Chosen Solution
I noticed my MBP had been really slow lately sometimes, the problem got worse and worse overtime. Kernal_Task has been using up the CPU even without any loads. I thought my MBP was dirty, so I opened it up and found the battery expanded very badly, although it only had 20 cycles over 3 years of usage. Trackpad was very stubborn and I had been wondering why, the battery crooked the frame.
I went ahead and bought a replacement battery and had it replaced. The problem is still there.
I noticed when this happens, CPU Temp from Core 1 - 4 are disappeared, as well as CPU PECI and Intel GPU.
As soon as the temp readings come back, kernal_task goes back to normal.
Did the expanded battery cause damage to the logic board ?
Is a repair even worth looking into?
Update (10/15/2016)
I’ve tried resetting the SMC several times, still the same result.
I just took it apart, will re-apply thermal grease tomorrow and see what happens.
with the new 2016 MBP refresh coming around the corner, i just want this MBP last a little longer.
Update (10/16/2016)
Here are the screenshots of the temperature readings.
It does sound like your systems logic board is in trouble here. Did you spill something into it or sit it down on a wet surface? I would install this app so you can better monitor whats happening here with the thermal sensors: TG Pro for less than $20 US its worth it! Post a screenshot of the main screen so we can see what its’ telling you. In the meantime I would strongly recommend you make a good backup if you haven’t yet as well as prepping up a bootable USB thumb drive with the OS installer copied to it so you have a lifeline just in case.
I have had issues before with the fan/temperature before, try resetting the SMC: Shut down the computer.Plug in the power adapter.On the built-in keyboard, press the Shift, Control, and Option keys on the left side and the power button, all at the same time.Release all three keys at the same time.Turn on the computer.
