BMW/N20
BMW · Single turbo

N20

328i·F30·2012–2015·1,997 cc

"In true BMW fashion, even the coffee mugs leak oil."

RISKY
42/ 100
"Timing chain ticking time bomb inside"
241
Max HP
350
Torque Nm
10,000
Oil interval km
4
Recalls
5
Known issues
Known Issues
Timing Chain & Guide Failure€2,500-6,000 · 60,000-130,000 kmCRITICAL

The N20 timing chain guide is prone to cracking and disintegrating, sending plastic debris into the oil system. Pre-2015 engines use an inferior guide design. Failures frequently occur just outside warranty. BMW issued a class action settlement (SI B11 02 21) covering a one-time diagnosis or repair benefit. Chain slack can be checked via endoscope through the oil cap.

Rattling or ticking on cold start
Chain slack visible via endoscope at oil cap
Drivetrain malfunction warning
Low oil pressure warning
Catastrophic engine seizure in severe cases
DIY: Expert
Electric Water Pump Failure€400-900 · 80,000-150,000 kmHIGH

The electric water pump is a known wear item on the N20. Failure leads to overheating, which can cause coolant loss, head gasket damage, and complete engine shutdown while driving. Multiple community reports confirm premature failure. Thermostat is typically replaced at the same time as a precaution.

Buzzing or humming noise from engine bay
Overheating warning on iDrive
Temperature gauge spike
Coolant loss or gurgling sounds
Vehicle losing power while driving
DIY: Moderate
Oil Filter Housing Gasket Coolant Leak€400-900 · 80,000-160,000 kmHIGH

The oil filter housing gasket is a well-documented failure point on the N20, causing coolant to leak into the engine bay or mix with oil. A class action was initiated in Canada regarding this issue. Neglecting the repair risks coolant contamination of engine oil and accelerated engine wear.

Visible coolant leak at front of engine
Milky oil on dipstick
Sweet smell from engine bay
Coolant level dropping without visible external leak
DIY: Moderate
Turbo Coolant Line Leaks€200-600 · 80,000-160,000 kmMODERATE

Coolant supply and drain lines to the turbocharger are known to fail on the N20, causing coolant loss and potential overheating. Replacement with OEM lines and a full cooling system bleed procedure is required.

Coolant leak at rear of engine near turbo
Coolant level dropping
Overheating warning
Visible coolant residue around turbo area
DIY: Moderate
Intermittent Low Oil Pressure Warning€150-500 · 50,000-120,000 kmMODERATE

Multiple N20 owners report intermittent low oil pressure warnings that disappear after restarting. This may be related to oil pressure sensor faults, oil pump chain wear, or early timing chain guide debris contaminating the oil pick-up. Should not be ignored as it may indicate a developing timing chain problem.

Low oil pressure warning on iDrive
Warning clears after engine restart
No obvious oil level loss
Occasional drivetrain malfunction message
DIY: Low
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Buying Checklist
Perform an endoscope inspection through the oil cap to check for timing chain guide cracks, plastic debris, and chain slack before purchasing
Scan with ISTA or Carly for fault codes related to timing, oil pressure, water pump, and cooling system — do not accept a generic OBD2 scan
Check full service history for evidence of water pump and thermostat replacement; treat absence of this as a near-term expense
Inspect the oil filter housing area and coolant reservoir for signs of coolant leaks or milky oil contamination
Verify all open recalls have been completed by the dealer, especially the brake vacuum and airbag recalls
Cold-start the engine and listen for timing chain rattle or ticking in the first 30 seconds — any rattling is a serious red flag
Service Reality
Community oil interval10,000 km
Oil specificationBMW Longlife-01, 5W-30 full synthetic (e.g. Castrol Edge 5W-30 LL)
Est. ownership cost (2yr)€1,500–3,500 in the first year of ownership if timing chain, water pump, and gasket work has not been done; ongoing maintenance €800–1,500/year thereafter
Real fuel consumptionNo data
Also Found In
BMW 320i F30BMW 520i F10BMW 528i F10BMW X1 xDrive20i E84BMW X3 xDrive20i F25BMW Z4 sDrive20i E89
Buying Advice

The BMW N20 in the F30 328i is a genuinely capable engine let down by a well-documented and potentially catastrophic timing chain guide failure that affects primarily pre-2015 cars. Before buying, insist on an endoscope inspection of the timing chain — if the guide shows cracks or there is visible debris in the oil, walk away or negotiate a significant price reduction to cover a full timing chain job. Budget €1,500–2,500 immediately after purchase for water pump, thermostat, and oil filter housing gasket replacement if not already done. This car rewards buyers who do their homework and maintain it aggressively, but it will punish neglect with bills that can exceed the car's value.

Parts People Buy
N20 Timing Chain Kit (Chain, Guide, Tensioner)Link unavailable
N20 Electric Water Pump & Thermostat KitLink unavailable
N20 Oil Filter Housing GasketLink unavailable
N20 Turbo Coolant Supply & Return LinesLink unavailable
BMW N20 Oil Pressure SensorLink unavailable
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