I hope it's ok for me to resurrect this thread. I've replaced the battery in a 2017 MacBook Pro 15, model A1707, and post-replacement the fans are running 100% and the CPU is being consumed approx 500% by kernel_task. This thread prompted me to download TG Pro, and I have used it to diagnose a possible hard drive temp sensor issue.
Is the hard drive temp sensor servicable? Could this simply be a ribbon cable issue?