BMW 3 Series common faults, MOT red flags & buyer's guide
F30 (2012–2018) & G20 (2019–) · Saloon / Touring
Brilliant to drive — but running costs bite if you don't buy carefully.
BMW 3 Series common faults
Each fault below is drawn from real owner reports and UK garage patterns for this generation — not generic used-car advice.
N47 diesel timing chain (pre-2016)
criticalN47 2.0d timing chain sits at the back of the engine — failure means engine-out repair costing thousands.
Check for: Diesel rattle on start-up. Ask specifically if chain has been done.
Typical cost: £1,800–£3,000
EGR cooler leak (recall)
seriousEGR cooler recall affected many diesel BMWs — check the recall is done or fire risk remains.
Check for: gov.uk/check-vehicle-recall by reg.
Typical cost: Free under recall; £500+ otherwise
Water pump (electric)
moderateElectric water pumps fail around 60–90k miles.
Check for: Overheat warnings, coolant loss.
Typical cost: £450–£700
MOT history red flags
If any of these appear on the last two MOTs, negotiate hard or walk away.
- Emissions failure on diesel
- Any 'suspension bush' advisory — front control arm bushes are consumables
Sharp questions to ask the seller
- N47 diesel: has the timing chain been replaced?
- EGR recall done?
- Full BMW or independent BMW specialist history?
Got a specific BMW 3 Series in mind?
Paste the reg and we'll pull its full MOT history, cross-check against these faults, and tell you: buy, negotiate or walk away.