I stopped on Friday with my beloved 309er on the highway (oil temperature went up and oil pressure down), motor runs in empty run, but goes off with the gas giving. compression is ok, a plug is a little rusty and a valve has fire tracks. open the engine in the workshop costs already from the beginning about 300 euro ! !! in addition, the repair in unknown height … it is a 309 gt, bj 88 with 1598 cbcm and 104 ps. what could be the error ? worth it d ie repair ? thanks for your help sven