Coolant plays a key role in maintaining engine temperature and preventing overheating to extend engine performance and life. Volvo Penta coolant, also known as Volvo Penta VCS (Volvo Coolant Specification), has the following performance characteristics to help ensure the efficient operation of marine engines.

1. Advanced anti-corrosion protection, effectively resisting metal corrosion, rust and clogging, ensuring smooth engine operation and extending service life.

2. Excellent thermal conductivity, which can quickly transfer the heat generated inside the engine to the cooling system, helping to maintain the engine operating within the appropriate operating temperature range, improve combustion efficiency, and reduce the risk of engine overheating.

3. High temperature stability, able to maintain its performance under extreme environmental conditions. Whether in hot environments or extremely cold polar regions, it can effectively protect the engine from temperature changes.

Volvo Penta Coolant – Green vs Yellow (VCS)

Volvo Penta currently has two different coolants, green coolant and yellow coolant. Green coolant was used in early products, and all later products shipped from the factory were yellow coolant. Green coolant is produced using different technologies and contains inhibitors that cannot chemically mix with yellow coolant. It is difficult to completely remove the residue of green coolant, so those who originally used green coolant should still use the original coolant, and green coolant must not be mixed with yellow coolant.

Yellow coolant is a yellow liquid. Yellow coolant contains new inhibitory materials adapted to modern engines. It can better prevent corrosion and sediment accumulation, and hinder the occurrence of cavitation and electrical corrosion.

VCS yellow coolant cannot be mixed with green coolant or other brands of engine coolant under any circumstances to avoid possible chemical reactions, clogging of water channels, and high temperatures.

How to Use Coolant?

The replacement cycle is 4 years or 8000 hours. Generally, yellow coolant needs to be replaced every four years, and green coolant needs to be replaced every two years.

Volvo Penta currently provides two types of coolant: mixed liquid or concentrated liquid. The original mixed liquid is composed of 40% concentrated liquid and 60% distilled water; if you need to choose concentrated liquid, the water quality must meet the specifications of ASTM D4985 (American Society for Testing and Materials, abbreviated as ASTM, is a specification developed by the American Society for Testing and Materials, which is specifically used for the evaluation and testing of coolants.), the concentrate must be mixed with purified water according to the mixing ratio, only such coolants are suitable and approved by Volvo Penta.

In order for the cooling system to have a satisfactory anti-rust function, even without any risk of freezing, it is necessary to use coolant with the correct composition all year round. If an unsuitable coolant is used or the coolant is not mixed as required, it will affect the engine in the future. Warranty claims for components of the cooling system may be denied.

Currently, the concentrate has the following three different mixing ratios, which correspond to different freezing points:

40% concentrate and 60% distilled water -24 °C
50% concentrate and 50% distilled water -37 °C
60% concentrate and 40% distilled water -46°C

According to the usage requirements in the user manual, the normal coolant level must be between the upper and lower scale marks of the expansion tank or not lower than the lowest scale. After the coolant is used for a period of time, a small amount of water will evaporate and need to be replenished. If the water quality replenished by the user is inappropriate, it will also cause failure of the related cooling system.

As shown in the picture below, the iron bars in the water tank are oxidized, and the rust peels off and floods every corner of the cooling system. The reason is that the user added a large amount of substandard water. Judging from the rust pictures, rust has been scattered in the cooling system. There is also rust on the engine thermostat mounting base. The engine block and cylinder head are also victims. It is certain that the yellow VCS antifreeze has deteriorated and lost its anti-rust function. One of the basic functions of qualified antifreeze is to prevent rust. It is the user’s responsibility to use qualified and regular coolant.

How to Purchase Volvo Penta Coolant?We currently offer Coolant VCS (yellow) as a stock solution in a 5-liter concentrated form, which can be conveniently purchased directly through our online store. It is important to note that before use, the coolant must be diluted with distilled water. Please avoid using tap water or mineral water for dilution purposes.