[R32REG]

Based on what I've read in this forum I always thought running a diesel empty was a costly mistake.

I can't find it on automotive sites but I see John Deere's Yanmar Diesels explicitly state you can run them dry and the system will re-prime itself.

Is this also true of modern automotive diesels? Was this only a problem for older diesels?

 

[Pilot]

i remember once i had a YOM 2000 Jetta , that ran on both veg oil and diesel
for some reason , only the veggie oil tank worked i believe it was a switch problem that couldn't get the main tank going , the veggie oil tank that was installed in the trunk inside the spare tire compartment didn't have a gage , so basically i filled it every 200 miles ,
that time i lost track of mileage and ran it completely dry , luckily , the engine shut down about 20 feet away from a gas station that had diesel )
i got the tank filled up , but the engine didn't start for about 30 cranks .
i knew there was air inside the fuel lines , i guess it took 30 tries to start the engine to get it out of the system .

 

[Yeti]

I've never run completely empty, but it did not have much in the tank when I filled it up. I have no side effects from that miscalculation error. I was driving from UT to PA and did not plan my fuel stop very well at one point. I was stressing if I was going to make it to the next stop.

 

[Marbles]

Never run the CR diesels dry, diesel is the lubricant and cooling for the lift pumps and hpfp. Also in order to reprime after requires Ross-tech, trip to dealer, or jumping wires on the lift pump. Other diesels namely Duramaxs have a mechanical primer(hand pump and vent) on the filter housing and the hpfp is more tolerable to run dry. As a side fact a Duramax can run when supplied at half pressure of the hpfp, not sure if any vw would be able to.

 

[roalco]

The difficulty level of re-priming the fuel system notwithstanding, never run ANY diesel dry. As said before, the fuel pumps, whether Bosch type running at between 3000-5000 psi, or common rail, running at 25,000psi +, are all positive displacement pumps, in which the reciprocating pistons are of the perfect sliding fit ( no radial clearance, whatsoever) type, and are entirely dependant on the fuel being pumped for lubrication and cooling. If your engine is running when you runout of fuel, you are going to be continuing to run the pump thousands of piston strokes, while your vehicle comes to rest. It may continue to run when refuelled and restarted, and you may think that you "got away with it" but guaranteed the HP fuel pump will have suffered accelerated wear, and will be delivering reduced delivery pressures (reduced power and efficiency) equivalent to many thousands of kilometres of driving.