One problem related to engine cooling system has been reported for the 2003 Mercedes Benz C230. The most recently reported issues are listed below.
2003 mercedes C230- purchased new- bought extended warranty. Have followed maintenance program religiously. Last b service was Dec 4th-$900. 00 on Dec 27- car completely died & smoke coming out the back- coolant light on. Towed to closest dealer- they can't tell me why it happened but- the spark plugs soaked w/coolant, #2 plug smashed on top, #2 cylinder intake valve bent & broken. #2 &4 pistons damaged. Even though extended warranty is up- mercedes will not stand behind the car- say can not pin point a mfg defect even though this rarely happens even with high miles- Mercedes Benz usually can get well over 200,000 miles. Now cost is $8,000 to put in rebuilt motor or $11,000 to repair damaged one- something had to cause this- there were posts on your site from 2003 regarding engine & cooling issues but could not find more detailed info- NHTSA item# 10002965- do you have more info or give me advice?.