Expert: Sean Halliday - 1/9/2009

Question
no heat temp gauge fluctuates extreme high to low. i tried to bleed air out of coolant- no coolant from thermostat bleed hole. replaced thermostat- no change.

Answer
The problem could be a worn out water pump or blocked system.I would not let the engine run to very hot as it may blow the head gasket.Drain the complete system,remove the lower hose and flush the engine by running a hose the opposite way thru the cooling system.Have the top hose in a bucket or similar set up.See what comes out.You will need to remove the thermostat to do this.