My 05 sonata wouldn't accelerate when i hit the gas. So I pulled over. Once I did that it started to smoke under the hood. The smoke seemed to be coming by the coolant area. I don't recall seeing the temperature going up. It was dark out so I couldn't tell if the smoke was black/white....Just smelled like smoke. Is this a radiator problem? Not enough coolant? Engine blown?

hood latch malfunction, may have to hit it a few times might work or may need to get under front of car locate hood cable and pull it down should open

CHECK ELECTRONIC COILS AT PLUGS!

check fuel pressure
change the fuel filter, it could be clogged up

head gasket has blown ,

You can tell by looking at dip stick if the oil has a creamy white substance there is antifreeze getting in oil (blown head gasket) or if ther is excessive white smoke coming from exhaust pipe upon acceleration. steam from under hood may be a coolant leak from a rubber hose or it may be leaking from the cylinder head onto the exhaust manifold also the car will be using up antifreeze.

It's still under warranty... take it in for diagnosis

It's the automatic choke!

The choke is "closed" or barely open... When cold, the engine needs a RICH mixture (more gasoline, less air). When the engine warms up, it requires a LEAN mixture (less gas, more air).

It is probably creating BLACK tailpipe smoke ... that means unburnt gasoline. (Blue smoke is OIL, white smoke is WATER).

Put the parking / emergency brake ON.
1. Remove air cleaner assembly from intake, use a carb cleaner spray or throttle body spray cleaner and spray just a little. (AutoZone $5)
2. Find the accelerator arm under the hood.
3. start car, rev the engine to make sure how to operate the accelerator from under the hood.
4. Carefully spray into carb / throttle body and work the accelerator ... don't let the engine die...
5. Watch out for "backfire"... it may create a small flame out of the carb. It will extinguish itself in one second.

6. You may need to do this two, three times.
7. Add a "complete fuel system cleaner" to your next tank of gas ($8).

That's it! ... pretty cheap, too.

Hope this helps!

faulty idle air control valve or throttle position sensor.

it seems that the engine blew. the rings, rod bearings, main bearing etc. Sorry but it sounds like that. Especially the smoking at the exhaust. take it back to the one who sold it to you.If possible.

I had same problem with my 2002 Sonata. Turned out to be Ignition switch relay under the hood. $22 part from dealer. Check ignition fuses under hood also.