Note. The procedures for checking the fluid level are described below, carried out every 400 km or weekly. A description of other fluid level checks can be found later in the Sections on specific maintenance procedures. Regardless of the scheduled inspection intervals, do not allow fluid to leak under the vehicle - such leaks indicate a malfunction that should be repaired immediately.
Attention! When checking the level of any working fluid, the car must be located strictly horizontally!
Fluids are an integral part of the lubrication, cooling, brake and windshield washer systems. Due to the gradual consumption and / or contamination of fluids during normal vehicle operation, they should be replaced periodically. Before adding fluid to any of the listed components, study the requirements Specifications to the types and volumes of fluids used.
Engine oil
Visual control of leaks
With an oily engine and high oil consumption, check the areas most likely to develop leaks:
- The sealing element of the filler cap, - check for cracks and other mechanical damage;
- Components of the crankcase ventilation system (in particular - the ventilation hose from the cylinder head cover to the air intake hose);
- Cylinder head cover gasket;
- Cylinder head gasket;
- Sealing ring of a drain stopper of the pallet of a crankcase of the engine;
- Oil filter gasket, - carefully examine the place where the filter fits on the flange;
- Oil pan gasket.
- Front and rear crankshaft seals.
Wrap the alternator in plastic, spray the engine with a normal cold cleaner, - then, after a short time - wash it with water at a car wash.
Sprinkle the joints of the mating surfaces and the sealing elements of the power unit with lime or talc from the outside.
Check oil level, top up if necessary.
During a short (about 30 km) travel (preferably on the highway) warm up the engine - warm oil is characterized by increased fluidity and seeps through leaks more easily.
Park the car and, highlighting yourself with a lamp, examine the engine in order to localize the sources of oil leaks.
Eliminate the causes of the development of leaks.
Level check
Note. The maximum allowable consumption of engine oil is 1l/1000 km, the actual level of oil consumption depends on the manner - frequent driving at high engine speeds leads to an increase in oil consumption.
Note. Information on the principle of operation of the engine oil level warning lamp is given in Section Instrument cluster, meters and control lamps and indicator lights Chapters Manual
A warning lamp built into the ignition switch assembly warns of a dangerous drop in the driver's engine oil level (see Section Instrument cluster, meters and control lamps and light indicators Chapters Operation manual). The oil level switch is located under the vehicle, in the right front corner of the engine sump.
Location of the filler neck and dipstick for measuring the level of impellent oil on models S280 and S320
1 - Probe
Location of the filler neck and dipstick for measuring the level of impellent oil on S300TDI models
1 - Neck
2 - Probe
Location of the filler neck and dipstick for measuring the level of impellent oil on the S420 and S500 models
1 - Probe
2 - Neck
Location of the filler neck and dipstick for measuring the level of impellent oil on S600 models
1 - Probe
2 - Neck
Checking the level of impellent oil is carried out using a dipstick threaded into the guide tube and lowered into the engine to the lowest point of its oil pan. The oil level should be checked before the first trip of the day, or about 5 minutes after the engine has been stopped. If the check is performed immediately after turning off the engine, the results will not adequately reflect the situation, as part of the oil will be distributed to the internal galleries and engine components.
Remove the dipstick from the guide tube and dry its blade with a clean cloth or paper towel. Insert the dipstick back into the tube until it stops, then remove it again. After examining the probe blade, estimate the size of the area wetted with oil. The oil level should be between the upper and lower marks on the dipstick blade. If necessary, top up the engine with the appropriate amount of oil of the required grade.
Lowering the level beyond the lower limit of the permissible range leads to the development of engine oil starvation, which is fraught with serious mechanical damage to the latter. Try also not to overfill the oil above the upper mark, as this can lead to throwing spark plugs or failure of the power unit seals as a result of excessive pressure buildup.
