Is the N46B20 a good engine?
The BMW N46B20 is a reliable 4-cylinder petrol engine with good durability, but known for oil consumption issues in early models. This 2. L engine was used in several UK BMW models including the 1 Series (118i, 120i), 3 Series (318i, 320i) and 5 Series (520i) between 2004-2015. N63 V8 – The Oil-Guzzling Menace This twin-turbo V8 was supposed to bring effortless power to BMW’s luxury cars. Instead, it brought endless trips to the mechanic. Oil consumption was biblical, valve stem seals failed like clockwork, and the engine ran so hot it could fry an egg on the bonnet.The BMW N46 engine commonly suffers from oil leaks at the valve cover gasket and head gasket, plus excessive oil consumption due to ageing valve stem seals.
Is the N20B20 a good engine?
When properly maintained, the N20 can be a reliable engine—particularly post-2015 models which received revised timing chain components. However, reliability varies based on how well the car was serviced. Recommended Preventive Measures: Replace the timing chain and guides around 80,000–100,000 miles (on early models). Used BMW 1 Series reliability: the owners’ view The most significant concern involves the timing chain on early N47 diesel and N13 petrol engines, which can be costly to fix if a rattle is ignored. Other reported faults include electrical gremlins, such as failing ignition coils and drivetrain warning lights.The primary failure point in the bmw n20 engine is the plastic timing chain guides, which can degrade, crack, and break apart over time due to a material defect. Early warning signs include a high-pitched whining or whirring sound from the front of the engine, especially noticeable between 1,500-2,500 rpm.The N47 engine, used in BMWs from 2007 to 2014, is notorious for timing chain failures due to premature wear, often necessitating a complete engine breakdown as the chain is located at the rear of the engine.