WEAK POINT EXPOSED

My 2012 Mercedes C200 with 99,000km had its “check engine” light come on. A stretched timing chain was diagnosed and it needed replacing alongside many interacting parts. It cost me $5536. I thought a timing chain, as opposed to a belt, was supposed to last forever? Greg Blundell, email

My European car specialist mechanic said it would be a “reasonable expectation” the timing chain should last the life of the car. But he explained it’s a known weak point on this era and model Mercedes. “The chain runs at the back of the cylinder head and the bellhousing area so it’s a big job. The engine and transmission need separating to get access. I’ve seen some last a long time, others I’ve seen going at 120,000km. It’s quite common for that era of European car – not just Mercedes – to have these weak points as they made some moving parts smaller in the quest for efficiency.”