Car Model Guide/ Issues/ Eccentric shaft sensor leak

Eccentric shaft sensor leak

Attaches to N52 at engine level · Electrical · carried by 18 variants across 8 chassis

Overview

Eccentric shaft sensor leak is a occasional fault recorded against N52 at engine level, typically from 100–200k km. It shows up as oil seeping from the Valvetronic sensor on the side of the head; in the worst case oil tracks into the wiring. Where it's documented, the repair runs €250–€450 (sensor and seal at an independent, costs dated 2026-07), and it can be checked before you buy. 18 variants across 8 chassis in this database inherit it.

€250 – €450
sensor and seal at an independent · costs dated
Likelihoodoccasional
Typical onset100–200k km
Detectableyes
Walk awayno
Evidencedocumented

What happens

Symptom. Oil seeping from the Valvetronic sensor on the side of the head; in the worst case oil tracks into the wiring.

Cause. The sensor's seal hardens.

How to check it

Static checks

Look at the intake side of the head for a wet sensor body and oil tracking down the loom.

Engine off, ideally on a lift.

ElectricaloccasionalDetectable at viewingevidence: documented100200k km

Every variant that carries this

VariantChassisBodyYearsRiskGood buyCost as % of good buy
323i N52E90sedan2005–2007R2€4,0509%
323i N52E91wagon2005–2007R2€4,3008%
323i N52E92coupe2006–2007R2€4,6508%
325i N52E90sedan2005–2007R2€4,7507%
325i N52E91wagon2005–2007R2€5,0507%
325i N52E92coupe2006–2007R2€5,4506%
325i N52E93convertible2007R2€5,3507%
328i N52E90sedan2006–2011R2€5,1507%
328i N52E91wagon2006–2012R2€5,4506%
328i N52E92coupe2006–2013R2€5,9506%
328i N52E93convertible2007–2013R2€5,7506%
330i N52E90sedan2005–2007R2€5,6006%
330i N52E91wagon2005–2007R2€5,9506%
330i N52E92coupe2006–2007R2€6,4505%
125i N52E82coupe2008–2013R2€7,0005%
125i N52E88convertible2008–2013R2€7,4005%
130i N52E87hatchback2005–2011R2€7,0005%
130i N52E81hatchback2007–2011R2€6,8005%

The last column is the point. The same repair is an inconvenience on one variant and a reason to scrap the car on another. A failure costing a quarter of the vehicle's value changes the purchase decision regardless of how rare it is.