ok, this is my problem and i really would like to find my problem. I have a 1998 cavalier z24. This motor has 80k miles on the lower end, it came from a grandma motor out of a 4 door cavalier. I then put a brand new head on top of it. It just doesn't make any sense, when my car warms up and the oil pressure drops to around 40psi, which is still good oil pressure for this motor, it starts to make a chattering noise or like a ticking and when i turn the steering wheel slightly until the power steering kicks in it goes away until you let go of the wheel. I have recently heard that it can be something with the timing, so i took it to the shop i work at and had our mechainic replace the timing chain tensioner, timing chain, which were both already pretty much new from when i replaced the top end and the timing chain shoe with the new stud bolt. I don't understand, now when my oil pressure drops to around the same or just a little lower the noise is still there, however, not as bad. Any clue? I would really like to find this out because it is starting to get annoying.