Mercedes-Benz E-Class 2009 Owner's Manual page 245

Troubleshooting
242
Problem
Vehicles with a petrol
engine:
The engine is not run-
ning smoothly and is
misfiring.
The coolant tempera-
ture gauge shows a
value above 120 †.
The coolant warning
lamp may also light up
and a warning tone may
sound ( page 107).
Y
Possible causes/consequences and M M Solutions
There is a malfunction in the engine electronics or a mechanical
component of the engine control unit.
Only depress the accelerator pedal slightly.
X
Have the cause rectified immediately at a qualified specialist
X
workshop.
Otherwise, non-combusted fuel may get into the catalytic con-
verter and damage it.
The coolant level is too low. The coolant is too hot and the engine
is no longer being cooled sufficiently.
Stop as soon as possible and allow the engine and the coolant
X
to cool down.
Check the coolant level (
X
notes as you do so and top up the coolant if necessary.
If the coolant level is correct, the radiator fan may be faulty. The
coolant is too hot and the engine is no longer being cooled suffi-
ciently.
If the coolant temperature is less than 120 †, you can continue
X
driving to the nearest qualified specialist workshop.
Avoid heavy loads on the engine as you do so, e.g. driving on
X
mountain roads and stop/start driving.
page 183). Observe the warning
Y