Ford Focus weak / no heat at idle

[The_Eric]

Cooling system vacs are not the end all, be all way to fill a cooling system. They do drastically reduce the chances of an air lock, but you can still get them. Been there, done that.

 

[mk378]

You really should flush the heater core. Drain the system, disconnect both heater hoses, hold a garden hose up to one hose at a time to flow water through the core in both directions. If that doesn't solve it, at least it will rule out an obstructed core.

 

[ram_man]

Originally Posted By: mk378
You really should flush the heater core. Drain the system, disconnect both heater hoses, hold a garden hose up to one hose at a time to flow water through the core in both directions. If that doesn't solve it, at least it will rule out an obstructed core.


That's what I'm getting ready to go do car has been maticulously maintained but maybe it is clogged up some almost would have to be based on the symptoms.

 

[ram_man]

Flushed the heater core twice with clr I have 165 degrees whil driving and while idling it cools down slowly to 125 not optimal probably but a lot better than it was .

 

[JamesBond]

How did you flush it? How did you get the clr in the heater core? Thanks.

 

[ram_man]

I unhooked both heater hoses and back flushed it using a hose with a spatter attachment. Then I used a transmission funnel and poured clr down the hoses until they were full and let it sit for 10 minutes . No longer than that!! It's hard on aluminum