Q: Car is idling at high rpm's and when the days are hot the car cranks but doesn't turn on and also exhaust is smoking when i rev it

There are a few possible issues for each of the issues you have described. It’s possible that they are individual issues, or that they may be related. As far as the high idle, this could come from a vacuum leak, malfunctioning idle control, or a faulty sensor. The smoke from the tailpipe when revved could have a couple of possibilities, also. There could be faulty valve seals, worn piston rings, or any number of other issues. Knowing what color of smoke coming from the tailpipe will help narrow down the suspects. The one thing that comes to my mind, with the list you provided, would be to check the pcv valve and the plumbing for it. A clogged pcv valve can cause a lot of the issues you have mentioned. If you feel you could use a hand in diagnosing/repairing an issue, contact a certified mechanic, like the mobile mechanics available at YourMechanic.com.

Hello - your symptoms suggest worn piston rings or valve stem seals (smoking), and a possible air leak in the intake, or idle air control valve sticking open (high idle). Both are signs of a higher-mileage engine with significant wear. I recommend an engine inspection performed by a mobile, professional mechanic, such as one from YourMechanic, who will come to your location, diagnose this problem, and give you an accurate assessment of damage and cost estimate for repairs.