Yes you can - it's also part of how to bleed the cooling system.
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automatic....engine warm and running while in park, standard, engine off. But this is covered in your owner's manual
The radiator fan is designed to run continuously while the engine is running so that the temperature of the coolant can be lowered. The coolant is continuously run through the engine, collecting engine heat and dispersing it over the radiator fins; while the fan blows the fins and cooling off the coolant before recirculating back through the engine in a continuous cycle.
A coolant leak while the engine is running is likely in the water return hoses. The vehicle can be standing still and in park, but with the engine running the fluids are still being pushed through the system to keep the engine cool. The water return lines generally run from the top left of the radiator when you are standing at the front of the car looking at the engine. Any leak in that system will likely not continue once the engine is stopped as the fluid no longer is pushed through the system.
You have a blown head gasket. Open your radiator while the engine is running. You should find exhaust coming from it.
Simply stated: The coolant system of your car is a pressurized system. When your engine is running it is generating heat causing the coolant to expand. Your radiator cap helps maintain the pressure in your coolant system, without it there the water as it heats will push it's way back out of the system. Even when you have the cap on the pressure will push coolant into the reservoir that is attached to the tube you can find coming out past the cap. When your engine cools the extra coolant is pulled back out of the reservoir into the cooling system. NOTE: You should always use the recommended coolant specified by your car manufacturer, using only water can possibly damage your engine.
To add coolant to and 1985 Mercedes 380se find the reservoir located in the engine bay next to the radiator. Make sure to use the proper mixture of coolant to water ratio and pour until the appropriate level. Overfilling can lead to sprouting a leak while the engine is running.
Water is one of the byproducts of combustion. This usually noticeable when the engine is cold. I had owned a 1995 Sable and now a 2005 Taurus. They both do the same thing when the engine is cold. That is one of the reasons for the stainless steel exhaust that is corrosion resistant.
To bleed the coolant in a 1995 Dodge intrepid locate the drain plug on the underside of the radiator, un plug it and pour new coolant in the system. Close the plug and while the engine is running find the coolant pressure valve and loosen it to relieve pressure. When bubbles stop forming there is no longer air in the system.
the engine is conducting the power to move the car and use oil and gas, while that is hapening, friction is also occoring at the same time therfore causing heat to be exerted. Low or no coolant. Also. if coolant is low on antifreeze, the coolant will freeze and not circulate, causing the engine to run hot while blowing cold air through the heater fan.
If the question is: why does your top radiator hose get soft while the engine is running? If that's what u want to know, it's because the thermostat in the engine opens to flow the coolant thru the motor to keep the operating temperature from getting to hot. It's stores water in the radiator which cools the water and the thermostat blocks it until a predetermined temp.
Let it settle. You maybe fooled about the bubbles if your are checking it while the fluid is hot. At rest with the engine cooled down, there wouldn't be any bubbles. Check the coolant level when engine is cooled off and not running.
If the engine is running and the alternator is good. If the engine is not running, no.