I have a 98 olds Alero 75000 mi . when starting up a clicking noise will start after 1 or 2 minutes. It sounds like a valve sticking.It will disappear if I let the car warm up until totally warmed up. At least 15 minutes. This ticking might go away if I shut the car off and start it up all over again. Sometimes not. Sometimes in the afternoon I start it up…no noise. I have put additives in oil and gas. It has gotten slightly better but not gone away. Any ideas as to what this is? This car is running smoothly and quiet exept for the tick.
Could be sticking lifters. Try using a synthetic oil next engine oil/filter change. This oil lubricates engine parts more quickly than dino oils.