BMW 5 Series: Valvetronic Motor & Eccentric Shaft Sensor Failure
Valvetronic Motor & Eccentric Shaft Sensor Failure is a common engine fault on the BMW 5 Series on the 2003–2010 cars, and we rate it major. Putting it right costs $900 to $2,800 at New Zealand independent workshop rates. Below is what goes wrong, the symptoms to notice on a test drive, where to look, and what to ask the seller before you hand over any money. It is one of 58 documented faults on the BMW 5 Series.
- Vehicle
- BMW 5 Series
- Years
- 2003–2010
- Fuel
- petrol
- System
- Engine
What you are looking at
No photograph available
What goes wrong
BMW's Valvetronic system replaces the conventional throttle plate by continuously varying intake valve lift via an eccentric shaft driven by an electric motor. The eccentric shaft position sensor monitors shaft angle in real time; if the sensor or motor signal is lost, the DME cannot guarantee safe valve lift and immediately triggers limp mode, capping the engine at approximately 3000 RPM. On N52 and N53 engines in E60/E61 models, the sensor and its wiring connector suffer corrosion from condensation and heat cycling in the valve cover area. The Valvetronic motor itself develops brush and commutator wear at higher mileages. Failure can also be caused by a seized or carbon-fouled eccentric shaft preventing the motor from turning the shaft to the commanded position.
What you would notice
- Engine enters limp mode with RPM hard-limited to 3000
- Engine warning light illuminated
- Rough idle and jerky throttle response
- Fault codes referencing Valvetronic motor or eccentric shaft sensor
- Sudden power loss while driving
How to check it
Where to look. Top of engine, intake side valve cover — eccentric shaft runs across the front of the cylinder head
Inspect the eccentric shaft sensor wiring harness and connector at the front of the valve cover for corrosion or chafing. Attempt to command Valvetronic motor movement via live data and confirm shaft position feedback. Check valve cover area for oil leaks that can contaminate connectors. If a workshop inspection is possible: Use a BMW-capable OBD scanner to check for Valvetronic-specific fault codes.
What it costs to put right
$900 to $2,800 at New Zealand independent workshop rates. That is for this job on its own, not for the car.
Ask the seller
- “Has the engine ever entered limp mode or been RPM-limited?”
- “Has the Valvetronic motor or eccentric shaft sensor been replaced?”
- “Are there any stored engine fault codes currently?”
- “Has the valve cover gasket been replaced to prevent oil contaminating the sensor connector?”
Now check the BMW 5 Series you are actually looking at
Everything above is true of the model, and it is free. What it does not tell you is whether THIS car has been looked after: its odometer history and whether the reading has ever gone backwards, whether there is still money owing on it, whether it has been reported stolen, how many owners it has had and what it is really worth today. That comes from the official records for that plate. Enter the plate for the free details, or get the full history and a market valuation from $13.49.
Where this comes from
BMW 5 Series buyer questions
Is valvetronic motor & eccentric shaft sensor failure serious on a BMW 5 Series?
We rate it major and common on the BMW 5 Series. BMW's Valvetronic system replaces the conventional throttle plate by continuously varying intake valve lift via an eccentric shaft driven by an electric motor. The eccentric shaft position sensor monitors shaft angle in real time; if the sensor or motor signal is lost, the DME cannot guarantee safe valve lift and immediately triggers limp mode, capping the engine at approximately 3000 RPM. On N52 and N53 engines in E60/E61 models, the sensor and its wiring connector suffer corrosion from condensation and heat cycling in the valve cover area. The Valvetronic motor itself develops brush and commutator wear at higher mileages. Failure can also be caused by a seized or carbon-fouled eccentric shaft preventing the motor from turning the shaft to the commanded position.
How much does it cost to fix on a BMW 5 Series?
$900 to $2,800 at New Zealand independent workshop rates. That figure is for this job on its own. A car showing the symptoms on this page is usually worth either walking away from or negotiating down by at least the repair figure.
Which BMW 5 Series years are affected?
Our research records this fault on the 2003–2010 BMW 5 Series. Build dates move around, especially on imported cars, so treat the range as the years to look hardest at rather than a guarantee either way. The official records tell you the exact build and first registration date for the car in front of you.
How do I check for it before I buy?
Inspect the eccentric shaft sensor wiring harness and connector at the front of the valve cover for corrosion or chafing. Attempt to command Valvetronic motor movement via live data and confirm shaft position feedback. Check valve cover area for oil leaks that can contaminate connectors. If a workshop inspection is possible: Use a BMW-capable OBD scanner to check for Valvetronic-specific fault codes. Look here: Top of engine, intake side valve cover — eccentric shaft runs across the front of the cylinder head