Damn knock!!
I had the exact same problem with my 96 SS, but mine came at only 65k on the clock. Like you said, mine ran like dirt after it developed the knock. The knock came from no where, I parked it one night after work, came out and started it the next morning and there it was. I called my step dad who sold me the car, and is also a mechanic, and he promised me nothing was wrong with the car. So I continued to drive it. I could here the knock when starting it up, and low rpms, but when I put my foot down a little it was gone. Beware it doesn't stay that way forever. I took it to a mechanic, he told me a needed a tuneup, even though it had only been 10k since my last one. I decided to get the tuneup, and $500 later sure enough the knock is still there. Nothing was getting worse, so I continued to drive it, and everything was fine for about two months except for the embarrassing knock. I came out and started the car one day for my lunch break and the knock was ridiculous, but no extra loss in power, and no money until payday I decided to drive it until I got my check. WORST DECISION EVER. Each day the knock got worse and worse, but still no noticeable loss in power. Then while driving to work on the highway the car just jerked back and started hopping I pulled over into the shoulder, but before I came to a stop I heard a loud pop, and smoke went everywhere. When I got out of the car I noticed all of my oil from the from the car to about ten feet away. Towed it home and decided to play mechanic which is something I've never done, took off the valve covered and under the passenger side cover I noticed a rocker arm just laying in there not connected to anything, I called my step dad who looked at the car, and I had thrown a rod. I suggest you drive it as little as possible, and have it checked out by a credible mechanic, and get the problem fixed before you wind up like me. I wound up spending over $3,500 for something that probably would've been somewhat of an easy fix. I don't know much about cars I just like to drive, and if you have the same problem I did you won't be driving after long if what happened to me happens to you as well. Sorry for making this so damn long, I hope it was at least a bit helpful.
I had the exact same problem with my 96 SS, but mine came at only 65k on the clock. Like you said, mine ran like dirt after it developed the knock. The knock came from no where, I parked it one night after work, came out and started it the next morning and there it was. I called my step dad who sold me the car, and is also a mechanic, and he promised me nothing was wrong with the car. So I continued to drive it. I could here the knock when starting it up, and low rpms, but when I put my foot down a little it was gone. Beware it doesn't stay that way forever. I took it to a mechanic, he told me a needed a tuneup, even though it had only been 10k since my last one. I decided to get the tuneup, and $500 later sure enough the knock is still there. Nothing was getting worse, so I continued to drive it, and everything was fine for about two months except for the embarrassing knock. I came out and started the car one day for my lunch break and the knock was ridiculous, but no extra loss in power, and no money until payday I decided to drive it until I got my check. WORST DECISION EVER. Each day the knock got worse and worse, but still no noticeable loss in power. Then while driving to work on the highway the car just jerked back and started hopping I pulled over into the shoulder, but before I came to a stop I heard a loud pop, and smoke went everywhere. When I got out of the car I noticed all of my oil from the from the car to about ten feet away. Towed it home and decided to play mechanic which is something I've never done, took off the valve covered and under the passenger side cover I noticed a rocker arm just laying in there not connected to anything, I called my step dad who looked at the car, and I had thrown a rod. I suggest you drive it as little as possible, and have it checked out by a credible mechanic, and get the problem fixed before you wind up like me. I wound up spending over $3,500 for something that probably would've been somewhat of an easy fix. I don't know much about cars I just like to drive, and if you have the same problem I did you won't be driving after long if what happened to me happens to you as well. Sorry for making this so damn long, I hope it was at least a bit helpful.