & filter change, and I replaced the plugs and wires with NGK ones. I didn't notice the engine rattle until after the oil change, but I then noticed it was present in a video I took the night I bought the car. I adjusted the valve lash 3 days ago while the engine was cold, most were close to the specs, but only 3 valves didn't need adjustment. I also did a cold engine compression test and all cylinders were between 145 and 152 psi. The front three spark plugs look pretty different from the last 3, I'm guessing the carbs are out of sync, they are the stock flat tops. The 4th plug is fouled wet and black, and I'm sure it's not firing because the engine doesn't bog when I remove the plug wire, but it is getting spark. The rattle seems to be coming either from inside the engine, or around where the intake and exhaust manifolds are. It doesn't quite sound like the noise is coming from the valve cover, but I wouldn't rule it out. I haven't gotten a stethoscope or. Timing light yet, but I plan to tomorrow. I have Read several posts pointing to a worn timing chain tensioner, but wouldn't that sound come fronthr front of the engine rather than all the way down it? I can take more videos or pictures, just let me know. Thank you, Matt