coolant problem

[bimmer325]

Hey guys.
I have a 2001 530I.
my rad was leaking the other night. so I replace the rad.
after the rad replacement. the expansion tank blew up for no reason.
it seem like the system is building too much pressure and blew the resevoir to
pieces. I'm wondering now is, why my rad blew on the side the first time?
Have anyone experience the problem I'm having. Is my rad cap bad, causing the pressure not bleeding out?
please help....

thanks.

[marek]

You have one of two likely causes. Bad cap not venting the pressure or worse a blown headgasket causing this. I would replace your cap ASAP because it can also lead to a blow headgasket.

[denisemichel]

what ever you do dont let the headgasket blow! lot of $$$ to replace, take it to a mechanic ASAP!.

[Gamite]

did the rad blow from the neck? It's common.

[myndgone]

Originally Posted by Gamite

did the rad blow from the neck? It's common.

expansion tank is common also....