Fast Idle on 1988 Lxi coupe

It's not uncommon to hear some valve noise, especially with an engine of that mileage. Did you replace the oil pump when you did the engine rebuild? Check your oil pressure output to make sure you got a good oil pump. How is the timing on the engine? Everything OK there? Also, check your valve lash adjustment, it's possible one is a little loose. If this is a carbureted engine you may be able to adjust the idle but if it's fuel injected it's likely completely computer-controlled. Check for vacuum leaks as well which could cause idle problems. Hard to say what the valve noise sounds like without hearing it, but I will say that both of my wife's Toyota Camry's used to make a chattering sound all the time with no ill effects. Kind of like a sewing machine sound from the valve train.

The head was rebuild, and the shop did the install on it, they adjusted the valves, so I'm not sure if one is out, but it could be, but it only makes that sound on "cold" startup, it could be the pum, we didn't replace it, so darn, maybe I should have, the oil is the dickens to get off, and I guess I will went or if I have to get inside it again. Unless if you have any easy ideas. The sound disappears in a few seconds, but I worry about the valves, could I try stp for help, or should I change the oil next time to 5W-30 instead of the 10W-30? Anyway thanks for the help, I'm replacing the Alt. I was told the regulator went bad, brushes are okay, My father in law, picked up a used one (89 DX) but the plug is diff. then the one on mine, I was wondering if the reg. could be pullled out and put in my Atl.? he was told because it has a dash gauge, not a light, they won't interchange. thanks guys