What is the reason for the water pipe rupture in BMW 320?

[RiverRose]

The reason for the water pipe rupture in BMW 320 is: thermostat failure. Introduction to car thermostat: The thermostat is a valve that controls the flow path of the coolant. It is an automatic temperature-regulating device, usually containing a temperature-sensing component, which opens or closes the flow of air, gas, or liquid by means of thermal expansion or contraction. Working principle of the thermostat: The thermostat automatically adjusts the amount of water entering the radiator based on the temperature of the cooling water, changes the circulation range of the water, and regulates the cooling capacity of the cooling system to ensure the engine operates within a suitable temperature range. The thermostat must maintain good technical condition, otherwise it will seriously affect the normal operation of the engine.

[LaJayce]

I've been repairing BMWs for over a decade and have seen plenty of coolant hose failures. The main issue is that small rubber hose in the engine bay can't withstand long-term stress - the material becomes brittle with heat aging and naturally cracks over time. Using counterfeit or expired coolant can cause acidic corrosion that eats through hoses from the inside. Aggressive drivers who frequently overheat their engines create excessive cooling system pressure that can burst hoses. Poor assembly work like loose hose clamps or accidental scratches during part replacement also lead to later leaks. I recommend inspecting hoses annually, especially on vehicles over five years old, as rubber degradation is inevitable - replacing them preemptively saves headaches.

[StChloe]

This issue is particularly common in used BMWs, especially in 320 models over eight years old. The main reason for hose ruptures is aging, as rubber components gradually harden and crack under high temperatures. Some cars that haven't used genuine coolant for long periods accumulate scale in the radiator, blocking the pipes and causing them to burst under pressure at weak points. Another easily overlooked cause: frequent driving on rough roads can lead to flying stones hitting the hoses underneath. The damage might not be visible externally but can weaken the hose internally. I once bought a car like this where the owner thought it was a quality issue, but it was actually caused by road abrasion. For prevention, try to avoid parking over deep potholes or gravel roads, and regular radiator cleaning can also help.

[VonLouis]

My 10-year-old BMW 320 once experienced a hose rupture, and it wasn't until it was towed to the repair shop that the problem was discovered. The mechanic said the main reason was that the coolant hadn't been changed for six years, and the additives inside had failed, corroding the pipe walls. Another time, while washing the car, I noticed coolant leaking all over the ground. Upon inspection, it turned out that the engine compartment had been running at excessively high temperatures for a long time, causing the plastic connectors to warp. Now I've learned my lesson and check the hoses' flexibility every year before summer, replacing any that feel hard when squeezed in advance. The repair technician shared a handy tip: before starting the car, check the ground beneath for any pink water stains—if there are any, there's an 80% chance it's a hose leak. I'd advise fellow long-time BMW owners to pay special attention to this, as a single repair can cost over two thousand yuan.