Does the 2011 Kia Optima have a timing belt or chain?

The 2011 Kia Optima does have a timing chain. You will come across many issues with an engine. A spark plug may pop off, causing engine trouble. A gasket may be loose and that needs to be tightened up quickly. You can have oil leaks and those need to be fixed as soon as possible. A serious problem is the engine overheating. This may lead to fires and the vehicle exploding. There could be excessive oil use, requiring the oil to be changed sooner than expected. The coolant needs to be changed every 60,000 miles. Your air filter needs to be changed every 15,000 to 30,000 miles. The spark plugs need to be replaced every 100,000 miles unless it's a copper one. A cooper spark plug needs to be replaced every 30,000 miles.