Coolant backing up into expansion tank

[Karlecc]

Can anyone advise me on my coolant backing up in to the expansion tank then causing it to overheat seems to be when I've been revving hard tia

[DaveRAC]

Could be running too much pressure in it and really and truly the only thing that can cause that is compression leak from head gasket 

 

Any modifications to vehicle at all and what model do you have ?