Hi, does anyone have any idea what goes into this and the potential cost? Any advice will be appreciated.

 

Hi and welcome to the forum.

Most head gasket jobs include having the head and maybe even the block resurfaced. Did the car overheat? If you don't have that done it will likely not seal good for a while. I spoke to a guy the day before yesterday that had the head gasket done twice on the same car this year because he refusses to pay a shop to resurface the head.

My guess would be that you're looking at a cost of about $2,300 if you pay to have it done, $1,100 if you pull the motor apart yourself.

 

What happened to require a head gasket?

 

To resurface the head is only required if its warped which can occur when the engine overheats extremely or tightening the bolts in an improper order.
The good question is as Hudini said what did exactly happened?