heater core swelled

[rrelco]

any help on why this happened? this is about 6 years old

[TheJDMan]

Without knowing any of the back story, my initial thought is that it froze.

[rrunner68]

Lots of stuff.. Could froze, lifted a head, head gasket leak, all kinda of fun stuff.

[rrelco]

Freezing is out...the car lives in California. i really think its a pressure issue water constantly is passing through it even when i have been racing at willow and Auto-X it on hot days. so i found a pressure reducer valve in-line on the 3/4" hose and see if that works.
Dan W why would a head gasket cause that! if that is the issue there would be no pressure i would think

[rrelco]

figured it out! when i bought the car the hose diameter was incorrect manifold to heater core s/b 5/8 not 3/4 so hot water was entering at top not bottom so thats what i think happened