Part explained

Crankshaft position sensor: replacement, symptoms, diagnosis

A crankshaft position (CKP) sensor tells the engine management where the pistons are. If it fails, the engine doesn't know when to ignite or inject — and stalls. The notorious symptom: a warm engine stalls while driving and only starts again once it's cooled down. This page explains how to recognise it, what a new sensor costs and why diagnosis is worth more here than blind replacement.

By the onderdelen.autos editorial team · Updated 28 May 2026 · About the editorial team

What does the crankshaft sensor do?

The crankshaft sensor sits next to a toothed ring on the crankshaft (or flywheel) and delivers a pulse on every revolution. The engine management uses those pulses to determine the exact piston position — and so when the ignition coils should spark and the injectors should open. No signal: no ignition, no fuel, engine won't run. Sensors are usually inductive (two-wire) or Hall effect (three-wire); both fail mainly from heat (near the engine) or oil weeping into the connector.

Signs of a failed crankshaft sensor

Engine won't start — starter cranks but no ignition.
Car stalls while driving, often once warm; restarts after 15 – 30 minutes of cooling.
Check engine light on, fault code P0335 to P0339 ("crankshaft position sensor").
Rough idle or sudden power dips.
Tachometer jumps erratically or drops to zero while driving.
Long crank — engine fires only after 3 – 5 seconds of cranking.
Sometimes no fault code at all: the signal drops out too briefly for the system to log as a fault.

When to replace

Reactive, not preventive. Crankshaft sensors have no fixed interval; they fail between 100,000 and 250,000 km, or not at all. The classic pattern is a sensor that drops out when the engine is warm — a hot sensor has slightly higher resistance and can just miss the controller's threshold. **Diagnose first**: a P0335 fault code is a clue, not proof. The code can also come from a damaged reluctor ring, a dirty sensor seat or a bad ground point. With an oscilloscope you can measure the signal directly. Blind replacement fails to solve the issue in 20 – 30% of cases — and the sensor (unlike a spark plug or coil) is not always easy to reach.

What does a new crankshaft sensor cost?

Aftermarket: € 30 – € 80. OEM (Bosch, Continental, Delphi): € 60 – € 150. Used from a Dutch dismantler: € 10 – € 50 — a fine option, but given the awkward access (often behind the engine or under the intake) you don't want to be back at it within a year. Workshop cost: varies widely from 0.5 hour (easy access) to 3 hours (intake off, engine lifted). Ask specifically about access when getting a quote — the difference shapes the total bill.

Condition	From	To
New	€ 30	€ 150
Used / refurbished	€ 10	€ 50

Browse crankshaft sensors →

Compare inventory from Dutch sellers and order directly.

DIY or workshop?

Difficulty: Medium

The work itself is simple — one bolt and one connector — but access decides whether this is a 20-minute job or half a day. On some engines the sensor sits right next to the starter motor underneath; on others under the intake manifold. Watch a YouTube tutorial for your specific engine before you start. Important: disconnect the negative battery terminal first, fit the new sensor without bending the connector, and always clear the fault code afterwards.

Socket set with extension (sensor sits deep)
OBD-II reader to confirm the code and clear it after replacement
A flashlight and mirror — the sensor is rarely easy to see
Possibly a pit or lift for engines where the sensor is accessed from below

Frequently asked questions

My car stalls when warm and restarts after cooling — crankshaft sensor?

Classic symptom. But have it confirmed before you buy an expensive sensor: a workshop can scope the signal when the engine is warm. Other candidates are the mass air flow sensor, a clogged fuel filter or a failing ignition coil.

What's the difference with the camshaft sensor?

The crankshaft sensor measures crankshaft position (bottom), the camshaft sensor measures camshaft position (top). The crank is primary — without its signal the engine won't start. The camshaft sensor often falls back on the crank signal if it fails; the engine runs, just less efficiently and with a fault code.

Can I buy a used crankshaft sensor?

Yes, ideally with a short warranty (3 – 6 months from a Dutch seller). Given the awkward access, a used unit is a bit of a gamble — if it fails again in a year, the labour to replace is the same. For a car you plan to keep for years: new is often cheaper in the long run.

How do I know for sure it's the sensor and not the wiring?

Measure resistance between the two/three sensor pins (specs in the workshop manual). Out of tolerance: sensor. Within tolerance: wiring or controller. An experienced mechanic sees this in ten minutes on a scope; when in doubt you'll happily pay for that diagnosis.

Can I keep driving with a failing crankshaft sensor?

Until it stalls again — which is unpredictable. On a motorway that happens regularly and can be dangerous. Don't put it off, and if you do: stop taking long trips.