What are some common issues with the Ford S-Max engine and how can they be fixed?

I just bought a used Ford S-Max and I've noticed some issues with the engine. It's making a strange noise and the fuel efficiency seems to be lower than expected. Could this be a sign of a bigger problem and what should I do?

It's possible that the strange noise and reduced fuel efficiency are symptoms of a problem with the engine. I would recommend taking it to a trusted mechanic for a diagnostic test and repair.

I had a similar issue with my Ford S-Max and it turned out to be a faulty spark plug. I replaced it and the problem went away. I would suggest checking the spark plugs first before taking it to a mechanic.

I would also recommend checking the air filter and oil levels. Dirty air filters and low oil can affect engine performance. Keep up with regular maintenance and these issues should be minimized.