I have this El Camino and it starts and runs fine, but when started the engine idle is very high. When I kick it down to low idle the engine knocks, but it doesn't knock at all at a high idle. I was told it was a rod, but it should knock at all times, not just at a high idle. I've also heard it could be a cracked flywheel? I'm not sure and I'd rather figure it out and save myself from buying a new engine altogether.