As I stated earlier, I was unsure if the vacuum pump discharge into the crankcase was a "design consideration" when MB designed the OM 617.xxx engines......was just putting forth a possible reason for doing this....

Then I got into answering questions.....

Usually, if there is a crankcase explosion.....something was bad wrong beforehand.....and it is a phenomena of "large" Diesel engines......I would imagine it can happen in any Diesel Engine, however would most probably be unlikely in an automotive application.....please bear in mind that the industrial engines, no matter the application, tend to run continuously for long periods of time...days, weeks, months......and generally have thousands of more hours on them than the average automobile......even long haul trucks.....!!!

SB

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Diesels:
'85 300D, "Max, Blue Benz", 155K, 27.0 MPG
'84 190D 2.2, "Eva, Brown Benz", 142K, 40.2 MPG
'77 240D (parts car)
'67 Eicher ES 202 Tractor "Otto" (2cyl, Air Cooled, 30HP)
Gassers:
'94 Ford F-150, "Henry", 170K (300 Six) 17.5 MPG
'85 190E 2.3, 148K....Parts Car
'58 Dodge W300M Powerwagon (Flat Fenders) Less than 10 MPG