Kosciuszko reported an oil pressure problem at the end of stage eight, which intensified during the following run, which he completed with a time that was almost one minute slower than overnight leader Nicolas Fuchs.
Guerra said: “He crashed with a big stone in the second stage and has problems with his engine. I know he was having problems with his oil pressure and I think the engine is broken. I am very sad for him, he’s a very professional driver.”
If Kosciuszko - who topped the PWRC drivers’ standings prior to the start of the event - is unable to continue then Fuchs will take a lead of 1m06.3s over Guerra into Saturday afternoon’s trio of stages. Ukrainian Valeriy Gorban will move into the final podium position with local hero Marcos Ligato climbing to fourth following his day-one exit.