Fuel injection computer takes the signals from both the cam position sensors and crankshaft position sensor and calculates when to fire the fuel injectors and spark plugs. The sensors also work in conjunction with the variable cams. If the camshaft position sensors are not operating properly, your car will run very erratically or perhaps not at all.So here I want to share the procedures to replace camshaft position sensor for Mercedes Benz.
Time: 1 hour
Tab: $40 to $900
Tools: E8 Torx, small flathead screw driver
Parts Required: New camshaft position sensor
Hot Tip: Clean the area before removing the sensor
Performance Gain: Better control of fuel injection and engine timing
Complementary Modification: Replace crankshaft position sensor
Applies to: C350 (2007-14), SLK350 (2004-14), CLS350 (2004-14), CLK350 (2005-14), E350 (2005-14), S350 (2005-14), SL350 (2005-14), R350 (2006-14), ML350 (2006-14), Viano (2005-14), Sprinter (2006-14), CLC350 (2008-14), GLK350 (2008-12)
To replace the camshaft sensors you will need to remove the front engine cover (red arrow) by pulling it straight up from the front.Remove the two air intake ducts by compressing them in off the air filter cover then slipping them off the ducts (yellow arrows).Please check the engine cover removal post:How to Remove Benz C Class W204 Engine Cover
The four sensor are located on the end of the cam housings on the cam housings on each head (yellow arrows)
On the left side bank you can remove both the intake cam (red arrow) and exhaust cam (yellow sensor) without removing any other components.Note:the oil cooler and power steering reservoir have been removed for other jobs;you do Not need to remove them to replace the sensors.
The clips on the electrical connections are simple squeeze in and pull up connections but the tabs (red arrow) get very brittle and will probably break when you remove them.If the tab breaks do not worry,just make sure the connections are properly seated when reconnecting.
A single E8 Torx holds the intake and exhaust sensors in place.
With the bolt removed you can pull the sensor from the head.
With the sensor removed check that the mounting surface is clean and flat (red arrow) as well as have a look inside the port to make sure there is nothing that is blocking the magnet from sensing the cam.
If you are removing the sensor to perform other work and reinstalling it always replace the O-ring to prevent leaking oil (red arrow)
On the right cylinder bank you can see the intake sensor (yellow arrow) and the exhaust (red arrow).You will need to move the air switch over valve (green arrow) out of the way of the intake sensor.
Using just your hands release the plastic tab on the back of the switch over valve (red arrow) and slide it off the mount (yellow arrow).You can now remove the intake sensor.The procedure for the sensor removal and replacement is the same.Installation is the reverse of removal.