I assume you mean the cooling system overflow reservoir is emptying out and you need to keep topping up the coolant level.
This means you either have an external leak or internal leak in the cooling system. Yes that is a big concern because the cooling system is critical for your engine. There can be numerous causes and you need to have the loss of coolant investigated. If the cooling system loses fluid as it is doing your engine can overheat and if this occurs you will experience very expensive engine damage. So have it checked out by a professional very soon. In the meantime ensure that the cooling system is topped up to the correct level and monitor the coolant temperature gauge on your instrument panel which should stay below the half way mark.
Answers & Comments
Which reservoir? windshield fluid, coolant, brake?
I assume you mean the cooling system overflow reservoir is emptying out and you need to keep topping up the coolant level.
This means you either have an external leak or internal leak in the cooling system. Yes that is a big concern because the cooling system is critical for your engine. There can be numerous causes and you need to have the loss of coolant investigated. If the cooling system loses fluid as it is doing your engine can overheat and if this occurs you will experience very expensive engine damage. So have it checked out by a professional very soon. In the meantime ensure that the cooling system is topped up to the correct level and monitor the coolant temperature gauge on your instrument panel which should stay below the half way mark.