sounds like a beetle

Here it is: 97 sl1, 160,000 miles. This car has been very well maintained since i got it at 10K. lately there has been a few things go out, nothing drastic, just wear and tear stuff. My dilema is that no matter how much unleaded i put in it, it sounds like a damn diesel. and i mean diesel

sounds like lifter tick then. could possibly be the timing chain, but im thinking more towards lifter tick.