Why cant’ you let a diesel engine run out of gas?

I’ve heard something about having to “flush the engine” if it runs out. Why is it such a problem for a diesel engine but not a gasoline engine?

Tags: can't, Diesel, Engine

7 Responses to “Why cant’ you let a diesel engine run out of gas?”

1. Marcel says:

   October 21, 2011 at 5:56 pm

   i heard somethings gonna grind out and its gonna make a hole on your gas tank
2. smokey says:

   October 21, 2011 at 6:48 pm

   diesel engines are fuel injected. if they run out of fuel there will be air in the injector lines going to each cylinder , then all the air has to be evacuated from each line.
3. BobTheBlazer says:

   October 21, 2011 at 6:54 pm

   Because air gets into the lines, and you have to “prime” it to get the air out.
4. Roy says:

   October 21, 2011 at 7:11 pm

   Smokey is right, it can be a real pain bleeding the air out. Not only that, the fuel actually acts as a lubricant for the injector pump. Running an injector pump dry will ruin it.
5. redmisten says:

   October 21, 2011 at 7:31 pm

   a fuel injected gas engine has a fuel pressure regulator so it keeps fuel at the engine and bleeds excess fuel pressure or air back to the tank on a diesel after it goes to the injection pump there is no return any air in the lines has to be bled out like you would do on a brake system air compresses so it won,t push it through the injectors like a liquid there are a few diesels like the old detroits that would you didn,t have to bleed the high pressure pump was on each injector and was operated by the cam they had a pressure and return line on each injector
6. vinylhamster says:

   October 21, 2011 at 8:30 pm

   You can. It normally won’t do any harm. However, depending on the car you may need to prime the injector pump, which can be a tedious process.
7. Albert F says:

   October 21, 2011 at 8:42 pm

   If you let it run without fuel for too long; in addition to letting air in the system since the fuel acts as a coolant and lubricant to the injectors and injector pump; you might also damage these components too.

   Diesel engines don’t run out of gas. LOL