Macbook Pro 8.2 2015 kernel task 100% and very very slow

[smic717394]

Hi,

I need a bit of help. I have a Macbook pro end 2011 8.2. I bought it of a customer cheap because it has a bulged battery. I replaced the battery and upgraded the ram 2x8GB total 16GB, and replaced the HDD with a SSD. What happens with this laptop is very strange and I don't know where to begin. The laptop doesn't panic, tha fans run normal even when the kernel is 100%. If I reset the SMS, will run normal for about 30 to 1 hour then the kernel_task goes to 95% and the laptop become unusable. If I reset the sms agail will run again normally for some time. I thought is the battery, so I tried to use it without the battery, same works for some time, then again, I tried the original drive, same, I tried to put back the original ram, same.

I scanned the ram with mem86, 4 pases and fine, I runned ASD few times and it passes every time. I installed Ventura and Big Sur OLP with the same result. I'm now installing high sierra, and aduring the update, on the first restart I think it was updating the firmware, it was beeping I think 4 short and 3 long or something like this, the led would flash 5 time ( 3 times) then it would start with a larger font, it restarted after the bar loaded, and now is starting again fine. So I´m going to try to install high sierra, but I´m out of ideas.

[mon2]

Is the trackpad attached? Disconnect it. Does the fan enter high speed? There are sensors inside of the trackpad that may have been impacted by the bulging battery.

Test with an internet boot / external drive with a clean OS boot. Is it stable with this mode of booting?

[smic717394]

you mean to install from Internet recivery on a external USB drive instead of the internal drive?

[kevingill]

These are usually symptoms of a corrupt BOOT ROM. You might want to flash it with a cleaned ROM and try again.

[smic717394]

I think the problem might be the battery I bought on Aliexpress. Yesterday I removed the battery and installed clean again High Sierra on a ssd, then updated, and I left it on for at least 6 hours, no problem whatsoever in this time. After All this time, just to verify, I turned off the laptop and reconnect the battery. Apparently was working find, but on the first boot after I connected the battery I noticed something is wrong. It took double the time to load, and I noticed the ambient light sensor isn't working anymore, where before was working. I tried to boot, with the camera connector disconnected, thinking maybe the ambient light has a problem, and this communication I think its handle via i2c, but the same. I disconnected the battery, reset the pram and smc but the ambient light was still no working. I reconnected the original hdd and boot, with the old drive the ambient light was working fine.

I just reinstall again the OS, I think I will use it few days without the battery just to have a benchmark point, after I will connect the battery. If after the laptop start behaving poorly, I think it's clear the problem is with the battery