Problem with my graphics card

So, I have a Sapphire Geforce 310 512MB in my system. When I turn it the PC on, it takes no more than 5 minutes until the card is burning hot, at around 77-83 degrees celcius.

I decided to take the fan off of the PCB, and noticed that there wasn't much thermal paste on, so I cleaned the top off and put a bit on, put it all back together and turn on the system. It didn't fix the problem.

Any thoughts on how I can solve this?

I would of just bought a XFX Radeon HD 7770 until I had the funds to build a new, better system, but I'm currently buying a motorbike and I need the cash.

sure the fan is spining? is there ventealtion in your case?

I didn't think the fan was spinning either. I restarted the PC and watched it, and it span up like normal. Not a fan problem.

The ventilation is, well, "meh".

The case is an AX3300 from Acer, and it's freaking horrible. It only has one 120mm in-take on the side for the CPU heatsink and a single 40mm rear vent from the power supply.

The graphics card is at the top of the case upside down, because the motherboard mounts the other way, if you know what I mean.

No room, bad cable management, etc...

Clean the dust inside the cooler using a air pistol.

seems like you have a ventelation problem, all the hot air from your whole system is building up at the top where your gpu is.

It's been like that for 3 years, only a few days ago this has started.

And my system is relatively dust free.

can you check to see if something is using your gpu?  malware bitcoin mining maybe?

Hmmm, interesting. 

I'll scan my PC.