Diesel engines from:  https://en.wikipedia.org/wiki/List_of_Mercedes-Benz_engines#Diesel_engines

One-cylinder

    MB851, 1.5 L
    MB861, 1.5 L

Two-cylinder

    MB852, 2.9 L
    MB862, 2.9 L
    OM632, 0.8 L
    M202B, 6.5 L (1947–???)

Straight-three

    MB853, 4.3 L
    M203B, 9.7 L (1947–???)
    MB863, 4.3 L (1954–???)
    OM660, 0.8 L (1998–2015)
    OM639, 1.5 L (2004–2009)

Inline-four

    OM138, 2.5 L (1935–1940)
    OM636, 1.7 – 1.8 L (1949–1990)
    OM621, 1.9 – 2.0 L (1959–1967)
    OM615, 2.0 – 2.2 L (1968–1985)
    OM616, 2.4 L (1973–1985)
    OM601, 2.0 – 2.3 L (1983–2001)
    OM604, 2.0 – 2.2 L (1993–1998)
    OM668, 1.7 L (1997–2005)
    OM611, 2.1 – 2.2 L (1998–2011)
    OM646, 2.1 L (2002–2010)
    OM640, 2.0 L (2004–2012)
    OM651, 1.8 – 2.1 L (2008–present)
    OM654, 2.0 L (2016–present)
    OM699, 2.3 L (2017–present)
    OM608, 1.5 L (2018–present)

Inline-five

    OM617, 3.0 L (1974–1991)
    OM602, 2.5 – 2.9 L (1985–2002)
    OM605, 2.5 L (1993–2001)
    OM612, 2.7 L (1999–2006)
    OM647, 2.7 L (2004–2006)

Straight-six

    OM603, 3.0 – 3.5 L (1986–1997)
    OM606, 3.0 L (1993–2001)
    OM613, 3.2 L (1999–2003)
    OM648, 3.2 L (2002–2006)
    OM656, 2.9 L (2017–present)

Busses and trucks:

    OM5, 8.6 L (1928–1932)
    OM49
    OM54, 12.5 L (1934–1939)
    OM57, 11.3 – 12.5 L (1938–1940)
    OM65
    OM67, 7.2 – 7.4 L (1935–1954)
    OM77
    OM79, 10.3 L (1932–1936)
    OM302, 4.6 L (1941) (prototype)
    OM312, 4.6 L (1949)
    OM314, 3.8 L
    OM315, 8.2 L
    OM321, 5.1 – 5.7 L
    OM326, 10.8 L
    OM346, 10.8 L
    OM355, 11.6 L
    OM360, 8.7 L
    OM352, 5.7 L (1963–present)
    OM364, 4.0 L
    OM366, 6.0 L
    OM407
    OM427
    OM447
    OM457, 12.0 L (2003–present)
    OM460
    OM470, 10.7 L
    OM471, 12.8 L
    OM472, 14.8 L
    OM473, 15.6 L (2012–present)[2]
    OM906, 6.4 L
    OM926, 7.2 L
    OM936, 7.6 L (2012–present)

V6

    OM642, 3.0 L (2005–present)

Busses and trucks:

    OM401, 9.6 L
    OM421, 11.0 L (1982–???)[3]
    OM441
    OM501, 12.0 L

V8

    OM628, 4.0 L (1999–2005)
    OM629, 4.0 L (2005–2010)

Busses and trucks:

    OM402
    OM422
    OM442
    OM502

V10

    OM403
    OM423
    OM443

V12

    OM404, 20.9 L
    OM424
    OM444, 22.6 L
    MB500, 66.4 L (used in e-boats)
    MB507, 42.4 – 44.5 L
    MB512
    MB517, 42.4 L (used in Panzer VIII Maus V2)
    MB820
    MB835

V16

    MB502
    MB512
    MB839, 104.3 L

V20

    MB518, 134.4 L (1951–1973)