No, they are made of an Alloy, Grey Cast Iron. So you are both right.
"The cylinder block on the 1.4l TSI engine is made from grey cast iron with lamellar graphite. This guarantees sufficient operating safety at the high combustion pressures of the TSI engine. Due to the high strength of a cylinder block made from grey cast iron with lamellar graphite compared with one made from diecast aluminium, the camshaft may be removed."
Wikipedia Grey Iron
I guess the term alloy was being transposed/confused with aluminium.
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