Q: My truck wont start. I was driving it earlier and a big cloud of white smoke came out of the exhaust and it completely shut off

Hello and thank you for contacting YourMechanic. White cloud of smoke from the exhaust means that the engine coolant has gotten into the combustion chambers of the engine and is burning the coolant. This could be caused by a blown head gasket, warped or cracked head, a corrosion burn in the timing cover behind the water pump, or a cracked block. To check for a head gasket, get a block tester tool. Put the blue fluid into the tester and install the plunger. With the engine running at cold temperatures, remove the radiator cap. When you see steam come from the radiator, place the tester over the steam and squeeze the plunger. This will suck the steam into the tester. If there is any carbon deposits (gasoline) in your coolant, then the blue color will turn yellow or orange. If you have a yellow or orange color, then the head gasket is blown and needs replaced. If you need further assistance troubleshooting your vehicle, then seek out a technician, such as one from YourMechanic, that can assist you with your vehicle.