On almost all MB engines gas & diesel there is a plug to remove & install a block heater. On the US cars starting in 1984 the OM 601/602/603/606 engines had a block heater installed & there was a coupon good for 1 year, to install cord & in some cases insulation for cord.

__________________
MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
Retired Moderator