What's the matter with black floating objects in Lefeng coolant?

For your question, this may be caused by too much scale in the engine cooling system. When you say floating objects, you should mean scales falling off. It is recommended that you clean the water tank and replace the antifreeze as soon as possible. The antifreeze should be replaced when the car is hot. First, open the water tank cover, cover it with a wet cloth and unscrew it (to avoid scalding). Then unscrew the drain screw under the water tank. In order to prevent burns, it is best to wrap the screws with thick cloth. After reaching a certain level, start the engine, let the water pump run, and let the antifreeze in the original car be fully discharged. Insert the tap water pipe into the water inlet and flush the water tank and waterway. At this time, it is also necessary to drive the car to operate. In order to let the water pump help the circulation of water flow, wash the inside of the cooling system more cleanly, and then empty it; At this time, tighten the oil drain plug, pour in new antifreeze, and start the engine again after filling it up, so that the rotation speed is high (about 1500 rpm). Wait for the antifreeze to circulate for a while and then fill it up, which is basically ok. Pour the remaining antifreeze into the water replenishment tank, being careful not to exceed the upper limit, and then put the remaining antifreeze into the trunk for later use. In the choice of antifreeze, we must use the products of big manufacturers to avoid corrosion of engine waterways. I hope my answer is helpful to you.