Why does the water temperature of Volkswagen LaVida reach 90 degrees in a few minutes?
Why do you need to raise the water temperature to 90 degrees? The engine is assembled by many parts, and the fit clearance between parts should not be too large, otherwise it will not only affect the thermal efficiency of the engine, but also cause problems such as rising fuel consumption, abnormal noise, jitter or oil leakage. Especially, the gap between piston, piston ring and cylinder is too large, which will aggravate their wear and cause oil combustion. Then the problem is that any part will expand when heated and contract when cooled, and its size will change at different temperatures. So how to ensure that they can be seamlessly spliced together at any temperature?
It is obviously unrealistic to ask nature to keep a constant temperature, so we need to artificially create a constant temperature environment for the engine, which can be achieved by coolant. Waterways extending in all directions are designed inside the engine, so that coolant can flow and circulate in it. As long as the temperature of the coolant can remain stable, the working temperature of the engine is basically stable. At present, the common practice of various car companies is to define 90 degrees as the standard temperature of coolant, and engineers also take 90 degrees as a necessary condition when designing engines. The truth is-when the water temperature is 90 degrees, the engine will be in the best working condition.
Why does it have to be 90 degrees instead of 80 or 100 degrees? Not necessarily 90 degrees, but also 80 degrees or 100 degrees, but 90 degrees is the mainstream. The reason is simple, because the main function of coolant is to dissipate heat, so we should make full use of its heat absorption ability. If the temperature is designed too low, it will waste its heat storage capacity, which will inevitably bring greater burden to the radiator and fan. On the contrary, if the temperature design is too high, it will put forward higher requirements for the boiling point of coolant, which will not only increase the cost of building and maintaining cars, but also lead to higher failure rate, so 90 degrees is a gold temperature that is neither too high nor too low. For those performance cars, in order to pursue higher engine combustion efficiency, the water temperature is often higher than that of ordinary family cars, and some can even be as high as 120 degrees.
What do you think of the water temperature? Most models have their own water thermometer on the dashboard, which can be read directly. There are also some models that don't have water temperature meters, but you can manually call out the values. If not, you can explain it, so I won't go into details here. In a word, the water thermometer is still very important. As a car owner, you must learn how to look at it.
How long does it take for the water temperature to reach 90 degrees after the cold car starts? There is no standard answer to this question, because the speed of water temperature rise will be affected by four factors and cannot be generalized.
Factor 1: original residual temperature before engine start. The longer the car is parked, the lower the residual temperature of the engine, so the longer it takes to re-establish the temperature;
Factor 2: Ambient temperature. The lower the ambient temperature, the slower the water temperature rises, and vice versa;
Factor 3: Driving habits after starting. When starting the car at idle speed, the water temperature rises slowly, and when driving directly on the road, the water temperature rises quickly;
Factor 4: Whether the cooling system works normally. There is something wrong with the cooling system of some cars, so the change of water temperature will become abnormal.
Generally speaking, if the ambient temperature of a trouble-free car is neither too hot nor too cold after parking for one night, it will take about 10-20 minutes for the water temperature to reach 90 after starting. If you choose a direct flight, it will only take about 5- 10 minutes.
What faults will cause the water temperature to rise too slowly? Possibility 1: The coolant is overfilled. Too much coolant means more heat is needed for heating, so the heating speed will slow down. When replacing antifreeze, it is recommended that you keep the liquid level within the required range.
Possibility 2: thermostat failure. There is a thermostat in the cooling system, which is actually a valve to control whether the coolant circulates inside the engine or flows to the radiator and fan. If the thermostat is in a normally open state, it will cause the coolant to be continuously sent to the radiator to dissipate heat after the cold car starts, and it is difficult for the water temperature to rise.
Possibility 3: cooling fan failure. If the cooling fan can't stop and is still desperately cooling when it is not needed, then the water temperature will naturally be difficult to rise.
Possibility 4: Water temperature sensor failure. The current engine is highly electrified, and the water temperature is basically monitored by sensors, so if there is something wrong with the sensor itself, the water temperature will naturally get out of control.
In short, if the water temperature can reach 90 degrees within a few minutes after the cold start of the car, it means that it works normally. If the water temperature rises too slowly, or even never reaches 90 degrees, then we should find the reason as soon as possible and prescribe the right medicine.