Four problems related to engine have been reported for the 1996 Toyota T100. The most recently reported issues are listed below.
Head gasket.
Heard a loud rattle in engine. Disassembly discovered broken head of connecting rod bolt. Resulted in damage to connecting rod bearing; requires engine overhaul and piston/ connecting rod replacement. Extremely expensive.
Engine head gasket faiiled, resulting in a fuel leak.
Engine head gasket malfunctioned.