325i / 330i 3.0 (N52)
2005–2011 · petrol · 2996cc · 272hp
Engine codes: N52
Reliability, common problems and owner reviews for the Bmw 3 Series E90 325i / 330i 3.0 (N52). Check this before you buy used.
The N52 straight-six petrol is smooth and fundamentally durable, but it's badly outgunned by the X5's two-tonne-plus bulk — genuinely thirsty for the performance you get. Chain-driven and robust mechanically; the age items are the electric water pump and thermostat (plan to replace), valve-cover and oil-filter-housing gaskets, and VANOS. No design disasters, but most X5 buyers want a diesel — the petrol only suits low-mileage, fuel-cost-tolerant use.
Same engine, other cars
This is the same physical engine (N52) sold under different names across brands. Reliability is broadly shared — cross-check these:
Known Issues
Electric water pump fails with age.
Fix / Workaround: Replace proactively (pump + thermostat).
Repair cost: €300–€700
Typically appears after: 130,000 km
Valve cover / oil filter housing gaskets leak.
Fix / Workaround: Replace gaskets.
Repair cost: €150–€600
The N52's electric water pump is a known service item — it fails without much warning between roughly 120,000 and 180,000 km, usually together with the electronically-controlled thermostat. Failure means overheating within minutes, and the magnesium-aluminium block does not forgive overheating.
Fix / Workaround: Replace pump + thermostat proactively around 150,000 km or at the first slow-warm-up / overheat warning. Not a cheap part, but far cheaper than a cooked engine.
Repair cost: €450–€900
Typically appears after: 120,000 km
Two classic N52 age items: the Valvetronic eccentric shaft sensor fails (rough running, limp mode), and the valve cover + oil filter housing gaskets harden and leak oil — sometimes onto the belt and alternator below. Lifter tick on cold start at high mileage is also common and mostly benign.
Fix / Workaround: Budget for valve cover and oil filter housing gaskets on any 150k+ example; eccentric shaft sensor is a valve-cover-off job — do them together.
Repair cost: €300–€800
Typically appears after: 140,000 km
N52 electric water pump and thermostat fail with age → overheating risk.
Fix / Workaround: Replace pump + thermostat proactively.
Repair cost: €350–€800
Typically appears after: 130,000 km
Valve-cover and oil-filter-housing gaskets weep oil.
Fix / Workaround: Replace gaskets.
Repair cost: €150–€600
Typically appears after: 140,000 km
Mileage Thresholds
After 250,000 km: Long-lived with upkeep.
After 150,000 km: Do the electric water pump + thermostat proactively here if there's no record of them being changed — the single most important N52 preventive job.
After 200,000 km: Durable; cooling is the watch item.
Fault Codes to Scan
Pre-Purchase Checklist
- ☐Water pump history
- ☐Oil-leak inspection
- ☐Excellent choice
- ☐Water pump + thermostat history
- ☐Gasket leak check
- ☐Thirsty — diesel is the sensible X5
Frequently asked questions
Is the Bmw 3 Series E90 325i / 330i 3.0 (N52) reliable?
Maint. Sensitive — The N52 straight-six petrol is smooth and fundamentally durable, but it's badly outgunned by the X5's two-tonne-plus bulk — genuinely thirsty for the performance you get. Chain-driven and robust mechanically; the age items are the electric water pump and thermostat (plan to replace), valve-cover and oil-filter-housing gaskets, and VANOS. No design disasters, but most X5 buyers want a diesel — the petrol only suits low-mileage, fuel-cost-tolerant use.
What are the common problems and reviews for the Bmw 3 Series E90 325i / 330i 3.0 (N52)?
The most commonly reported problems: Electric water pump failure, Oil leaks (gaskets), Electric water pump and thermostat failure, Valvetronic eccentric shaft sensor and oil leaks, Electric water pump / thermostat, Gasket leaks (VCG / OFHG).
Is a used Bmw 3 Series E90 325i / 330i 3.0 (N52) worth buying?
Fine if serviced correctly — but it punishes neglect hard. History and the right consumables matter.