Mercedes Crankshaft Position Sensor (CPS) DIY Change on R129, W124, W140, W201

In this video I show how I replaced my crankshaft position sensor (CPS), describe common faulty symptoms (bad warm starts), what it does and a simple test.

The main symptoms of a crankshaft position senor are a poor warm start condition (or no start), poor engine performance, acceleration issues and poor fuel economy. The CPS is considered a regular maintenance item and is meant to last 100,000 miles (160,000 km), or 10 years. This is a simple DIY on most Mercedes.

A CPS can begin to malfunction as it heats and this is common as this part is often original. The CPS is located on the car's flywheel and is used to measure engine speed with the timing of fuel delivery. It's a critical part in the starting of your car, keeping the engine on and general engine performance including acceleration.

Another name for a CPS is a crankshaft angle position sensor.

The video and part applies and is helpful to many Mercedes-Benz including: R129 SL (300 SL, 320 SL, 500 SL, SL 600), W201, W124, W140, including models 260E, 300E and S320.

Mercedes Part number 300SL (1990 to 1993), 320 SL (94,94), some W124, some W140: 002 153 9298
Mercedes Part number for 500SL (1990 to 1995), some W124, some W140, some W201: 003 153 0128
Tools: 5mm Allen head small screwdriver, socket set
Always check exact part fitment for your vehicle

Car shown: 1992 Mercedes-Benz 300SL with engine M104.980

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Disclaimer - The content of this video is available for informational and educational purposes only. It is not intended to be a substitute for professional advice. I do my best to provide accurate and complete information, however, I assume no liability for any property or personal damage that may arise from any of the information contained in this video. Due to factors beyond the control of Handy Val, no information contained in this video shall create any express or implied warranty or guarantee of any particular result. Handy Val always recommends safe practices.