BMW N52 engine report
BMW N52 · 328i (E90)
3.0 LPetrolInline-62006–2012
74/100
[good]
A tough straight-six, once the recalls and cooling are sorted
Worth buying, but only on the right car. Proof that the NHTSA recalls for the VANOS bolts and the PCV heater have been carried out, and records showing the electric water pump, thermostat and oil filter housing gasket have been replaced.
ExcellentGoodSolidRiskyAvoid
- Known issues
- 16
- Critical
- 5
- Sources
- 113
Verdict
Worth buying, with money set aside for the age-related jobs.
Oil leaks from seals and gaskets, the water pump, the thermostat and the VANOS solenoids are the common ones, so check for all of them before you buy. On cars built from 2009 to 2011, make sure the VANOS bolt recall has been done, because a sheared bolt can wreck the engine. Oil consumption and oil pump wear are less frequent but more serious, which is why the service history matters. Head gasket and ringland failures are rare, and a car showing any sign of them is one to walk away from.
Specs
- Displacement
- 3.0 L
- Layout
- Inline-6
- Fuel
- Petrol
- Production
- 2004–2015
- Chassis
- E90
- Generation
- E90 NA
- Fitted
- 2006–2012
Known issues
16 confirmed · sorted by severity
CriticalVANOS bolt failure
The bolts that hold the VANOS unit to the cylinder head can work loose or snap. The engine then runs rough, loses power and may not restart, and broken bolts left in place can do serious damage. BMW recalled affected cars to fit revised bolts, so check that the recall work has been done.
Symptoms
- Warning Light
- Reduced Power Mode
- Rough Idle
- Knocking Noise
How often
Occasional · Manufacturing defect. Can destroy the engine if ignored. Not safely drivable.
Evidence
1 owner report backs this, confidence 95/100.
CriticalCrankcase vent heater short
A small heater keeps the crankcase ventilation line from freezing. Its element or connector can short and overheat, and at worst start a fire in the engine bay. BMW recalled affected cars for a redesigned heater and wiring, so check that the recall work has been done.
Symptoms
- Smoke (White/Blue/Black)
- Warning Light
How often
Rare · Manufacturing defect. Can destroy the engine if ignored. Not safely drivable.
Evidence
1 owner report backs this, confidence 95/100.
CriticalHead gasket failure
Head gasket failure, often preceded by overheating; can lead to a warped head or cracked block if not addressed.
Symptoms
- Coolant Loss
- Smoke (White/Blue/Black)
- Warning Light
How often
Rare · Design weakness. Does not normally destroy the engine. Not safely drivable.
Evidence
9 owner reports back this, confidence 50/100.
CriticalOil pump wear / sludge buildup
Oil pump wear or sludge accumulation (often from extended oil-change intervals) reducing oil pressure and lubrication.
Symptoms
- Warning Light
- Knocking Noise
How often
Rare · Design weakness. Does not normally destroy the engine. Not safely drivable.
Evidence
10 owner reports back this, confidence 45/100.
CriticalPiston ringland failure
Piston ringland cracking under high cylinder pressure/heat, common on tuned forced-induction engines.
Symptoms
- Power Loss
- Smoke (White/Blue/Black)
- Misfire
How often
Very rare · Design weakness. Can destroy the engine if ignored. Not safely drivable.
Evidence
2 owner reports back this, confidence 45/100.
HighHigh-pressure fuel pump failure
HPFP wear or failure, sometimes shedding metal debris into the fuel system.
Symptoms
- Misfire
- Warning Light
- Hesitation
How often
Rare · Age-related wear. Does not normally destroy the engine. Not safely drivable.
Evidence
6 owner reports back this, confidence 50/100.
ModerateWater pump failure
Water pump seal or bearing failure (mechanical or electric pump), causing coolant loss.
Symptoms
- Coolant Loss
- Warning Light
How often
Common · Design weakness. Does not normally destroy the engine. Still drivable.
