The problem
This BMW came to us with the B48 2.0 litre petrol engine. The customer could smell coolant after driving, and the coolant level kept dropping.
When we checked under the car, we found coolant leaking from the water pump and the water pump bracket.
What does the water pump do?
The water pump moves coolant around the engine. This keeps the engine at the right temperature. If the pump leaks, the coolant level drops and the engine can overheat.
On the B48, the water pump sits at the front of the engine with a bracket that connects it to the engine block.
What went wrong
Over time, the seals and gaskets on the pump and bracket get old and stop sealing. Coolant slowly leaks out.
When the leaked coolant dries, it leaves a crusty white, green or yellow mess on the engine. In this car, we found heavy coolant crust around the pump, the bracket and the pipes. Some of the leak had also mixed with dirt and oil around the area.
Warning signs
- Sweet coolant smell after driving
- Low coolant warning on the dash
- You need to top up coolant often
- White, green or yellow crust on the engine
- Steam from the engine bay
- Engine temperature higher than normal
Which BMWs have the B48 engine?
The B48 is found in many modern BMWs, including the 320i, 330i, 220i, 230i, 520i, 530i, X1, X3 and some MINI Cooper S models.
What we did
- Pressure tested the cooling system to find the leak
- Removed the water pump and bracket
- Cleaned the engine sealing surfaces and removed old coolant crust
- Fitted a new water pump with new seals and gaskets
- Refilled with the correct BMW coolant
- Bled the air from the cooling system
- Pressure tested again and road tested the car
The result
No more leaks, no more coolant smell, and the engine temperature is stable.
Don’t ignore a coolant leak
A small leak can become a big problem. If the coolant gets too low, the engine can overheat. Overheating can damage the cylinder head, the head gasket and other parts. Fixing the leak early costs much less.
Prevention tips
- Check your coolant level regularly
- Only use BMW-approved coolant
- If you smell coolant, get it checked quickly
- Look for crusty marks around the front of the engine
How we can help
At WA Auto Service Center in Bibra Lake, we specialise in BMW. If your BMW smells of coolant or keeps losing coolant, book an inspection with us today.
