if the vehicle shifts and drives fine. the most probable cause for this is a high idle. most vehicles idle at around 650 to 700 rpms. when warmed up, check or clean the idle air control if idle is high. good-day !
Depends on where the noise is whats making the noise. Can you be more descriptive of where and what?
you have a bad alternater or belt
No, that has nothing to do with idle speed.
When you can not figure out why your car makes a strange noise, you take it to a mechanic.
Yes if it is stuck open.
I would get it checked out by a profesional because that one is a hard one to deal with if it doesnt get done right
chech catalyc converter or muffer. check also o2 sensor or egr valve.
It's usually a vacuum leak.
Adjust your idle.
Have you checked your Exhaust Muffler and pipes ? Probably the fuel pump
I could be the cooling fans running constantly. My 2001 L200 is doning the same thing, I'm still trying to find out why both Cooling fans run when the engin starts. It started a few days ago, It was so loud I thought it was a car ahead of me with it's horn stuck on.