Is my Corsair H100i v2 dying?

[ProfDigity]

Hello TomsHardware Community!

I have a question about my Corsair H100i v2 CPU water cooler. I have had this cooler installed for about 3 years now and for the first 2.5 years my temps on my CPU almost never got above 65c and my idle temps were around 35c. Now, over the last 6 months, I have noticed the CPU getting as high as 85c with idle temps around 40c. This is all while playing games such as Battlefield 1, GTA V, PUBG. I know these games can be CPU heavy, but I see no reason why my CPU should be getting that hot under load. I thought it may be the pump, but it appears to be working and my CPU isn't overheating. Is it possible that this is a sign that the pump is dying? Should I reapply new thermal paste? I need help!

Note: I ran the intel burn test. On standard my temps get to about 75c. On high (just above standard) they get to 90c in a matter of seconds!

System Build:
CPU: i5-4670k (not overclocked...yet)
MB: ASRock Z87 Extreme 4
GPU: MSI GTX 760 HAWK (not overclocked...yet)
RAM: 16gb G. Skill Ripjaws 1866
PSU: XFX 750 watt Gold certified
Case: NZXT Phantom Full tower
Fans: 120mm Front, 2x120mm side, 240mm side, 2x120mm top radiator, 120mm rear

 

[t53186]

You could try cleaning and applying thermal paste, cleaning the radiator and case interior. Couple things that may contribute to the problem, less airflow and higher ambient room temperature. Both can reduce the effectiveness of the cooler

 

[ProfDigity]

You could try cleaning and applying thermal paste, cleaning the radiator and case interior. Couple things that may contribute to the problem, less airflow and higher ambient room temperature. Both can reduce the effectiveness of the cooler

Thanks for the reply! I should have mentioned I cleaned the case out a couple days ago to see if it would help and it made no difference. However, I will be receiving some thermal paste today. I will try to reapply and update this if it makes a difference. I just don't understand why it would slowly start to perform worse and worse. Most forums I have seen refer to a complete failure of the pump or problems with it soon after installing. My problem doesn't meet either of those criteria.