BMW 420i Gran Coupe F36 — Reliability

F36 Gran Coupe Mid 2014–2020 2 engines

Reliability Summary

Best engine B48 — 82/100 BUY
Worst engine N20 — 58/100 CAUTION
Average reliability 70/100

Engine Comparison

Engine Reliability Score Verdict Known Issues
B48
2.0L Turbo I4 		82/100 BUY Coolant vent line failure +2
N20
2.0L Turbo I4 		58/100 CAUTION Timing chain + guide + tensioner — class-action +2

Engines in this model

BUY 82

B48

2.0L Turbo I4

B58s little brother. Efficient, smooth. Remap to 260hp safe. Best modern 4-cyl BMW.

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CAUTION 58

N20

2.0L Turbo I4

Punchy turbo four. One known flaw (timing chain class-action 2012-15). After fix: 200k+ km.

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Known Issues Across All Engines

Issue Engine Severity Onset
Coolant vent line failure B48 moderate 40,000 km – 100,000 km
Oil filter housing gasket — early units (2014-2016) B48 moderate 40,000 km – 100,000 km
Intake valve carbon buildup (DI) B48 minor 60,000 km – 120,000 km
Timing chain + guide + tensioner — class-action N20 critical 60,000 km – 120,000 km
Electric water pump failure N20 high 80,000 km – 140,000 km
Oil filter housing gasket leak N20 moderate 60,000 km – 120,000 km

FAQ

Is the BMW 420i Gran Coupe reliable?

The BMW 420i Gran Coupe has 2 engine options with reliability scores ranging from 58/100 (CAUTION) to 82/100 (BUY). Average reliability: 70/100.

Which BMW 420i Gran Coupe engine is most reliable?

The B48 is the most reliable engine in the BMW 420i Gran Coupe, scoring 82/100 (BUY).

What problems does the BMW 420i Gran Coupe have?

Across all engine variants, the BMW 420i Gran Coupe has 6 known issues. The most common are related to Coolant vent line failure, Oil filter housing gasket — early units (2014-2016), Intake valve carbon buildup (DI).