Chosen Solution
I have an old white mid-2010 MacBook that can get uncomfortably hot, e.g., while sitting on my lap. I upgraded it a couple years ago to have a SSD. And just replaced the battery. (Both done with ifixit community help, thank you!) I thought a new battery would solve the overheating problem. But it has not. Anyone familiar with this issue?
Examine the crimped end of the heat sink and look for any oily type of residue around it. It you find it your heat sink may have leaked and no longer dissipates heat the way it should. MacBook Unibody Model A1342 Heat Sink Replacement
If you are in the northern emisphere it’s likely that the few degrees temperatures increase of the last few weeks have had an impact on heat dissipation..the hotter it gets the more heatsink and fan have troubles to get rid of surplus heat. You could try at least to remove the fan and clean both heatsink and fan from dust. Since it’s a 7/8 years old machine it would probably be necessary to remove the logic board and replace the thermal paste with a fresh one if you feel comfortable in such task..or have someone do it for you sooner or later :)
sounds like you need to replace the thermal paste which cools down the cpu and make sure to clean your fans/vents while you’re at it :)
