Porsche Boxster Crankshaft Position Sensor Guide (2004-2008)
Everything you need to know about a failing crankshaft position sensor in your 986 or 987 Boxster.
- A common failure symptom is the engine stalling when hot and not restarting until it cools down.
- This is a critical failure; do not drive the car if you suspect the sensor is bad, as it can stall at any time.
- Bosch is the OEM supplier; using a Bosch aftermarket sensor is the most recommended and reliable repair choice.
- The job can be done by a DIY mechanic, but access is tight and requires removing the rear passenger wheel.
Understanding Crankshaft Position Sensor Failure in the 2004-2008 Boxster
A failing crankshaft position sensor is a known issue that can leave a Porsche Boxster owner stranded. The symptoms often appear when the engine gets hot, leading to a frustrating situation where the car runs fine for a while, then suddenly stalls and refuses to restart until it has cooled down. This happens because the sensor's internal electronics can fail under heat, cutting off the vital signal to the engine computer. When the computer loses this signal, it shuts down the fuel and ignition systems as a precaution, effectively killing the engine.
🎬 Watch: One owner's experience diagnosing and fixing this stalling issue.Critical Failure Warning
A bad crankshaft position sensor can cause your engine to stall suddenly while driving. This is a serious safety risk, especially in traffic or at high speeds. If you suspect your sensor is failing, it is not recommended to drive the vehicle until it has been repaired.
Choosing the Right Aftermarket Sensor
When replacing this sensor, you have a choice between the original Porsche part and several aftermarket brands. For many German vehicles, including Porsche, the original parts are often made by a well-known supplier. In this case, Bosch is the Original Equipment Manufacturer (OEM) for the Boxster's crankshaft position sensor.
- Top Tier (OEM Supplier): Bosch is widely considered the best choice. Since they make the original part for Porsche, their aftermarket sensor is identical in quality and function but usually costs significantly less than the Porsche-branded equivalent. Most Porsche specialists and experienced owners recommend using only Bosch for critical electronic sensors to avoid future problems.
- Mid/Economy Tier (Spectra, Standard Ignition, Walker Products): While other brands are available and may be cheaper, they are generally not recommended for this specific, critical part on a Porsche. Forum discussions among long-time owners often warn against using non-Bosch electronic parts, citing potential for premature failure and creating more diagnostic work down the road. Given the labor involved and the critical function of this sensor, saving a few dollars on a lesser-known brand is a risk that may not be worth taking.
Pro Tip: Check the Connector
Before ordering, it's wise to visually inspect the existing sensor's electrical connector if possible. While parts for the 2004-2008 range are generally consistent, slight variations can exist. Also, check for loose or damaged wiring, as this can sometimes mimic the symptoms of a failed sensor.
Cost of Replacement (2004-2008 Porsche Boxster)
| Part / Service | Estimated Cost |
|---|---|
| New OEM (Porsche Branded) | $270 - $340 |
| New Aftermarket (Bosch OEM Supplier) | $85 - $100 |
| New Aftermarket (Other Brands) | $85 - $178 |
| Shop Labor | $150 - $250 |
| Total Professional Replacement | $401 - $542 |
Frequently Asked Questions
Is this a difficult DIY job?
It is considered a moderately difficult job, mainly due to tight access. The sensor is located on the passenger side of the engine near the transmission, and you typically need to remove the rear wheel to get to it. It is held by a single 5mm Allen or T30 Torx bolt. The main challenges are seeing the sensor, reaching the bolt, and disconnecting the electrical plug, which is often done by feel. Many DIY videos are available to guide you.
🎬 Watch this step-by-step guide to replacing the sensor yourself.Are there any recalls for this part?
No. There are no active recalls from Porsche or the NHTSA for the crankshaft position sensor on the 2004-2008 Boxster models.
Will a bad sensor always trigger a Check Engine Light?
Not always, especially in the early stages of failure. It's common for the sensor to fail when hot without setting a code initially. However, a complete failure will almost always trigger a Check Engine Light with codes like P0335 or P0336.
🎬 See how to troubleshoot a P0335 code and no-start condition.What's the difference between a crankshaft and camshaft sensor?
They perform similar functions but monitor different parts. The crankshaft sensor tracks the main rotation of the engine from the crankshaft. Camshaft sensors monitor the rotation of the camshafts, which control the engine's valves. Both are critical for engine timing, but a failed crankshaft sensor is more likely to prevent the car from running at all.
Helpful Videos
Technical Specifications
OEM Part Numbers: 99660611203 98660611204 98660611203 98660611202
This is a Hall effect sensor that reads the position of the flywheel. It is located on the passenger side of the engine, near the bell housing where the engine meets the transmission. It is secured by one M6 bolt, which can be a 5mm Allen or T30 Torx head.
We Have This Part in Stock
The information in this article is provided for general reference and educational purposes only. Vehicle specifications, procedures, and part compatibility can vary by production date, trim level, and region. Always consult your vehicle's factory service manual and verify part numbers before purchasing or performing repairs. Safety-critical components such as airbags, seat belts, and braking systems should be installed by a qualified professional.
- Porsche Boxster: