Blog Description
BMW B48 engines are commonly found in models such as the 118i,120i, 220i, 320i, 330i, 420i, 430i, X1, X2, X3 and other modern BMWs. One common issue we see is coolant leaking from the oil filter housing area or the coolant flange.

The oil filter housing on the B48 engine carries both oil and coolant passages. Over time, the housing or seals can crack, leak or fail, causing coolant loss. The coolant flange and connected hoses can also become brittle from heat and age, leading to slow leaks or sudden coolant loss.

Common signs include low coolant warning, visible coolant residue, overheating, coolant smell, or coolant leaking around the front/side of the engine. If ignored, coolant leaks can lead to overheating and possible engine damage.

At WA Auto Service Center, we inspect the full cooling system, pressure test the system, check for leaks around the oil filter housing, coolant flange, hoses and related components, then provide a clear repair quote before carrying out the work.