Hi, i have a question and need some help. I have an Automatic D wit 50,000+ miles and dont reallly drive it, Whenever I start it about once a week or whenever it always has to run for like 5 minutes. The RPM needle goes from like 10 to 25 and then slowly after sittin for like 2 minutes idles back around 10. My mechanic said this is normal buit he really doesnt know much about d's and I dont think this is normal. He told me this was only because it is cold out but now it is summer and the same problem still happens. Can anyone please give me some help? Thanks so much BRIAN