About 18 months ago I was driving my car and all of a sudden it could hardly be driven. I limped into my local dealership and they determined that I needed a new catalytic converter. The converter on the driver's side was totally clogged. After they told me it was going to cost about $1,500 I took it home to do it myself. While speaking with converter sales people I learned that the part was covered by an 80,000 warranty. I then spoke to Mercedes Benz customer service and they too agreed that the converter was covered. I then had my dealership call the customer service and then they replaced the converter under the warranty. As soon as I brought my car home with a new converter I noticed a ticking noise in the engine. I was sure the converter problem has something to do with my problem. Noone at the dealership thought the noise had anything to do with the converter problem. I then took my vehicle to a shop that strictly works on MB. After listening to the engines he said it was probably a bad oil tube. I have since replaced two oil tubes, however the noise never went away and keep getting louder. Recently I told the shop to do what ever was necessary to find the problem. After trying a variety of fixes and not finding the problem, they pulled the engine. He told me today that he could tell the 1st and 3rd cylinders on the driver's side had been exposed to extreme heat and had been severely damaged. He also commented that he was convinced that the original damage was done by the clogged converter. Interestingly he has worked on MB for 30 years and never had a situation like this one. All the rest of the engine is in excellent condition.