What causes white smoke from tailpipes?

SOURCE: 1999 Dodge Ram 1500 runs ok til warm, then..

Have your battery tested. When the battery has a problem the dodges will act this way.

SOURCE: my truck blows white smoke

Hello!
There are two differnt reasons for black and white smoke coming from the tail pipe.
Black smoke means fuel runs rich (car getting to much gas). Check fuel pressure/air filter.
In some cases the white smoke means car is burning oil or transmittion fluid. Have tem checked/replaced.
If you can feel a smelly smoke it can be catalytic converter.
In a worsest scenario if car blowing white smoke it can be engine coolant is getting into an engine cylinder from a bad head gasket ,or a warped/cracked head. So you need to keep your eye on coolant level and check your engine for overheat. Also might be good to check your oil for traces of coolant (on a dipstick it would be a milky substance mixture of oil and coolant).
Good Luck

SOURCE: 325i BMW emitting white smoke

You are smelling burning antifreeze. likely a head gasket but only testing will determine that for sure...Do not drive it. get it to a shop or more damage is likely.

SOURCE: white smoke on startup, missing, shaking, no codes

this sounds like you have an injector leaking and is dripping raw fuel into the combustion chamber this would explain the miss and the white smoke.

SOURCE: 2002 civic ex overheating

with your description it sounds like your fans are not coming on, also sounds like the problem was never solved, sounds like you threw a lot of money at your problem also... check to see if the fans are coming on at the right times, seems like a n air movement over the radiator since you say it only gets hot in stop and go traffic... well when your driving at a constant highway speed guess what you have air movement through the radiator... check also a clogged ac condensor with bugs, pressure wash it out so the air can pass through it easily... please rate my help thanks