Yes they can be however I've sold dozens of cars with these engine and no problems. I only buy them with FSH and low miles. They need regular oil changes to keep the oil pipe clean to the turbo. Oil changes should be done 8-10k miles. The only problem I had was the oil seal on the oil pump which was a big job for a 50p seal. When buying any car with this engine Ford/Mini/PSA look underneath at the under tray and check for oil dampness in the corner near drivers foot well is a give away.