Is there a poduct you can buy to unclog heater core in your 2002 mercury sable?

Answer 1

Do not try using compressed air to blow the clog out. Now here's how you do it: Prestone makes a reverse flush kit (about $10), available at any auto parts store that is relatively easy to use and can help break up the clog and clean out your system.

You will need to drain the old coolant, cut and put a "T" in the heater core return line, a sharp box-cutter is the easiest way, be careful not to cut your fingers, and make sure there is enough hose on each side of the cut to clamp the "T", hook up a garden hose (low pressure, not full flow) and flush the engine. To clean the system a little better, they also sell a system flush chemical, if your system is in fact clogged, spend the few extra bucks for this.

For all of this, follow the directions carefully, and DO NOT drain your system or attempt to splice any coolant lines with the engine hot (consider it hot if it's very warm to the touch) or you can severely burn yourself, end up permanently blinded, or worse. One part of this procedure will involve running the engine with a garden hose attached to that "T", make sure your hands, the hose, and anything else will not come in contact with any moving parts.

Note; the "T" will stay on your line when you are done and if you follow the directions, make a clean cut in the line, it will not leak. I've used them for years with no problems.