Mercedes S-class W202

1993-2000 of release

Repair and car operation



Mercedes W202
+ 1.2. The general data
+ 2. Maintenance service
+ 3. Engines
+ 4. Greasing system
- 5. Cooling system
   + 5.2. A cooling liquid
   5.3. Antifreeze for a radiator
   5.4. A temperature regulator of a cooling liquid (thermostat)
   5.5. Check of system of cooling
   5.6. Hydraulic муфта the fan
   5.7. The pump of system of liquid cooling
   5.8. A radiator
   5.9. A fan casing
   5.10. Diagnostics of malfunctions of system of cooling
   5.11. Diagnostics of malfunctions of system of indication of level of a liquid
   5.12. An engine overheat
+ 6. Heating, ventilation
+ 7. Ignition system
+ 8. Fuel system
+ 9. Transmission
+ 10. A running gear
+ 11. A steering
+ 12. Brake system
+ 13. A body
+ 14. An electric equipment
+ 14.2. Electroschemes











5.12. An engine overheat
THE GENERAL DATA

Many drivers face necessity of expensive repair though it could be avoided, in due time having paid attention to first signs of approaching breakage. The most typical example of similar refusal is breakage of the gear belt which timely replacement hardly probable costs more expensively $100, and here elimination of consequences of its breakage – $800-3000.

Some owners who in time have guessed "agonal rattles" car, aspire to sell it as soon as possible. The people who have forgotten Pushkin "become their victims, as a rule, you would not chase, the priest, cheapness". As a result of such buyer if will not have an accident during the nearest time after purchase serious expensive repair will be compelled to pay.

To skilled drivers the resulted information will seem to the trivial. However to the great bulk of the motorists which have not passed "autouniversities", driving to "a characteristic crash" is peculiar.

How to avoid the pitiable ending? Today we will stop on possibility of an engine failure and we will talk about one of signs of such situation – an overheat. And it is not casual. Ahead hot summer. And, as practice testifies, in most cases an original cause of failure of the engine at this time year is its overheat. Insidiousness of an overheat that, as a rule, results affect far not at once, but affect always. And if not to accept urgent measures, overheat consequences will inevitably lead to serious refusals, and even at all to an engine exit out of operation. All this way accurately shares on four stages.

The first stage – occurrence of the reasons of an overheat. As a rule, it:

 – подтекание a cooling liquid with the subsequent decrease in level below the top branch pipe of a radiator and, as consequence, the termination of circulation of a liquid in a radiator and formation of an air stopper;
 – Belt easing, failure or the engine of the fan, or the gauge of inclusion of the engine of the fan, or вискомуфты the fan;
 – Wrong adjustment of a corner of an advancing of ignition;
 – High degree нагарообразования in the combustion chamber;
 – A contamination of honeycombs of radiator.

The second stage – directly overheat. Most often it is shown at expectation in traffic jams and engine work on single turns. There is it so: the driver sees that the arrow of the index of temperature starts to move towards a red zone, but believes that while this arrow is not has reached it – anything terrible is not present. It is the first and main error.

The monitoring system of temperature of the engine rather инерционна. The gauge of measurement of temperature is in a water shirt of the massive block of the cylinders having the big capacity. So, temperature in the block of cylinders at occurrence of a leak of a cooling liquid and displacement of its level it will be essential below temperature in a block head. Formation of an air stopper in a radiator and liquid boiling up lead to that the block head practically remains without cooling. That it means, it is clear to everyone. But the driver at the best, a few being nervous, it is mown on an arrow and continues to heat the engine. And further, depending on overheat degree, there come accordingly the third and fourth stages.

During the third stage the engine continues to be heated. And it is good, if business comes to an end with failure of epiploons of valves. And that after all linings of a head of the block can "be covered", and the situation will smoothly pass in the fourth, finishing stage.

It is necessary to allocate it especially. After all if consequences of the previous stages of an overheat can be corrected in one way or another within the limits of average repair the fourth stage assumes irreversible destructions:

 – An overheat and breakage of rings with задиром cylinders;
 – Hit of a cooling liquid in oil and, as consequence, teases of necks коленвала;
 – Deformation of a head of the block;
 – Formation of cracks in a head of the block and the block.

The statistics allows to allocate marks of cars, the most vulnerable to an overheat and more often others "reaching" the fourth stage. Cars Saab "are in the lead" here, and with the big separation. Their forced engines with the minimum backlashes do not forgive Russian "perhaps". Our admirers of this model consider shameful to appear on a tow and more likely will ruin the engine, than will ask to drag their car from a stopper to car-care centre. And as soon as the stop reason – "stopper" – will resolve also owner Saab will press on a gas pedal that with proslipping to break away from other cars, the rests of the antifreeze cooled in a radiator will rush in the heated head and the block, which from similar rudeness will not find anything the best how to burst.

Engines of cars of other marks though "are not so gentle", but also do not forgive the inattentive relation to them. Therefore, to keep the personal estate and purse contents, it is necessary to remember unequivocally: the overheat never happens casual and never remains without consequences. And if you have found out the tendency to an overheat of the engine of your car, immediately stop operation before finding-out of the reasons.