My heater core has been replaced 2 times already and I think it needs to be replaced again, whats the problem?

Heater cores are fragile. To remove the hoses, you must cut them off or you will break the core, and when you put the new hose on use a little lubricant on the tubes so the hoses go on easly. The hoses that come from the core to the engine if allowed to bounce up and down will over a period break the tubes that go into the core. They must be tied up and/or supported to something that doesn't move to stabalize them. If they are too short, and don't have the room to move with the engine, and not move with the body, then they will break the core. What I mean is: attach the hoses to the fender somehow to keep them from moving up and down on the core side, and as the engine moves up and down with taking off and stoping they need to be able to move with the engine on that side of the hoses. This is not some mystery or an incompetant person installing the heater core. If it worked ok when it was installed, and a year later starts leaking, then how can one blame this on the installer? A lot of times it will be the hose clamps are loose and needs tightened up at the core. If they are too loose, then coolant can trickle down the pipe to the inside of the vehicle and cause what looks like a leaking core. Check these clamps first, and if they are tight, then suspect a bad heater core. I have also seen a core that is not sitting inside a cushion mount and will allow the core to viberate and move around, and after a while causes the core to start leaking. Changing the heater core is the fix, but one must also look for the cause, and fix this as well. If you have been through two cores in a short period of time, then I would think you have something else going on to cause this.

Glad I could help. Good Luck!!!

There is a high probability that you are dealing with electrolysis in the coolant system. A good chance that there is a poor electrical ground in the radiator and the engine. This is the most common cause of electrolysis in the cooling system.

If you have a DIGITAL volt meter, connect one lead to the metallic part of the radiator, and dip the other end in the coolant through the radiator cap. It yo see ANY voltage, yo have located your problem.

This time when you replace the core, completely flush the coolant (NOT with a flush, but with FRESH water) until ALL of the old coolant has been removed.

Locate the failed ground connection(s) and repair them.

If you can locate a Truck Parts store, or a GOOD quality (e.g. NAPA) parts store, purchase a bottle of NALCOOL or WIXCOOL and use according to the instructions. Mix fresh coolant 50% / 50% with water.

After the repairs, periodically check the coolant voltage level and keep it < .025 V.

Good Luck and Merry Christmas

Try using the stuff that can plug holes and see if that does the job to get you by that has worked for me.

To prevent it from happening, make sure your maintenance place is just doing a drain and fill.

Two of the cars I have owned have had their cooling system damaged including the heater core by "Flsuhing"

Sounds like you have a leak some where. I would get your cooling system pressure checked. and get that leak fixed before you have the heater core replaced again.

Maybe you should of told us what kind of vehicle you have. Also quit buying cheap parts from auto zone and have it installed by a reputable auto technician.

It sounds like you have a LOT of engine sludge.

Whoever did the work sounds incompetent,did you get any kind of warranty???