Loud pop (like a fire cracker?) and white smoke under hood then car started fine with no problem and ran smoothly

SOURCE: Smoke

1. Sometimes the steam from under the hood, because it is over heat.

1. Check the water hose include the heater hose, it is a smaller hose behind the engine on the top near the back of the hood, find out which hopes is leaking.

1. If the hose is OK, check the freeze plug on the engine, because if the engine is too old, maybe the plug was rust and leaking, when it’s leaking, the engine is hot, you will see the steam under the hood.

1. When engine is hot, you have to be very carefully, do not open the water cap, if you want to open, you have to either wait a while or use a heavy towel to cover the radiator cap, then open it.

1. Maybe the radiator is leaking.

SOURCE: Engine Had serious missfire and sputtering

Good Idea Do that Fast They Gey EXPENSIVE FAST

SOURCE: white tail smoke, both temp gauges (oil/engine)

Alright there your on the money there. A4 audi's and The 2liter golfs do haed gaskets at around 145-150,000 miles. the oil's foamy kinda yellowie cream. Tip for ya When you do the head gasket cahnge the rad and water pump at the same time. Mine didthe same it's costly but worth it for piece of mind, Plus is the only time you get to the water pump apart from changing the timing belt.

SOURCE: Smoke comes from around engine

If you saw where the oil came out then that is the repair needed. It may not leak enough oil to get to the ground. Engine temp will make the oil leak smoke before it ever hits the ground. It may be valve cover gaskets because when they start to leak the oil gets all over the exhaust manifold and the exhaust manifold runs very hot. Rate if this helps

SOURCE: Why would white smoke come out from under the hood

Head gasket