Hi All,

I have not owned a Mercedes since my 1972 220D. A year ago I've purchased a year:2000 C280. When I bought it, the harmonic balancer's rubber was already somewhat off making the pulley wobble. I ordered the new balancer from Phil but have not had the resources (time mostly) to replace it, I've merely spent a couple of minutes wondering where the tensioner of the belt is (I did not see any obvious way to loosen the belt). So, the first question set deals with the crankshaft pulley's removal and replacement:
- What size Allen wrench do I need to loosen the bolt that holds the pulley?
- How do I remove the belt (where to loosen the belt's tension - what provides tension to the belt)?
- I bet that the bolt is stuck pretty well, I used to remove these bolts (on Japanese cars) by suspending a long wrench and shortly cranking the engine - would this work with the C280 too?
- What is the torque spec for tightening the bolt? Do I need to use thread locker fluid?
- What is the process of correctly determining the tension of the belt?

Then, I will need to replace the lower right front control arm. Is there additional weight needed on the wheels when tightening the bolts in the bushings or will the weight of the car on a level surface do it? Any hints?

Third: My check engine light's on showing problems with the front O2 sensors (why did they have to put 4 O2 sensors in these cars? ) . Removing the rear O2 sensors do not seem to be extremely hard, but what everything do I have to remove to get to the front ones? Any hints replacing the front O2 sensors? (Is there a compatible Bosch aftermarket O2 sensor that does not cost a leg and arm?)

And finally, Is there an easy way to set the climate control and the instrument cluster to show the temperature in Celsius?

Sorry that it got long, thanks for your patience and possible answer.