X51 GPU Overheating

I ordered an X51 Alienware system back in June. I got the i-5 processor model with the 8GB RAM, GT 545 GPU, 330W PSU, and 1TB HDD.

Late last week I decided to upgrade the video card. I bought a PSY GT 660TI, hearing the 660TI is a compatible upgrade for this system from various sources.

Well, I installed it and everything seemed to work fine. I updated the drivers, and then decided to play a few games. However, after about 20 minutes of playing, my FPS would drop dramatically from 60 to 20 during heavy load. The sound would crackle, and the entire system would become sluggish and slow. I checked the system temperatures and GPU stats, and I discovered that the CPU was running at about 60 Celsius and my GPU between 80 and 90. Furthermore, the GPU load was over 90% during these events and my power consumption for the computer was at 97%. I also should note that I was testing Civ 5 in this scenario and would have no problems running this game with my old GT 545. 

I tried removing all drivers, cleaning the registry, and reinstalling the most-up-to-date driver. This did not fix the issue.

I took off the side panel of the machine and tried to play games and it works. The GPU temp drops to around 60 and I can play fine and the power consumption drops to 30%. Obviously this is a heating issue.

Has anyone else had issues like this before? Are there any cooling solutions that could help, or should my system not get this hot to begin with?

Thanks.