That would be wise to do. With temperatures that hot, it can damage the card and by extension the rest of your computer.
mine was now at 90 C when i didthe gpu z render test
That is still a high temperature, as is anything about 88 C.
Try get a aftermarket cooler for your GPU and see if you can get better airflow throughout your system!
That will drop your temps a lot through out the system.
If you do plan on getting an after market cooler, first check your card to make sure it isn't damage around the mounting holes as that may render the cooler useless. I would just have it RMA'd since you know that something is physically wrong with it before you spend more money on it.