In order to fill the engine with oil, it is necessary to remove the threaded filler cap. Use a funnel or an oil can with a long spout to avoid splashing oil when filling it into the engine. After filling in oil, screw on and firmly tighten the filler cap, then start the engine and carefully inspect the drain plug and the surface of the oil filter mating with the block for signs of leakage.
Stop the engine, wait 5-10 minutes for the oil to drain into the sump, then check the level again.
Note. Excess oil must be drained or pumped out - an excessive level of impellent oil can cause failure of the catalytic converter. Track reliability of a tightening of a cover of a jellied mouth.
Checking the engine oil level is an important preventative engine maintenance procedure. A constantly low level indicates the presence of oil leaks as a result of failed oil seals, damaged seals, worn piston rings or valve guides. If the oil resembles milk in color or consistency, or there are drops of water in it, this indicates a possible damage to the cylinder head gasket, or the formation of cracks in the body of the head (OK) or block. The check must be made without delay. When measuring the oil level, always also check its condition. Using your thumb and forefinger, remove traces of oil from the dipstick blade - if there are small metal particles in it, the oil must be replaced (see Section Changing the engine oil and oil filter).
Engine coolant
Attention! Do not allow antifreeze to come into contact with exposed areas of the body and painted surfaces of the car.
Wash off accidental splashes with plenty of water without delay.
Remember that antifreeze is a highly toxic liquid and getting it into the body, even in small quantities, is fraught with the most serious consequences, even death.
Never leave antifreeze stored in a loosely closed container, immediately collect spilled coolant on the floor.
Remember that the sweet smell of antifreeze can attract the attention of children and animals.
Consult with local authorities about ways to dispose of used coolant - in many regions of the world there are special points for receiving various kinds of waste.
Never drain old coolant down the drain and onto the ground!
Note. Recently, non-toxic grades of antifreeze have been developed, however, they must also be disposed of in an organized manner.
All vehicles covered in this manual are equipped with an overpressure compensation type cooling system. The white plastic expansion tank is located in the engine compartment and is connected by a hose to the radiator.
As the engine warms up during operation, the expanding coolant fills the reservoir. When the engine cools down, the coolant automatically flows back into the cooling system, which maintains a constant value of its level. A warning lamp included in the instrument cluster warns the driver of a dangerous drop in the coolant level (see Section Instrument cluster, meters and control lamps and indicator lights Chapters Manual). The coolant level switch is located at the bottom of the expansion tank of the cooling system.
Checking the coolant level in the reservoir should be done regularly, with the vehicle in a strictly horizontal position and the engine off. In the cold state of the coolant, its level should reach the mark «MIN» in the expansion tank. When the coolant is hot, the level should be about 1.5 cm higher. Adjust if necessary - add 40%/60% ethylene glycol based antifreeze with water (see Specifications).
Drive the car and measure the coolant level again. If only a small amount of coolant needs to be added to the correct level, clean water can be used for this. However, frequent additions of water will dilute the antifreeze. In order to ensure the correct ratio of antifreeze and water, always top up to the correct level with the required mixture.
If the coolant level drops regularly, there may be a leak in the system. Inspect the radiator, hoses, filler cap, drain plugs and water pump (refer to section Checking the functioning of the cooling system and frost resistance of the coolant, changing the fluid). If no leaks are found, have the expansion tank cap and radiator leak tested in a workshop.
If you need to remove the cover, wait until the engine is completely cool, then wrap a piece of thick rag around the cover and unscrew it to the first stop. If steam or coolant starts to escape from the cap, allow the engine to cool slightly before removing the cap.
You should also check the condition of the coolant. It should be relatively clean. If the fluid is brown or rusty in color, it must be drained, the system flushed and filled with new mixture. Even if the coolant looks normal, the corrosion inhibitors it contains lose their effectiveness over time, so it should be replaced at regular intervals.
To check the frost resistance of the coolant, you must use a hydrometer.
