2005–2008 Mercedes-Benz C300 / C350 / E350 (and more): known reliability problem

The problem

M272 V6 / M273 V8 — balance-shaft / idler-gear wear on early (pre-facelift) engines.

Vehicles affected

Mercedes-Benz — C300, C350, E350, ML350, CLK350, SLK350, R350, GLK, model years 2005–2008. Adjacent years and trims with different engines are generally not affected; the exact engine/transmission in the specific car is what matters.

What it means for a buyer

This is a real, documented pattern — but often preventable or already addressed. It is a reason to inspect harder and negotiate, not necessarily to walk away: a car with records showing the issue was serviced can still be a good buy. For context, a Mercedes-Benz averages about $908/year in maintenance and typically retains roughly 44% of its value after five years.

Considering one anyway? Do this

• Ask directly whether the affected component was repaired/replaced, and get the paperwork.
• Get a pre-purchase inspection from an independent mechanic and mention this exact issue.
• Check open recalls by VIN at nhtsa.gov/recalls.
• Pull the free government title history (salvage/flood/odometer) at the NMVTIS portal.
• Price it against unaffected rivals — this issue is negotiating leverage.