You can never be sure what the problem is but I cannot say to you 'yes 80 degrees idle is perfectly fine :/', god knows what temps it must reach after some heavy gaming.
I don't understand how you have the card at 80 degrees idle, my friend had a bog standard 4870 from powercolor and it was around 40-50 idle, gaming probably never touched 80. I want to know how you are achieveing 80 degrees idle tbh, if your case has great airflow and the cooler on the gpu is not blocked with dust then I can only assume there is poor contact between the cooler and the gpu. You should have RMA'd the card when it was still in warranty, regardless of whether it was crashing.
Having a card at 80 degrees constantly whether 1,2 or 3 years could cause many problems.
I don't understand how you have the card at 80 degrees idle, my friend had a bog standard 4870 from powercolor and it was around 40-50 idle, gaming probably never touched 80. I want to know how you are achieveing 80 degrees idle tbh, if your case has great airflow and the cooler on the gpu is not blocked with dust then I can only assume there is poor contact between the cooler and the gpu. You should have RMA'd the card when it was still in warranty, regardless of whether it was crashing.
Having a card at 80 degrees constantly whether 1,2 or 3 years could cause many problems.
