Pontiac Repair: Heat problem, montana sv6, speedy lube

Question
QUESTION: My 2007 Montana SV6 wont make heat at idle but once the rpm's are up its fine. Is my heater core plugged up? Is the core difficult to replace or is there a product I can add to the coolant to clear it up?

ANSWER: Hi Kim:

for the front heater or the rear heater? If it's just for the rear this is a common issue and it's just the way the van is the hot water has to travel 15' away from the engine to the back of the van to heat it up. If it's from the front it may just need a thermotstat and possably a heater core black flush. I have yet to see a core need to be replaced on one of these for this issue.


---------- FOLLOW-UP ----------

QUESTION: Ok thank you. It is the front heater. Is a back flush something I need a mechanic to do or a place like speedy lube? Is it expensive?

Answer
No it's not expensive and it's pretty easy too. all that needs to be done is the hose for the heatre core be disconnected and with the use of a garden hose run the water through the heater core the reverse direction that the water flows though it. I would have the thermostat changed as well as I stated before.