The key in the ignition to my mercedes 2002 c320 will not turn

SOURCE: 1999 Mercedes Benz CLK Old and New Key will not turn ignition

hi,seem your esl or electronic steering lock mechanism is defect,since you replaced with key,ty

SOURCE: 1995 Mercedes Benz C220 will not start, and key

hello,steering lock mechanism and your key need to replaced,if you want try to remove your under dash,steering lock mechanism have a small pin(around 5 mm) which pit to steering housing,drill out the lock,then try to turn steering wheel,ty

SOURCE: I put my key in

There's a good chance the key is worn or the ignition lock. If you don't have another key you can order one through a Merc dealer via the chassis number.

Cheers John

SOURCE: 2002 MB C320 gas cap problem

I had the exact same problem, went to the Mercedes dealer and they fixed it for free with a pair of pliers. They just pulled up the metal clips and turned them back into place.

SOURCE: Mercedes Benz c220 ignition will not turn.

Did you try jacking up the car at the front then wiggle the steering as you turn the key? Did you try a spare key? Spray inside the mechanism with WD40. Try putting the key in at different depths and turning.
The lock cylinder is a replace only item.