85 Climate control
Te ch n ica l
data Instruments
and controlsOperationDrivingInstrument
cluster displayPractical hints Car care Index 1Temperature selector, left side passenger
compartment
2Temperature selector, right side passenger
compartment
3Air volume control switch
4Air distribution control switch
5Rear window defroster
6Economy mode
7Air recirculation, Residual engine heat utilization
8Air volume control for center air outlets, turn wheel
up to open.
9Air volume control for side air outlet and side
window defroster outlet, turn wheel up to open.
10Center air outlets, adjustable
11Side air outlet, adjustable
12Windshield air outlet
13Side window defroster outlet, adjustableThe system is always at operational readiness, except
when manually switched off.
The climate control only operates with the engine
running.
The temperature selector should be left at the desired
temperature setting. The temperature selected is
reached as quickly as possible.
The system will not h eat or cool a ny quicker by setting a
higher or lower temperature.
The climate control removes considerable moisture from
the air during operation in the cooling mode. It is
normal for water to drip on the ground through ducts in
the underbody.
89 Climate control
Te ch n ica l
data Instruments
and controlsOperationDrivingInstrument
cluster displayPractical hints Car care Index Air recirculation
This mode can be selected to temporarily reduce the
entry of annoying odors or dust into the vehicle’s
interior.
Outside air is not supplied to the vehicle’s interior.
To select, press O button.
To cancel, press O button again.
The system will automatically switch from recirculated
air to fresh air
•after approximately 5 minutes at outside
temperatures below approximately 40°F (5°C),
•after approximately 30 minutes, at outside
temperatures above approximately 40°F (5°C),
•after approximately 5 minutes, if button S is
pressed.
At high outside temperatures, the system automatically
engages the recirculated air mode for approximately
30 minutes, thereby increasing the cooling capacity
performance. Press O button again to extend the
recirculated air mode.Residual engine heat utilization (REST)
With the engine switched off, it is possible to continue
heating the interior for a short while.
Air volume is controlled automatically. Select
temperature for each side of the passenger
compartment. Set air distribution control switch to the
desired position.
To select:
Turn key in steering lock to position 1 or 0 or remove.
Press O button. Indicator lamp in the button lights
up.
This function selection will not activate if the battery
charge level is insufficient.
To c a n c e l :
Press O button. Indicator lamp in the button goes
out.
The system will automatically shut off
•if you turn key in steering lock to position 2,
•after approximately 30 minutes,
•if the battery voltage drops.
183 Malfunction and indicator lamps
Te ch n ica l
data Instruments
and controlsOperation DrivingInstrument
cluster displayPractical hints Car care Index Low engine coolant level warning lamp
With the key in steering lock position 2, the
warning lamp comes on. It should go out
when the engine is running.
If the warning lamp does not go out after starting the
engine, or if it comes on while driving, then the coolant
level has dropped below the required level. If no leaks
are noticeable and the engine temperature does not
increase, continue to drive to the nearest service station
and have coolant added to the coolant system, see
page 194.
The low engine coolant level warning light should not be
ignored. Extended driving with the light illuminated
may cause serious engine damage not covered by the
Mercedes-Benz Limited Warranty.
In cases of major or frequent minor coolant loss, have
the cooling system checked at your authorized
Mercedes-Benz Center as soon as possible.
Note:
Do not drive without coolant in the cooling system. The
engine will overheat causing major engine damage.Monitor the coolant temperature gauge while driving.
Low windshield and headlamp washer system fluid
level warning lamp
With the key in steering lock position 2, the
warning lamp comes on. It should go out
when the engine is running.
If the warning lamp does not go out after starting the
engine, or if it comes on while driving, the level of the
reservoir has dropped to approximately 1/3 of the total
volume. The reservoir should be refilled with MB
Windshield Washer Concentrate “S” and water (or
commercially available premixed windshield washer
solvent /antifreeze, depending on ambient temperature -
see page 195) at the next opportunity. The reservoir for
the windshield and headlamp washer systems is located
in the engine compartment.
Wa r n i n g !
Do not spill antifreeze on hot engine parts.
Antifreeze contains ethylene glycol which may
burn if it comes into contact with hot engine parts.
You can be seriously burned.
194 Coolant level
Te ch n ica l
data Instruments
and controlsOperation DrivingInstrument
cluster displayPractical hintsCar care Index
Coolant level
To check the coolant level, the vehicle must be parked
on level ground and the engine stopped.
Check coolant level only when coolant is cold.
Adding coolant
If coolant has to be add ed, a 50/50 mix ture of water and
MB anticorrosion / antifreeze should be added. Refill
coolant until the float in the reservoir reaches and
closes the filler opening. Anticorrosion / antifreeze, see page 256. The drain plugs for the cooling system are
located on the right side of the engine block and at the
bottom of the radiator.
P20.20-2052-26
Wa r n i n g !
In order to avoid possible serious burns or injury:
• Use extreme caution when opening the hood if
there are any signs of steam or coolant leaking
from the cooling system, or if the coolant
temperature gauge indicates that the engine is
overheated.• Do not remove pressure cap on coolant
reservoir if engine temperature is above 194°F
(90°C). Allow engine to cool down before
removing cap. The coolant reservoir contains
hot fluid and is under pressure.• Using a rag, slowly open cap approximately
1/2 turn to relieve excess pressure. If opened
immediately, scalding hot fluid and steam will
be blown out under pressure.
