Mercedes-Benz SLK-Class 2008 Owners Manual - Manual (Page 291)

290
Operation
Driving instructions
! Excessive coolant temperature triggers a
warning message in the multifunction display
(
୴ page 374).
The engine should not be operated with a
coolant temperature above 248°F (120°C).
Doing so may cause serious engine damage
which is not covered by the Mercedes-Benz
Limited Warranty.
i During severe operating conditions, e.g.
stop-and-go city traffic, the coolant temperature
may rise close to 248°F (120°C).