i have recently bought a rs cabbie and it has a few problems, first off the heater controls dont work, there is no boost on the turbo (no vac leaks) and a rather loud tapping sound which has only just started, and also the car overheats when driving slow, i changed the thermostat and flushed the rad

 

try the acuator for the boost problem and check to see if the fan is cutting in, if not change the fan switch.

 

the rad runs off a switch in the car and is constantly on, been told the head gasket might have gone. sorted the actuator had come loose and the split pin missing, cheers any1 no the gap for the tappets?

 

are you running a special cam if not they are hydrolic (self adjust)