The cooling system in a 2007 BMW 328i is crucial for maintaining optimal engine performance. Understanding the radiator hose diagram can help with maintenance and troubleshooting. Let's explore the key components and their locations.

Radiator Hose Layout

The radiator hose system in a 2007 BMW 328i consists of several main components:

  • Upper radiator hose: Connects the top of the radiator to the engine
  • Lower radiator hose: Links the bottom of the radiator to the engine
  • Expansion tank hose: Connects the expansion tank to the cooling system
  • Heater core hoses: Route coolant to and from the heater core

The upper and lower radiator hoses are the largest and most visible in the system.

Upper Radiator Hose

The upper radiator hose is a critical component in the cooling system. It carries hot coolant from the engine to the radiator for cooling. Key points about the upper hose:

  • Part number: 17127531579
  • Location: Connects from the top of the radiator to the engine block
  • Material: Typically made of reinforced rubber to withstand high temperatures and pressure

Replacing this hose may require removing the air box and charge pipe for better access.

Lower Radiator Hose

The lower radiator hose returns cooled fluid from the radiator back to the engine. Important details include:

  • Part number: 17127564478
  • Position: Runs from the bottom of the radiator to the engine's water pump
  • Access: May require lifting the vehicle and removing the splash guard for replacement

Heater Core Hoses

Heater core hoses are smaller in diameter and route coolant to the vehicle's heating system. The return line from the heater core to the thermostat has the following specifications:

  • Part number: 17127525870
  • Function: Carries coolant from the heater core back to the engine cooling system

Coolant Specifications

For the 2007 BMW 328i, use the following coolant specifications:

  • Type: BMW-approved coolant or equivalent phosphate-free antifreeze
  • Capacity: Approximately 8 liters (8.5 quarts) for the entire system
  • Mix ratio: 50/50 blend of coolant and distilled water

Always use the correct coolant to prevent corrosion and ensure proper heat transfer.

Maintenance Tips

To keep your BMW's cooling system in top condition:

  • Inspect hoses regularly for signs of wear, cracks, or leaks
  • Replace hoses at the first sign of deterioration
  • Use proper clamps when replacing hoses to ensure a tight seal
  • Bleed the system after any coolant service to remove air pockets
  • Check coolant level regularly and top up with the correct mixture

Proper maintenance of the radiator hoses and cooling system is essential for preventing overheating and ensuring the longevity of your BMW's engine.

FAQs About 2007 BMW 328i Radiator Hoses

    • How often should I replace the radiator hoses in my 2007 BMW 328i?
      It's recommended to inspect hoses annually and replace them every 4-5 years or at the first signs of wear, whichever comes first.
    • Can I use universal radiator hoses for my BMW?
      While universal hoses may fit, it's best to use OEM or exact-fit aftermarket hoses to ensure proper fitment and performance.
    • What are signs that my radiator hoses need replacement?
      Look for cracks, bulges, softness, or a spongy texture in the hoses. Coolant leaks or overheating can also indicate hose failure.