I probably went the first 6-7 years before the heater core clogged up the first time, then 2 years, now it seems every year I have to flush it out before it works for the first time when it gets cold.

Is there a simple solution to keep this from happening? I don't think there is a valve anywhere so isn't water circulating through the core all the time even in the summer when the heat is not on?? If there was I guess turning on the heat a few times during the summer would keep it from clogging.
Sure is a pain getting the hoses on/off way under the cowl to flush it.

 

I find it easier to take the hoses off at the water pump. Then you can flush the hoses as well as the core. I theorize that the inline flow reducer may have something to do with the clogging. I have only had to flush mine once in 9 years and that was after I had left the system open when the engine was out.

 

I thought about that, but figure if I removed them at the pump I'd have alot of spillage then, wouldn't the block drain down to the point where the hose connected to the pump that way?
And the fact my top hose connector the way it was positioned would require me removing some other hoses. At the firewall they are so high there is very little spillage of coolant.

 

Replace it. It went 7 years the first time because it was new. No scale, rust or corrosion was in the coils at that point. Now that it's old there is, and flushing will only open up part of this blockage, and never get it back to new. Once it's replaced it will go another 5+ years before it will need flushing.

Another thing that people run into is lack of maintenance. Cooling systems are neglected a lot of the time. Unless it's kept up with, it will be come more of an issue.

 

My 93Z has never clogged????????????? Maybe I lucked out????? But I do flush the system every other year.....

 

mine wasn't so hot, so I flushed it at the water pump and nothin really came out. But afterward it worked great...heat is nice and HOT. I guess maybe an air pocket was in there.