What this guide covers
This guide covers the 2018 and later G01 X3 with the B46 and B48 four-cylinders and the B58 in the M40i, according to our repair pages. The chassis page is BMW G01 repair costs. These are owner-reported repairs, not failure rates.
Cooling system
On the xDrive30i, look for a coolant leak at the front of the engine (Water Pump (N20 / B46 / B48)) and for crusty residue around the turbo lines (B46/B48 Turbo Coolant Return Line). On the M40i, the plastic oil filter housing and the water pump are the cooling items (B58 / B48 Oil Filter Housing (Coolant Leak), B58 Water Pump (Coolant Pump)). Engine guides: BMW B46 and B48 Common Problems and Repair Costs and BMW B58 Common Problems and Repair Costs.
Oil and the rear end
The B58 valve cover is replaced as an assembly with long labor (B58 Valve Cover Replacement). Rear differential axle seals usually show as a seep found on a lift; a forum member says about two hundred dollars of one-time-use bolts must be replaced for the job (G01 X3 Rear Differential Axle Seals). Oil service on four-cylinder cars may qualify for BMW Value Service pricing (Oil Change / Oil Service).
xDrive fluids and wheels
Budget for the transfer case and differential fluids (Transfer Case Fluid (xDrive), Front Differential Fluid (xDrive)), coolant (Coolant Flush / Coolant Service) and brake fluid (Brake Fluid Flush / Service). TPMS sensor batteries wear out with age (TPMS Tire Pressure Sensors (Set of 4)), and an alignment is needed after suspension work (Wheel Alignment).
Small repairs
Hood lift struts use BMW part 51237397493 on both sides and are an easy DIY (Hood Lift Struts (G01 X3)). Plugs are the scheduled item on the engine (Spark Plugs & Ignition Coils (B58 / B48)). Older X3 buyers see BMW X3 F25 Buying Guide: What It Costs to Fix.