Refrigerant Oil
WARNING: This page is about a different car, the 2022 Volkswagen ID.4 and 2021 Volkswagen ID.4. However, it is still accessible from the selected car via links, so may be relevant.
CAUTION:
Risk of acid burns due to atomized refrigerant oil. Eye or other body injury possible.
- Wear safety gloves.
- Wear protective eyewear.
- Never breath in atomized refrigerant oil.
- Refrigerant oil mixes with the refrigerant (about 10 to 40%, depending on compressor type and refrigerant quantity), circulates continuously in the circuit and lubricates the moving parts.
- In connection with R744 A/C systems, special synthetic refrigerant oils, such as polyalkylene glycol (PAG) oil, are used with specific additives that match the refrigerant. This is necessary because, for example, mineral oil does not mix with R744, and undesirable reactions with the refrigerant or the refrigerant circuit components may occur when these additives are missing. In addition, the components of the R744 A/C system could be affected if the mixture flows through the refrigerant circuit under pressure at high temperatures or the lubricating film in the A/C compressor tears. The use of non-approved oils can lead to the failure of the A/C system and exclusive use is therefore to be made of authorized refrigerant oils. Refer to the Parts Information.
- Types of oil for refrigerant R744 in motor vehicles: PAG oil with specific additives that match refrigerant R744 (polyalkylene glycol with specific additives).
- The most important characteristics are the high degree of solubility with refrigerant, good lubrication, no acid content, very minimal water content, and suitability for high temperatures during A/C system operation. For this reason only very specific oils may be used. Refer to the Parts Information and Technical Data (vehicle-specific repair information) for a list of the approved refrigerant oils and capacities.
- PAG oils that are suited for refrigerant R744 are highly hygroscopic and cannot always be mixed with other oils. Therefore only use approved refrigerant oils. Refer to the Parts Information.
- Moisture and acids promote aging of refrigerant oil, causing it to become dark and viscous as well as corrosive towards metals. For this reason close containers with refrigerant oil to protect it from moisture, immediately seal opened containers.
- Refrigerant oil, because of its chemical properties, must not be disposed of with engine oils or transmission oils. Dispose of refrigerant oil as a used oil of unknown origin (pay attention to local regulations).
- For refrigerant R744 circuits, only use the oil approved for this refrigerant and the A/C compressor installed. Refer to the Parts Information.
- Refrigerant oil that was developed for refrigerants other than refrigerant R744 (such as refrigerant R134a or R1234yf) is not suitable for refrigerant circuits with refrigerant R744 (certain additives are missing, they are not designed for the higher temperatures in the R744 refrigerant circuit, etc.). For this reason, also pay attention to the correct version. Refer to the Parts Information and TECHNICAL DATA (vehicle-specific repair information).
- Do not use ester-based oils (POE oils). These are currently only for larger systems under different operating conditions (not for vehicle A/C systems with R744).
- Do not store open containers of refrigerant oil because it is hygroscopic (attracts moisture).
- Always keep containers with refrigerant oil and the refrigerant circuit closed.
- The specification about the usability of the refrigerant oil is given on the bottle the refrigerant oil is delivered in.
- This time specification does not need to be observed when the delivered bottle is tightly sealed.
- Refrigerant oil from a tightly sealed bottle can also be used after the time specified on the bottle.