Evidence
23 owner reports back this, confidence 50/100.
ModerateExcessive oil consumption
Worn valve stem seals, piston rings, or a clogged PCV/oil separator system causing oil consumption above manufacturer spec.
Symptoms
- Oil Consumption
- Smoke (White/Blue/Black)
How often
Rare · Design weakness. Does not normally destroy the engine. Still drivable.
Evidence
7 owner reports back this, confidence 60/100.
ModerateHead bolt stretch
Head bolts stretch beyond spec (often single-use bolts reused incorrectly during service), risking head gasket failure.
Symptoms
- Coolant Loss
- Warning Light
How often
Rare · Design weakness. Does not normally destroy the engine. Still drivable.
Evidence
5 owner reports back this, confidence 45/100.
ModerateDual-mass flywheel / clutch wear
Dual-mass flywheel wear causing rattle/vibration, often coinciding with clutch replacement interval.
Symptoms
- Excessive Vibration
- Knocking Noise
How often
Very rare · Expected maintenance. Does not normally destroy the engine. Still drivable.
Evidence
3 owner reports back this, confidence 40/100.
LowVariable valve timing solenoid/actuator failure
VANOS/VTEC/VVT-style variable valve timing solenoids or actuators fail or clog, causing rough idle, rattle on start, or reduced power.
Symptoms
- Rough Idle
- Reduced Power Mode
- Warning Light
How often
Very common · Design weakness. Does not normally destroy the engine. Still drivable.
Evidence
59 owner reports back this, confidence 55/100.
LowOil leak from seals or gaskets
Valve cover gasket, rear main seal, or front main seal degradation causing external oil leaks.
Symptoms
- Oil Consumption
How often
Common · Design weakness. Does not normally destroy the engine. Still drivable.
Evidence
38 owner reports back this, confidence 65/100.
LowThermostat / temperature sensor failure
Thermostat sticking open or closed, or temperature sensor drift, causing incorrect operating temperature.
Symptoms
- Warning Light
How often
Common · Age-related wear. Does not normally destroy the engine. Still drivable.
Evidence
31 owner reports back this, confidence 50/100.
LowEngine sensor failure
Crankshaft, camshaft, MAP, lambda/O2, or MAF sensor failure causing rough running, stalling, or incorrect fueling.
Symptoms
- Warning Light
- Rough Idle
- Misfire
How often
Occasional · Age-related wear. Does not normally destroy the engine. Still drivable.
Evidence
12 owner reports back this, confidence 50/100.
LowFuel injector failure
Injector wear, sticking, or seal failure causing misfires, rough running, or fuel leaks.
Symptoms
- Misfire
- Rough Idle
- Fuel Smell
How often
Very rare · Age-related wear. Does not normally destroy the engine. Still drivable.
Evidence
4 owner reports back this, confidence 45/100.
LowECU fault or wiring issue
ECU hardware fault or injector wiring loom degradation causing misfires or no-start conditions.
Symptoms
- Warning Light
- Misfire
How often
Very rare · Manufacturing defect. Does not normally destroy the engine. Still drivable.
Evidence
2 owner reports back this, confidence 45/100.
- Critical
- High
- Moderate
- Low
VANOS bolt failurefrom 110k km
Crankcase vent heater shortfrom 120k km
Head gasket failurefrom 95k km
Water pump failurefrom 232k km
Oil pump wear / sludge buildupfrom 116k km
High-pressure fuel pump failurefrom 97k km
Variable valve timing solenoid/actuator failurefrom 135k km
Oil leak from seals or gasketsfrom 209k km
Showing the 8 highest-impact of 16 dated issues. The rest are in the list above.
Buying checklist
0 of 14 checked
Sources
Updated 15 Sept 2026 · scoring v2.7
Behind this report sit 113 owner posts, forum threads and official records. Nothing gets on the list on one person's word. It takes a recall, or owners on separate platforms describing the same fault. The score then sets how often a problem turns up against the damage it does.