Wacky wifi/kernel_task issue

[HolophonerVirtuoso]

I upgraded to Mojave a few weeks ago and it was fine for a bit. Now I'm having a big issue with wifi. After a few minutes of use, kernel_task will random shoot up past 100% CPU (sometimes nearing 200%), majorly lag the whole system, and disconnect from wifi. When I click to reconnect to wifi I get the spinning wheel and it sometimes takes minutes for anything to become responsive again. When it settles down finder won't be able to see any wifi networks for many minutes and the whole thing starts over again. Interestingly, the system also gets very laggy when I click around network options in system preferences.

I have renewed DHCP lease, reset SMC and PRAM, and am now at my wits end. Any thoughts before I need to resort to a clean install (which I'm not thrilled about doing?)

 

[Honza1]

Before clean install, install current version of MacOS over the existing installation. It will reinstall and reconfigure everything leaving your data and apps in place. This has fixed few weird issues for me over years. Just download current MacOS installer from Apple app store and run it. It may - or may not - help. But is less destructive and annoying than clean install.

 

[HolophonerVirtuoso]

Something to add. The wifi isn't even accessible in recovery mode. When I click to connect, I get the spinning wheel, every locks up for a bit and repeat.