cpu temp rising

A few days ago I thought to check the temps using core temp monitor and noticed that the cpu temps kept rising. After about 30-45 minutes it would reach 80-90's and still going up, so I stopped using the pc. Next time I went on pc and the temp went back down but started rising again.

My cpu is i5-4670k with corsair H60 cooling. I changed round the fan to see if that would help. It didn't matter if fan was pulling air into cpu or taking hot air out of cpu, the temp would keep on rising. It made no difference what I was doing on the computer - could be browsing the web, just working on the desktop or even in the BIOS setup screen, the temp would go up starting from about 40 when pc is switched on and rising to 90's. When it got that high I would switch off pc as I didn't like the idea of cpu reaching 100.

I even turned the H60 radiator upside down so the tubes would be at the top and go down to the cpu - no difference. The system temp is not a problem, it is around 40 and is cooled by 2 fans in the front.

I bought the H60 as part of a motherboard bundle last year in June and the motherboard is gigabyte z87m-d3h board.

What else can I be doing to keep cpu temp from rising all the time?

You can try reseating the heat-sink, applying fresh thermal paste.

Do you get the same temps with other programs? Say, HWinfo? How does it show in BIOS?

Do you have any OC going on?

I did think about reseating the heatsink but decided to leave that till the last after trying everything else out.
Haven't used other monitoring software but gigabyte motherboard has an utility "gigabyte app center" that shows the same temps as on the core temp monitor. BIOS also shows the same temps as everything else so we know it is a problem.

Interesting article about the Intel Application methods - will refer to it when reseating the heatsink.

Is it possible that tubing from radiator to heatsink isn't right?

Also I haven't done any overclocking.

There are no fluids/stains on the bottom of my case. I think I will probably do the reseating after I have explored all other possibilies.

Thanks everyone.