When I bought my '91 RS with 87k miles in August it was leaking antifreeze into the passenger floorboard when the car was running. I replaced the heater core about 4-5 months ago and the problem stopped. Now, the problem has started again and is just as bad, if not worse, than it was last time.

What are some outlying problems that could be causing this? Should all of the hoses be replaced? etc.

Thanks for the help!!

 

My guess would be that it blew again since the core itself is the only piece inside that carries any coolant. As you already know, all the hoses & clamps are outside so that only leaves the core itself to leak (again).

 

Is there any reason you can think of why the heater core may be busted again? Could there be something on the outside affecting the heater core and making it leak?

 

Other than the hose clamped on & squirting towards the firewall & getting in that way, busted core is all I can think of but then it would be a lot of water compare to where a cure leaks.

Have any trouble getting the new core in & possibly twisted a tube cracking/weakening the welds & causing it to bust? Something they are tricky to line up into both holes so it wouldn't surprise me that much.

 

I had a dare i say it, a mustang that ate heater cores and after about three of them a mechanic told me to hook ground wires to all body parts. hood, trunk exhaust,block,frame. It sounds crazy but it worked and I never changed another heater core. The antifreeze turns to acid somehow and since heatercore is thinner than radiator its the first to go. maybe something to try.

 

Def a broken heater core... maybe try an oem part this time?? Also that is true that antifreeze will carry voltage. Test it by placing the positive terminal of a volt meter into the radiator and negative to battery ground.. another good idea is flushing the cooling system with water prior to replacement.

 

Make sure you do check your clamps on the heater core cause that will cause antifreeze to spray into the cabin