The B48 replaced the N20 as BMW's 2.0 turbo petrol. It is in the 320i, 330i, 520i, X3 20i, Mini Cooper S of the later years, and a lot of other cars. Because it is common, listings are careless. "2.0 turbo petrol" is not an order.
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B48B20A, B48B20B and the later tunes are different maps and sometimes different hardware. A 320i engine and a Cooper S engine can share the family and still be the wrong computer, the wrong turbo and the wrong sump for each other's cars. The stamp is on the block. We photograph it.
Pump, coolant and carbon
The high-pressure fuel pump sits on the end of the head and is a known leak and failure point. Look for fuel staining around it. The coolant flange and the oil filter housing area should be dry. Some white residue on an old hose is history. A wet joint is a job you will do at fitting, so it belongs in the price conversation.
Every direct-injection B48 has carbon on the intake valves. That is how these engines run. It is not a reason to reject a unit, and a seller who claims the valves are bare is guessing unless the intake is off.
The pan and the car
xDrive cars and some Minis use a different oil pan and pickup. Take the pan from the correct engine, not from the broken one, unless your workshop has compared them. Send the VIN and we will say whether the unit in stock is the right pan before you pay.
Full B48 guide · B48B20A from an X2
While it is out
Replace the coolant flange if it is the plastic one that goes brittle, and replace the oil-filter housing gasket. Both are easier with the engine on the hoist than after it is in the car. The high-pressure pump that stained the head should be replaced now, not cleaned and hoped over.
The first start should be a long idle, then a check for fuel at the pump and coolant at the flange, before anyone drives it.
The yard is at Andreas Meyer Straße 38, 22113 Hamburg. Call or WhatsApp +49 15510 030835, or email autowerkeengines@gmail.com, Monday to Friday, 9:00 to 16:00 CET. Shipping is 249 € per order. We are an independent seller, not BMW AG.