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Autopapyrus · Hyundai Sonata 2.0 G4KD (2011)
https://autopapyrus.com/guides/hyundai/sonata/coolant-replacement-yf-2011/
Compiled automatically from service literature and owner experience. Specs are for the typical configuration — check them against your exact car before you start.

Hyundai Sonata 2.0 G4KD (2011): Coolant Replacement

On the G4KD, change the coolant about every 60,000 km or 4 years. The system capacity is about 6.4-6.5 L (6.8-6.9 qt). The old coolant is drained through the radiator. The main difficulty is fully removing air from the system after refilling.

Difficulty: Easy Time: 1-1.5 hours Steps: 13 Tools: Drain container of 8-10 L (8.5-10.5 qt), funnel, flat-blade screwdriver or pliers (for the hose clamp), pliers, gloves, distilled water for flushing, wrench or socket for the drain plug if needed

Parts

2
  • 🔩 Long-life ethylene glycol coolant meeting Hyundai/Kia specification (pink or red in color, class G12+). About 6.5 L (6.9 qt) is needed
  • 🔩 it is best to buy 7-8 L (7.4-8.5 qt) to have a reserve. Premixed 50/50 or concentrate (4-5 L / 4.2-5.3 qt) plus distilled water can be used. A radiator drain plug gasket or O-ring is needed only if worn
There's a full repair manual for this car Every system, wiring diagrams and torque specs — not just this job. Chilton and 5 more. See manuals →

Step by step

13 steps
  1. Work only on a completely cold engine. Park the car on level ground and, if necessary, raise the front end on a lift or jack stands. Open the hood.
  2. Remove the lower plastic engine undercover if it prevents access to the lower radiator hose and the radiator.
  3. Place the container under the radiator. Open the radiator cap and the reservoir cap so air can enter the system. Turn the ignition on without starting the engine, set the heater control to maximum heat and open the heater valves. This lets the coolant drain from the heater circuit as well.
  4. Open the drain plug at the bottom of the radiator. If the plug will not turn or is not accessible, remove the lower radiator hose: loosen the clamp and carefully pull the hose off. Wait until all the coolant has drained.
  5. Drain the remainder from the expansion tank. To do this, remove the tank or pump the coolant out with a bulb or syringe. Wipe the tank and check it for sediment.
  6. If rust or sediment is visible in the old coolant, flush the system with distilled water. Fill with water, warm up the engine with the heater on until the thermostat opens, stop the engine and drain. Repeat until clean water comes out of the system. Do not use tap water: it leaves scale.
  7. Close the drain plug or reinstall the hose and tighten the clamp. Tighten the plug moderately, without much force: it is plastic or sits in a thin radiator housing, and the threads are easy to strip.
  8. If you are using concentrate, dilute it 1:1 with distilled water beforehand. This suits most winters. For very low temperatures the share of antifreeze can be higher, but no more than 60-65%.
  9. Slowly pour the coolant into the radiator up to the neck, then top up the reservoir to the MAX mark. Pour in a thin stream so that air pockets do not form.
  10. Close the radiator cap and leave the reservoir cap open. Start the engine, set the heater to maximum and hold the engine speed at 2000-2500 rpm. Watch the level in the reservoir and add coolant as the air escapes. Continue until the thermostat opens: the upper radiator hose becomes hot and the fan switches on.
  11. Rev the engine several times. Periodically squeeze the upper and lower hoses by hand to push out air. When bubbles stop coming from the reservoir and the heater blows evenly hot, close the reservoir cap.
  12. Stop the engine and let it cool down completely. Check the level, top up to the MAX mark if necessary, and make sure there are no leaks at the plug, clamps and hoses.
  13. After 2-3 trips, check the level on a cold engine and top up if necessary. Reinstall the engine undercover.

Common mistakes and warnings

  • Do not open the radiator cap on a hot engine: a burst of steam and coolant causes severe burns. Antifreeze is toxic, so do not leave it on the ground, and take the used coolant to a recycling facility. Do not mix coolants of different types and colors. Overheating caused by an air pocket is dangerous for the cylinder head, so if the temperature rises, stop the engine immediately and repeat the bleeding. Check the exact torque values for the plug and clamps against the manufacturer's service manual.
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