i was driving along when vehicle cut back from about 4000rpm down to 2000rpm I tried to drive through it but it wouldn't pick up again i pulled in switched it off and the r wouldn't fire up again. Any ideas whats wrong? Had some of the dash out doing the heater matrix but there is loads of coolant in the system. when ignition is on there is a ticking noise coming from the engine. Any help would be much appreciated.