Conecting Rod fused in a 156 2.0 TS
I've got a 156 2.0 TS (140.000km) and last month driving on a highway in Spain (Barcelona to Zaragoza) the engine was broken down. The concting rod (piston/cranckshaft) became fused, baking the engine body. A week ago the car was at the garage for checking (replace oil filter and oil). The car has been checked as detailed in the maintenance book, but ALFA SPAIN only reports it's out of the warranty period.
After disassembling the engine, they report some oil particle has blocked the oil outlets, and that's the reason why the conecting rod became fused.
But I'm asking about the reason why this particle was sucked by the oil pump and was not filtered by the new oil filter.
If anyone could help me from the technical standpoint I'd appreciate. Also I'd need to know who may I address a complaint letter, cause ALFA Spain is not doing anything at all.