freelander lost power

driving to get shoppin it lost all power. i got there where mrs was as aa arived. he diagnosed either belt slipped a tooth or head gasket failed. im talking to mrs it didnt overheat was below half on gauge. so when i got home i looked at timing belt. on aligning cams then checking crank pully it is just off mark( slightly to the left) but doubtfull its a full tooth out. has anyone experienced similar

What engine have u got?

1.8 k series 55k

think i will get cam cocking tool, and recheck positions of pully. then if ok do a compression test. and work from that. but given it didnt use water or overheat and i had previously had a fault wi dodgy temp sensor its beginning to be a pain