so mine is clogged and need to know if it can be flushed in the car or if you must take it out to do so? just need to know since i dont want to take it out and would just bypass the heater core.

 

It can prabably be flushed in place, since the two connections for the heater core are accessible in the engine bay. You'll need to make sure the heater valve is fully open by moving the temp lever to hot while the ignition is on.

How do you know it's clogged. If you have no heat, there are more likely causes...

 

Yep, and I always use distilled water to add to the anti freeze when filling my system. That way the minerals that are in ordinary water don't build up and cause problems later on AND Put a tablespoon of Baking soda in the system to keep the PH from going acidic thus preventing acid eating the core.

 

cool. but i know its clogged since the lines going in is hot and the out line to the motor is not? if im wrong please correct me

 

and i can hear the valve open and close when moving temp cold to hot