The valve seals may be shot or the oil return holes in the ends of the heads may be plugged allowing oil to build up and run down the valve guides.
Because it is burning fuel in its cylinders.
Yes.
A TDI or turbo direct injection engine supplies diesel to each of the cylinders under pressure. On the other hand, the a quadrajet engine only uses one pipe which contains the fuel for all cylinders. When the pressure of the pipe increases, fuel is automatically injected to the cylinders.
The heat - is generated by the fuel/air mixture burning in the cylinders.
An external combustion engine is one in which the oxidation of the fuel occurs outside the engine, which provides heat to the motive portion of the engine. External combustion is characterized by burning the fuel outside of the moving parts, as opposed to burning fuel inside the cylinders of an internal combustion engine. The Steam engine, using steam pressure, is an example of external combustion, as in the "Stanley Steamer," an early motorcar; and in steamships The combustion is in the boiler, not in the cylinders that convert steam pressure and volume to mechanical work. Internal combustion engines include diesel and gasoline vehicles (explosive fuel mixes), gas turbines, and most jet aircraft engines.
High pressure is created by an exploding gasoline-air mixture. This pressure pushes the cylinders of the engine down, doing work that moves the car.
Don't touch the hot parts with your legs
Boosts the performance and makes the car faster. Most diesel cars have a turbo. It increases the amount of air and air pressure available to the engine therefore improving efficiency in burning the fuel and scavenging the cylinders.
Burning excessive oil in the cylinders is the culprit. Scored cylinders and broken rings will usually contribute to blue smoke. Once it turns black, the engine is toast!
the unburned charge in the cylinders explodes instead of burning normally.
An external combustion engine is where something is burning outside of the actual engine and the energy is transmitted to the engine via something. (e.g. boiler creates steam that goes to the engine a.k.a. steam engine) In an internal combustion engine, the burning happens in the actual cylinders of the engine. (e.g. car engine)
if they fixed the seal, it could be the residue of the leak just burning off the block, cylinders, exaust manifold and where ever else it dripped on. get the engine cleaned, or wait a few weeks to let it burn completely off.