The antifreeze that has just been added turns brown, and the coolant turns to rust. Can it still be used?

The newly added antifreeze turns brown. The reason may be that tap water or inferior antifreeze has been used before, and a certain amount of scale has been generated in the cooling system. When it is replaced with high-quality antifreeze, it contains a certain amount of anti-rust and rust remover. In addition to the penetration function of ethylene glycol, it reacts and removes rust and dirt, so it has become a phenomenon that everyone sees "the antifreeze just added turns brown".

The coolant can still be used if it turns into rusty color. If the rust is serious, after a few days of use, you can drain the old antifreeze and clean the cooling system, and then add new antifreeze.

If there is scale in the cooling system, the heat exchange efficiency of the engine will decrease, the water temperature will rise, and the rubber tube will age. Even when the engine is running at high temperatures, the cylinder head gasket may be broken down and the gap between the piston and the cylinder block may be reduced. The abrasion is intensified, and phenomena such as burning cylinders and lavas appear.

The scale in the cooling system will also cause low-temperature "boiling", and the water temperature will boil at 70-90℃. Even if the antifreeze is added, it may not have a significant inhibitory effect.

Therefore, it is best to use high-quality antifreeze and replace it regularly. In general, the life cycle of antifreeze is about 2 years or 40,000 kilometers, and as a commercial vehicle (taxi), the antifreeze can be replaced once a year. However, this is for reference, and it depends on the actual situation.