On my 89 Firebird 350, I developed a knock. I dont have a stethescope so I just used a long screwdriver. I was changing oil anyway so I decided to narrow it down. Seems to be coming from the number 1 cylinder area. Almost as if it in the top center of the engine near the thermostat if you know what I mean. As I finished the oil change, I started the car again and put the screwdriver to the oil pan and heard nothing unusual. The only sound I could hear was that as if you hear fuel injectors ticking normally. So that is a good sign I guess. Oil pressure is at 35 or so when idling and the knocking goes along with the engine RPMs. I think it may be like a wrist pin or something instead of a spun rod bearing. May be something that mimics a rod knock such as a flywheel or flexplate. The engine has less then 20k miles on it. I know I have about 7 months of warranty left, but it can be a hassle getting warranty work done as they want receipts and records of everything. The TPS went out and my buddy sprayed starting fluid in it to get it going until the fluid burned out of course. At that time, he didnt know the TPS was bad. The TPS voltage was over 4 volts at rest so the engine would not pulse the injectors. Car starts and idles perfect, just the annoying knock sound. Any thoughts?