1. Air pump burning out. This is the stupid $400 Bosch air pump that kicks on when the engine is first stated cold. The pump sends air into the manifold to dilute the rich air/fuel mixture when the motor is cold. You can thank the EPA for that one... it dosen't actually purify anything, rather just tricks the computer to "think" it is burning cleaner... anyhow, there is a recall for the relays that operate the air pump, and they stick open causing the pump to stay running and burn out. The $40 relay burns up a $400 pump. Replacing the relay and pump are very easy, just expensive. My CL 55 got the first pump covered under recall, however I have replaced both all over again
2. Many people seem to have numerous ABC issues.
3. Sludge issues. Follow the 10-15K mile oil service intervals and you are sure to have this problem. I dont care how "synthetic" the oil is, no car should go past 7500 miles between oil service and filter changes... especially the 55 Kompressor cars.
4. Trasmission control module leak. On the 55 cars, there is an o-ring update that prevents oil leekage from the contol module housing in the transmission. Very cheap in parts and worth the fix.
Other than that, I have experienced very little issues with CL's. My family and I own a luxury car dealership and are partnered with a neighboring Mercedes/BMW/Porsche repair facility therefore I have owned several of almost all the late model german cars. My car of choice is my CL 55 AMG Komressor. Like most anything, if people keep up with the maintenance and service on thier CL's, they are fantastic cars! It all comes down to buying a nice one to begin with (not wrecked, salvaged or neglected). Most people who chase the ultimate "deal" on high end cars are the ones who end up with a cheap buy with expensive problems. You get what you pay for. Always request a PPI before buying at least so you know what to expect the car will initially need to get the car up to par.
With all of that long winded experience, here are the overall rules for keeping an overall happy CL in my experience.
1. Frequent Mobil 1 Synthetic Oil Services.
2. Change Transmission oil at around 75K or 5 years.
3. Always Keep clean air filters.
4. Keep good, mercedes brand belts on the car.
5. Align all 4 wheels immediately after tire replacement.
6. Brake fluid flush every 2 Years.
7. Cabin filters anually.
8. Keep sunroof track lubricated.
9. Coolant flush every 3 years.
10. Change Spark Plugs around 75K - 100K miles.
11. Avoid automatic car washes. Hand was car with car wash soap and wax at least ever 3 months. Use Lexol Leather conditioner for interior leather.
If you follow these 10 steps, you may never be able to complete a list of 10 problems, just 10 steps to preventative maintenance.
Sorry for the lengthy post, I just love CL's and really appreciate nice, well cared for automobiles after being in the business after so many years. (you wouldn't believe the junk some people let thier cars become).
Please feel free to add if anyone thinks I have Missed some important issues.
Happy Motoring
