December 2018

M271 – Cam Magnets Leak Fix

In 2002, Mercedes-Benz of Germany released the M271 engine in a vehicle for the first time, the W203 C200 Kompressor, to replace the bullet-proof M111 engine, which had run in many different iterations from 1996 up until 2006.

Built in the Mercedes-Benz engine plant in Stuttgart-Untertürkheim, Germany, the M271 family of engines are 4-cylinder double overhead cam driven by a single roller chain, with an aluminum block with cast-in iron liners, 4 valves per cylinder, variable valve timing for exhaust and intake and a cast aluminum cylinder head. It began life with a supercharger then switched to the more efficient turbo in September 2009.

Since the turbo did not require engine power to run the compressor, it was more efficient, had lower production costs and was 4kg was lighter. This new updated M271 was offered first in the W212 E250 CGI BlueEfficiency.

The M271 has many positive points, but as with most motors, there are some negative points. One of the main problems we have found here at Alan Lennox Motors is with the VVT cam adjusters (magnets). These magnets sit at the end of the camshafts and vary the timing according to numerous factors. The problem we have found is that over time they begin to slightly leak engine oil. This oil causes numerous problems, the main problem is that once they begin to leak, the oil runs down the internal wiring of the loom. Over time the oil surreptitiously works it’s way through the loom and damages other sensors like the O2 sensors in the exhaust system. This can be a costly job, the oil will also eventually damage the loom itself which is a very costly part through Mercedes-Benz.

Cam adjusters themselves are not overly expensive, but as mentioned above, satellite problems concerning with the leak are. Here at Alan Lennox Motors, we can fit a mod, a small blocking loom that connects to the cam magnets, so that if they leak again, the mod will arrest the leak. This is a fairly inexpensive fix or preventative measure that can be undertaken.

Small measures like the M217 Cam Adjuster Mod can save you money and give you piece of mind.