Page 246 of 309

Problem
Possible causes/consequences and
X
X Solutions Vehicles with a petrol
engine:
The engine is not run-
ning smoothly and is
misfiring. There is a malfunction in the engine electronics or a mechanical
component of the engine control unit.
X
Only depress the accelerator pedal slightly.
X Have the cause rectified immediately at a qualified specialist
workshop.
Otherwise, non-combusted fuel may get into the catalytic con-
verter and damage it. The coolant tempera-
ture gauge shows a
value above 120 †.
You also hear a warning
tone. The coolant level is too low. The coolant is too hot and the engine
is no longer being cooled sufficiently.
X
Stop as soon as possible and allow the engine and the coolant
to cool down.
X Check the coolant level (Y page 177). Observe the warning
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.
X
If the coolant temperature is less than 120 †, you can continue
driving to the nearest qualified specialist workshop.
X Avoid heavy loads on the engine as you do so, e.g. driving on
mountain roads and stop/start driving. The engine does not
switch off. The ignition lock is faulty.
X
Open the fuse box in the engine compartment (Y page 281).
X Remove fuse 120 using the fuse extractor.
The engine stops.
If you wish to start the engine again:
X Replace the fuse. Troubleshooting
243Practical advice
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Page 290 of 309

Engine number
The engine number is stamped on the crank-
case. More information can be obtained from
any Mercedes-Benz Service Centre. Service products and capacities
Service products include the following:
R fuels (e.g. petrol, diesel)
R exhaust gas aftertreatment additive
(AdBlue ®
)
R lubricants (e.g. engine oil, transmission oil)
R coolant
R brake fluid
R windscreen washer concentrate
Mercedes-Benz recommends that you only
use products which have been tested and
specially approved by Mercedes-Benz for
your vehicle and which are listed in this
Mercedes-Benz Owner's Manual in the rele-
vant chapter since:
R parts and service products are matched.
R damage caused by the use of non-approved
service products is not covered by the
implied warranty.
You can recognise service products approved
by Mercedes-Benz by the following inscrip-
tion on the containers:
R MB-Freigabe (e.g. MB-Freigabe 229.51)
R MB Approval (e.g. MB Approval 229.51)
Other designations or recommendations that
relate to a level of quality or a specification in
accordance with an MB Sheet number (such
as MB 229.5) have not necessarily been
approved by Mercedes-Benz.
You can obtain further information from any
Mercedes-Benz Service Centre. G
Risk of injury
When handling, storing and disposing of any
service products, please observe the relevant regulations, as you could otherwise endanger
yourself and others.
Keep service products away from children.
To protect your health, do not allow service
products to come into contact with your eyes
or open wounds. See a doctor immediately if
any service product is swallowed.
H
Environmental note
Dispose of service products in an environ-
mentally-responsible manner. Fuel
G
Risk of explosion
Fuel is highly flammable. Fire, naked flames
and smoking are therefore prohibited when
handling fuels.
Before refuelling, turn off the engine and the
auxiliary heating *. G
Risk of injury
Do not allow fuel to come into contact with
skin or clothing.
Allowing fuels to come into direct contact with
your skin or inhaling fuel vapours is damaging
to your health.
Tank capacity Total capacity 100 l
Of which reserve
fuel Approximately 13 l
!
Do not use petrol to refuel vehicles with a
diesel engine. Do not use diesel to refuel
vehicles with a petrol engine. Never mix
diesel with petrol. Even small amounts of
the wrong fuel result in damage to the
injection system. Damage resulting from
adding the wrong fuel is not covered by the
implied warranty.
Further information on refuelling and on
fuels (Y page 172) Service products and capacities
287Technical data
* optional
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Page 294 of 309

Coolant
The coolant is a mixture of water and anti-
freeze/corrosion inhibitor. It performs the
following tasks:
R anti-corrosion protection
R antifreeze protection
R raising the boiling point
i When the vehicle is first delivered, it is
topped up with a coolant that will ensure
adequate antifreeze and corrosion protec-
tion.
! Only top up with coolant that has been
premixed with the desired antifreeze pro-
tection. You could otherwise damage the
engine.
Further information on coolants and on fill-
ing can be found in the Mercedes-Benz
Specifications for Service Products, Sheet
310.1, or at any Mercedes-Benz Service
Centre.
! Always use a suitable coolant mixture,
even in countries where high temperatures
prevail.
Otherwise, the cooling system will not be
sufficiently protected from corrosion, and
the boiling point will be too low.
If antifreeze/corrosion inhibitor is present in
the correct concentration, the boiling point of
the coolant will be around 130 †.
The antifreeze/corrosion inhibitor concentra-
tion in the cooling system should:
R be at least 50%. This will protect the cooling
system against freezing down to around
-37 †.
R not exceed 55% (antifreeze protection
down to -45 †); otherwise, heat will not be
effectively dissipated
If the vehicle has lost coolant, top it up with
equal amounts of water and antifreeze/cor-
rosion inhibitor. Mercedes-Benz recom-
mends an antifreeze/corrosion inhibitor
which has been approved for Mercedes-Benz. !
The cooling system contains a supply
which must be renewed after 15 years, or
after 250, 000 km at the latest.
The warranty is only valid if you top up with
an antifreeze/corrosion inhibitor which
has been approved by Mercedes-Benz and
if the recommended mixture ratio is
observed. Brake fluid
Over a period of time, the brake fluid absorbs
moisture from the air; this lowers its boiling
point. G
Risk of accident
If the boiling point of the brake fluid is too low,
vapour pockets may form in the brake system
when the brakes are applied hard (e.g. when
driving downhill). This would impair braking
efficiency.
Have the brake fluid renewed every two years
with a brake fluid that has been approved by
Mercedes-Benz and have this confirmed in
the Service Booklet.
i There is usually a notice in the engine
compartment to remind you when the next
brake fluid change is due. Windscreen washer system
The headlamp cleaning system* and wind-
screen washer system are both supplied from
the washer fluid reservoir.
Further information on windscreen washer
fluid and its mixing ratio ( Ypage 178). Service products and capacities
291Technical data
* optional
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