Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Cooling System, Checking Freeze Protection And Coolant Level: Notes
Due to the tap water content differences by country and region, demineralized, deionised, distilled water must be used to mix coolant concentrate.
Use only coolant additives approved for the vehicle. Refer to Electronic Parts information (ETKA). Using other coolant additives can impair the corrosion protection. Loss of coolant can cause considerable damage to the engine.
Coolant in the correct mixing ratio prevents freezing and corrosion damage as well as calcification. The boiling temperature is also increased. For these reasons the cooling system must have coolant additive the whole year.
Especially in countries with tropical climates or when vehicle is driven under heavy engine load, the coolant improves the engine reliability by its increased boiling point.
To determine the current freeze protection value, use the Refractometer :T10007A or Analog Refractometer :T10007B .
The scale -1- on the refractometer refers to the G12++ and G12evo coolant additives.
The scale -2- on the refractometer refers to the G13 coolant additive.
If more than one type of coolant additive has been used, use the scale for G13 to determine the frost protection.
The freeze protection must be set to minimum -25 °C (-13 °F), for countries with an arctic climate, it must be set to approximately -36 °C (-32.8 °F). The freeze protection can be increased only when a stronger freeze protection is required due to climatic conditions. But only down to -52 °C (-61.6 °F), otherwise the cooling effect of the coolant will be impaired.
The coolant concentration must not be reduced by adding water, even during the warmer season or in warm countries. The freeze protection must be a minimum of -25 °C (-13 °F).
The temperature on the Refractometer corresponds to the >>crystallization point<<. At this temperature, ice crystals may begin to form in the coolant.
Used coolant cannot be used again.
Only use water/coolant additive to lubricate the coolant hoses.
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.