CatShot41

Helloooo Scotty; I have a 2001 Toyota Camry LE 2.2L 4cyl engine and automatic trans with 230K miles. First cold start of the day the idle seems to high imo, on a cold day when first starting, the rpm with lighting speed just touches 2000rpm before settling at 1800 and hangs there until the engine starts building heat, as heat builds the rpm decreases in a synchronized fashion, not until the engine reaches normal idle temp (gauge in the middle) does it idle correctly at 700rpm also after driving for several miles or at normal operating temp and stopping for 5mins restart idle is between 800 and a 1000rpm, stop for 15mins it idles between 1000 and 1200rpm or higher, summer or winter (California)is the same except for a slight rpm difference. One of my concern is oil starvation on cold mornings I can hear the engine rattle for a second while the engine is humming at 2 grand before the oil catches up, it's been that way since I purchased the car with 172k miles, can I fix it. I've done searches here a there but nothing addresses high idle I also had the opportunity to check a same year same motor Toyota solara and at cold start idles at 1200rpm constantly and starts descending about 30sec to 60sec after. I've replaced the radiator, thermostat and temp sensor for the computer using new Toyota parts any ideas.