1. B48 Cooling System Leaks(Water Pump, Thermostat, Coolant Hoses)
Symptoms: Low coolant warning, coolant loss with no visible external leak, sweet smell from engine bay, temperature fluctuations, overheating.
Typical Mileage: 40,000–80,000 miles
Repair Cost: £400–£1,200 (water pump, thermostat, or coolant hose replacement)【PLACEHOLDER】
Replacement Cost: N/A — repair only (unless overheating leads to engine damage)
Urgency: Check — book inspection urgently if coolant loss is detected
Our recommendation:
The B48 engine has a well-documented cooling system weakness. Coolant leaks from the water pump, thermostat housing, and coolant hoses are common, with most issues appearing between 40,000 and 80,000 miles. The electric water pump often fails after 80,000 km and the thermostat housing can crack. If you notice coolant loss or temperature fluctuations, have the system pressure-tested immediately. Proactive replacement of known weak coolant hoses at 60,000 miles is recommended.