Brake fluid
Attention! Brake fluid can harm your eyes and damage the painted surfaces of your vehicle, so be very careful when handling it. Do not use brake fluid that has been exposed for a long time or is more than one year old. Brake fluid tends to absorb moisture from the air, which can lead to a dangerous loss of brake system performance. Use only the recommended type of brake fluid. Mixing different types of fluid can cause brake system failure.
The master cylinder of the brake system is installed in the rear left corner of the engine compartment. A drop in the driver's brake fluid level is warned by the operation of a warning lamp built into the instrument cluster (see Section Instrument cluster, meters and control lamps and indicator lights in Chapter Manual) the float switch of which is built into the cover of the GTZ tank.
The brake fluid level is checked visually, according to the marks on the plastic reservoir mounted on the master cylinder. The fluid level must be between the marks «MAX» And «MIN». If the level is too low, first wipe the top of the reservoir and the lid with a clean rag to prevent dirt from entering the system after removing the lid. Top up to the correct level with the recommended fluid, but do not overfill.
While the reservoir cap is off, check the fluid and master cylinder reservoir for contamination. If it contains particles of rust, dirt or drops of water, the fluid from the system should be drained and filled with new.
After filling the reservoir to the correct level, make sure that the lid is installed evenly to avoid fluid leakage and / or dirt ingress.
The fluid level in the master cylinder will drop slightly as a result of worn brake pads. There is no need to add it as long as the level remains near the mark «MIN»; it will rise after changing the pads. A very low level may indicate worn brake pads. Check them for wear (see Section Checking the brake system).
If the brake fluid level keeps dropping, check the entire system for leaks immediately. Inspect brake lines, hoses and fittings, along with calipers, wheel cylinders and master cylinder (refer to Sections Checking the brake system, Checking the condition and replacing the engine compartment hoses, localizing leaks).
If the reservoir is empty or nearly empty when checking the fluid level, the brake system must be checked for leaks and bled (refer to chapters Clutch and Brake system).
Power steering fluid (power steering)
Attention! If the fluid level in the reservoir has dropped below the fluid temperature zone, the hydraulic power steering should be checked by a specialist workshop because there is fluid loss. In this case, it is not enough to limit yourself to just adding the liquid level.
Checking the power steering fluid level on models equipped with 104 and 119 series engines
30 - Power Steering Reservoir
30s - Plastic pointer
Checking the power steering fluid level is carried out at a temperature of about 20°C. The fluid level must be between the marks «MIN» And «MAX» plastic tank gauge/ (except models equipped with 120 series engines) / blades of the measuring probe mounted in the cover of the tank (models with 120 series engines). The total volume of the tank is 1.4 liters.
Note. Information on adjusting the power steering fluid level for diesel models at the time of this Manual was not provided by manufacturers, the principle is similar to one of those described above for gasoline engines.
Windshield/Headlight Washer Fluid
Attention! Windshield washer concentrate is highly flammable! Do not use fire, open flames or smoking when handling windshield washer concentrate.
The windshield washer fluid is contained in a plastic reservoir in the right front corner of the engine compartment. The filler neck of the tank is brought out into the front panel and is located between the right headlight and the radiator. Tank capacity is given in Specifications.
A drop in the driver's coolant level is warned by the operation of a warning lamp built into the instrument cluster (see Section Instrument cluster, meters and control lamps and light indicators Chapters Operation manual). The indicator switch is mounted on the top of the coolant reservoir.
In temperate climates, the system can be filled with normal water, but it is recommended to add glass cleaner to the water (summer MW concentrate is labeled S). The tank should be no more than two-thirds full, so that there is free space in case the water expands when it freezes. In areas with cold climates, a special windshield washer concentrate should be used (W marking), which lowers the freezing point of the liquid, which can be purchased at any auto accessories store. It is usually sold in concentrated or prepared form. If you purchased concentrated antifreeze, mix it with water according to the manufacturer's instructions on the package.
Attention! Do not use antifreeze in the cooling system - it will damage the painted surfaces of the car!