White smoke blowing out of exhaust?

What is year--make--model?
Are you losing coolant? The white smoke may be coolant in the combustion cylinder, possibly caused by a head gasket problem. If head gasket problem, fix that first.

With idle issues, clean/check anything that has to do with idle air system. Any applicable trouble codes?

White smoke out of the exhaust indicates moisture (water) in the exhaust. If the car is not driven very far each day, some moisture will collect in the muffler and cause white smoke for a short while after starting. If the smoke is continual, however, you need to watch you coolant level as you may have a blown head gasket.

white smoke can be water in the exhaust if you park with the rear end facing up hill it will store water in the cat and take a few miles to clean out. 2000 rpms is a bit fast. should be around 800-900 rpms. it could be a sticking idle control. take it off and give it a good clean out.

White smoke is usually a sign for a bad head gasket. How much white smoke is coming out? Also, are you losing coolant and can't find a drip under the engine?

There may be a problem with the idle air control circuit. Make sure that the throttle body and idle air passages are clean. If not, you may have to do a throttle body cleaning on it. You can follow the directions on the can, but you will have to make sure that you give it a few shots with the throttle plate closed, so that the cleaner can get into the idle air passages. Also, make sure that there are no vacuum leaks and there is not any un-metered air that is entering into the intake. If the exhaust is blowing out and blue smoke, then the piston rings may be worn or stuck and the combustion chamber all carbon built up. If it blows out black smoke, then it's running too rich.

white smoke is a blown head gasket [white smoke burning anitfreeze]

exhaust is starting to blow what ? Yes exhaust blows out usually carbon which is CO2 out the pipes so please explain what is it blowing out when most cars do this all the time. Is the smoke that is blowing out of the pipe looks like white smoke or some other color ? Please tell us thanks.

White smoke usually indicates antifreeze. But depending whether you spilled it in the exhaust system when you changed engine it should eventually disappear. When running loud do you mean the exhaust system is not hooked up. Was the throttle stuck open or is there a vacuum line off

White smoke when runing means blown head gasket or very low compression...

The most likely cause is a blown head gasket,but it could also be a warped head,was the motor overheated prior to the problem starting? The white smoke is steam,check the underside of the oil fill cap and dipstick for a grayish brown residue,check the coolant for a low level and oil conatamination,either of these conditions verify that a head isn't fully sealed.Unless your moderately skilled mechanically this a job to be done by a shop.A good shop will perform a leakdown test to verify this.