CPU utilization low, system hot, fans loud

I forgot about that. Had to do it a couple years ago. Will give it a try.

I have tried the SMC reset twice. No change at all -- rather everything seems fine for 10 minutes, then it reverts to a crappy state again: 1% CPU utilization, the fan is blowing hard. The back of the iMac is hot. So the SMC reset does not seem like the solution.

When I try to post the report it says that there are invalid characters and the forum refuses to accept it. The litte information icons looked suspect, I deletedt them all but that made no difference.

let's try it this way

https://gist.github.com/eezis/8a84830505ebf2384c88a8dd9004afaf

No, sir.

So I did the "Option D" on the restart and the hardware test stopped 37 seconds into the RAM test. I removed the original 4GB modules that came with the system, leaving 16GB instead of 24GB. So far so good. New temps on the left, original temps on the right.

Temperatures increased after an hour. System was under very light usage -- Chrome with 8 tabs, imessage, Spotify were running but I was working on a second system. CPU was 1% - 3% or less. Closer to 1% most of the time. The fan is audible but not terrible like it was earlier.

I find it hard to believe that a nearly idle system should be this hot by design. Not sure what's normal for power supply readings.

"You appear to to be manually overriding the fan speeds . . . " Negative. That has never happened. These are my development systems. I don't play with them. The HDD fan and temp should be low, it's an SSD.

The ambient temperature is not 38°C, more like 21. Perhaps that application is measuring the temperature of the case or something. The depicted measurements are from TG Pro, which I downloaded to investigate this problem. I don't even keep it running. If there is a more accurate application or better yet, a built in app that will provide better readings I welcome the suggestion.

I re-ran the Hardware Test. No problems found. In fact, I think there was no problem the first time. I now think that I mistakenly stopped the test early because I was expecting more from the interface . . . like progress updates. The system does seem to run "normally" after the test, so it seems pretty good again, but now I wonder if it will heat up again over the next hour or two.

In response to your earlier question . . . . I installed the SSD, carefully cleaned all the dust out the system, etc. Broke the LCD connector when putting it back together, that cable was replaced by a certified repair shop. Again, this system has been running for nine months without issue until recently -- if there was a misplaced airflow deflector it suspect it would have surfaced earlier. Dust is not an issue. Accumulated dust was removed when the SSD went in and I run an air purifier next to my systems as well.

I didn't know it was, probably pilot error from when I first installed the application and was checking it out. I opened the app again and I reset it to system. But the app has not been running. It was only installed to investigate this problem. I start it, take the screenshot, close it. And I will delete it as soon as I don't need it. It doesn't auto start and is not part of the normal environment.