Attention! Allow the engine to cool before starting this work. Do not allow antifreeze to come into contact with skin or painted body surfaces. Wash off spilled liquid immediately with plenty of water. Do not leave antifreeze on the floor in an open container.
1. With the engine cold, wrap a thick rag around the cap of the expansion tank and turn the cap counterclockwise. A whistling sound is heard - the pressures in the cooling system are equalizing with atmospheric pressure. When the hissing stops, turn the plug all the way and remove it.
2. Remove the air bleed screw from the hose connection above the expansion tank. On some models, the air bleed screw is located next to the oil filter cover (pic. 25.2, a, b).
3. Remove the crankcase protection from under the engine (pic. 25.3).
4. Place containers under the radiator drain plug and under the expansion tank. Loosen the drain plugs and let the fluid drain into a container (pic. 25.4, a, b).
5. To completely drain the fluid, also unscrew the drain plug on the right side of the cylinder block and let the remaining fluid drain into a container. The 4-cylinder N42 engine has a second drain plug on the left side of the cylinder block (pic. 25.5.a, b).
6. If the fluid was drained not for replacement, but for another reason, it can be used again if it is less than two years old (although it is not recommended).
7. When all the liquid has flowed out, tighten the air bleed screws, replace the sealing washers on the cylinder block plugs, and screw in the plugs.
Flushing the cooling system
8. If the coolant has not been changed for a long time or if it is diluted with water, then over time the cooling system may lose its effectiveness as the system channels become corroded, sludge and deposits. The efficiency of the cooling system can be restored by flushing.
9. The radiator should be flushed separately from the engine to prevent excess contamination.
Flushing the radiator
10. To flush the radiator, disconnect the upper and lower hoses from it, as well as all other hoses, if any (see chapter 3).
11. Insert a garden hose into the top radiator hose and turn on the water so that the water circulates through the radiator. Continue flushing until clean water flows from the lower nozzle.
12. If, after sufficient time, the water coming out is still not clean, flush the radiator with a neutral detergent designed for cooling systems. Follow the detergent manufacturer's instructions. If the radiator is very dirty, flush it in the opposite direction by inserting the hose into the lower connection.
Engine flush
13. Before flushing the engine, remove the thermostat from it, as indicated in chapter 3, then temporarily reinstall the thermostat cover.
14. Disconnect the upper and lower hoses from the radiator. Insert a garden hose into the top radiator hose and open the water.
Flush the engine until clean water flows from the lower radiator hose.
15. When flushing is complete, replace the thermostat and connect the hoses (see chapter 3).
Filling the cooling system
16. Before filling the cooling system, check that all hoses and clamps are in place and in good condition. Check that the clamps are securely tightened and that the drain plugs of the radiator and cylinder block are screwed into place. Keep in mind that antifreeze should be used all year round. and not only in cold weather, since the additives contained in it prevent corrosion of the internal surfaces of the engine water jacket.
17. Loosen the screws to bleed air from the cooling system (ohm. rice. 25.2, a, b).
18. Turn on the ignition and set the heater control to the maximum temperature position, and the fan speed to the minimum position. This will open the heater valve.
19. Remove the expansion tank cap. Pour the coolant into the reservoir slowly to avoid air pockets.
20. When changing the fluid, first pour a couple of liters of water into the system, and then add the required amount of pure antifreeze. Bring the amount of fluid to the required level by refilling the system with clean water.
21. When liquid flows from under the bleed screws without air bubbles, screw in and tighten the screws securely.
22. When the fluid level in the expansion tank begins to rise, squeeze and release the upper and lower radiator hoses to push any air pockets out of the system. If after this operation the liquid level in the tank has dropped, bring it to the MAX mark and tighten the plug of the expansion tank.
23. Start the engine, warm up to operating temperature, then turn off and let cool.
24. With the engine running, check all disturbed areas for leaks. With the engine cold, check the fluid level in the expansion tank and top up if necessary. We draw your attention to that. that the level marks correspond to a cold engine. If the expansion tank needs to be opened when the engine is still warm, cover the tank cap with a thick cloth to prevent scalding from the steam coming out of the tank. Unscrew the plug a little until a hissing sound appears and let the pressure inside the cooling system equalize with atmospheric pressure. When the hissing stops, unscrew the plug all the way.
Coolant
25. Coolant should be changed at regular intervals. This must be done because the antifreeze contained in it loses its protective properties over time and corrosion can begin in the engine water jacket.
26. Use an ethylene glycol based antifreeze to prepare the coolant, which is best suited for multi-metal cooling systems. The capacity of the cooling system and the percentage composition of the coolant are given in the Technical data at the beginning of this chapter.
27. Before filling the system with fresh coolant, the old coolant must be completely drained and the cooling system flushed. At the same time, you should check the condition of all hoses of the cooling system and the reliability of their fastening with clamps.
28. After replacing the coolant, attach a plate to the expansion tank with the date of filling, type and concentration of antifreeze. Until the next replacement, only the same liquid should be added to the system.
29. Never use antifreeze to refill the windshield washer reservoir, as antifreeze will ruin the body color. For washer there are special additives.