• Do not spill antifreeze on hot engine parts.
Antifreeze contains ethylene glycol which may
burn if it comes into contact with hot engine
parts.
252 Fuels, coolants, lubricants etc. - capacities
Te ch n ica l
data Instruments
and controlsOperation DrivingInstrument
cluster displayPractical hints Car care Index
Fuels, coolants, lubricants etc. – capacities
Veh icle c omponents and t heir respec tive lub rica nts mu st ma tch . T herefore u se only brands tested and rec omm end ed
by us. Please refer to the Factory Approved Service Products pamphlet, or inquire at your authorized Mercedes-Benz
Center.
Model Capacity Fuels, coolants, lubricants etc.
Engine with oil filter SLK 230
SLK 3206.1 US qt (5.5 l)
8.5 US qt (8.0 l)Recommended engine oils
Automatic transmission 8.5 US qt (8.0 l) Automatic transmission fluid
Manual transmission SLK 230
SLK 3201.6 US qt (1.5 l)
1.9 US qt (1.8 l)Transmission oil
Rear axle 1.4 US qt (1.3 l) Hypoid gear oil SAE 90, 85 W 90
Power steering approx. 1.1 US qt (1.0 l) MB Power steering fluid
Front wheel hubs approx. 1.5 oz (43 g) each High temperature roller bearing grease
Brake system approx. 0.5 US qt (0.5 l) MB Brake f luid (DOT 4)
Cooling system SLK 230
SLK 320approx. 9.8 US qt (9.3 l)
a p p r ox . 11.8 U S q t ( 11.2 l )MB Anticorrosion / antifreeze
256 Fuels, coolants, lubricants etc. - capacities
Te ch n ica l
data Instruments
and controlsOperation DrivingInstrument
cluster displayPractical hints Car care Index
Gasoline additives
A major concern among engine manufacturers is carbon
build up caused by gasoline. Mercedes-Benz
recommends the use of only quality gasoline containing
additives that prevent the build up of carbon deposits.
After an extended period of using fuels without such
a d d i t i ve s , c a r b o n d e po si t s c a n b u il d u p e s pe c ia l ly o n t h e
intake valves and in the combustion area, leading to
engine performance problems such as:
•warm-up hesitation,
•unstable idle,
•knocking / pinging,
•misfire,
•power loss.
Do not blend other specific fuel additives with fuel.
They only result in unnecessary cost, and may be
harmful to the engine operation.
Damage or malfunctions resulting from poor fuel
quality or from blending specific fuel additives are not
covered by the Mercedes-Benz Limited Warranty.Coolants
The engine coolant is a mixture of water and
anticorrosion / antifreeze, which provides:
•corrosion protection,
•freeze protection,
•boiling protection (by increasing the boiling point).
The cooling system was filled at the factory with a
coolant providing freeze protection to approximately
-22°F (-30°C) and corrosion protection.
If the antifreeze mixture is effective to -22°F (-30°C), the
boiling point of the coolant in the pressurized cooling
system is reached at approximately 266°F (130°C).
The cool ant sol ution must be used yea r round to provide
the necessary corrosion protection and increase in the
boil-over protection. You should have it replaced every
3years.
To provide the important corrosion protection, the
solution must be at least 45% anticorrosion / antifreeze
(equals a freeze protection to approx. - 22 °F [- 30 °C]). If
you use a solution that is more than 55% anticorrosion /
antifreeze (freeze protection to approx. - 49 °F [- 45°C]),
257 Fuels, coolants, lubricants etc. - capacities
Te ch n ica l
data Instruments
and controlsOperation DrivingInstrument
cluster displayPractical hints Car care Index the engine temperature will increase due to the lower
h eat transfer ca pa bil ity of th e sol ution. Therefore, d o not
use more than this amount of anticorrosion / antifreeze.
If the coolant level is low, water and MB anticorrosion /
antifreeze should be used to bring it up to the proper
level (have cooling system checked for signs of leakage).
The water in the cooling system must meet minimum
requirements, which are usually satisfied by normal
drinking water. If your are not sure about the water
quality, consult your authorized Mercedes-Benz Center.
Anticorrosion / antifreeze
Your vehicle contains a number of aluminum parts. The
use of aluminum components in motor vehicle engines
necessitates that anticorrosion / antifreeze coolant used
in such e ng ines b e specif ica lly formul ated to protec t th e
aluminum parts. (Failure to use such anticorrosion /
antifreeze coolant will result in a significantly
shortened service life.)
Therefore the following product is strongly
recommended for use in your vehicle: Mercedes-Benz
Anticorrosion / Antifreeze Agent.Before the start of the winter season (or once a year in
the hot southern regions), you should have the
anticorrosion / antifreeze concentration checked. The
coolant is also regularly checked each time you bring
your vehicle to your authorized Mercedes-Benz Center
for service.
Anticorrosion / antifreeze quantity
Model Approx. freeze protection
– 35°F
(– 37°C)– 49°F
(– 45°C)
SLK 230 KOMPRESSOR 4.9 US qt
(4.7 l)5.4 US qt
(5.1 l)
SLK 320 5.9 US qt
(5.6 l)6.5 US qt
(6.2 l)