Mac Fan Control

I have had for some time been experiencing problems with he inbuilt Fan Control on all my Macs, from 2008 iMac, various generations of Mini and unibody MBP. Seems to correspond with upgrades to OS and especially post big cat OS. First noticed way processor speed slowed right down, then later got so hot that crystals in heat transfer mate turn to a liquid that flowed out onto desk and alerting me to it.

Loaded various 3rd party monitors and found at times getting up to 88 Centigrade and automatic system hadn't raised fan speed. Now have manual control system, but as this is a fundamental process I am concern that its not work. I am an electronics engineer by professional and understand the relationship between MTBF (mean time between failure) and exposure to elevated temperatures. if left too long will significantly short life of components, processor, hard drive and at those temperatures affect reliability of solder on PCBs.

I have made several enquires to Apple Support, but not living close to an Apple Store (resellers are hopeless, advise not using them) no convent to take machines in which is their main advice.

My questions are:

1) Anyone else experienced similar problems?

2) Is there a third party monitor that will log temperatures to a file and is easy to use?

3) Is there a third party monitor that still allows automatic control to operate and override manual settings?

4) Is there a third party monitor that flashes the screen, bleeps or gives some significant alarm when a trigger temperature is exceeded?

Cheers,

Q.