Grunt Noise when First Engaging Clutch

Starchecker

I have searched far and wide for a few years and haven't heard of anyone with this issue or what it could even be.

Typically, it only happens in the morning after the car has been sitting for hours or even a couple days, but when I first start to engage the clutch by letting up on the clutch pedal, I get a little grunt noise, not immediately as the clutch engages, but very early on in the engagement travel. It's very brief and doesn't do it again for the rest of the day, even after sitting for several hours.

It's usually in the cold time of year(I live in Colorado) and it's not every time.

Nissan has replaced the transmission 3 times when it was under warranty, but it never really seems to fix the issue, as it will just reappear again in a few months.

It does seem to manifest more frequently, if I don't take it in for the transmission to be replaced, but I find it very hard to believe that I got FOUR bad transmissions in a row(the one that came with the car and the three replacements)

It's doing it again, now that I am out of warranty, but again, infrequently. It seemed to get better when I let the car idle for at least a few seconds before just backing out immediately after starting.

What changed a few nights ago, I had driven it for over an hour to a party, but when I went to leave, it not only did it while I was initially backing out, but when I went forward in first gear and then, when the clutch pedal was fully depressed it seemed to make that noise a little as well. First time for that. Plus, I got the cement mixer sound, that happens with Z's sometimes, when the clutch pedal is released and you have it in neutral. That made me wonder if the clutch wasn't fully disengaged when the pedal was fully depressed.

I'd attach a recording, but it's stopped doing it again. If I had to describe it, I would compare it to the sound of a dry bearing surface, that's supposed to be lubricated, and when you initially turn the rod that's inside the bearing you might get a little grunt noise out of it as the static friction breaks loose.

At this point it doesn't make sense to take it into the shop as you typically only get one chance to hear it per day and it's not even every day that it does it. It's honestly been doing it infrequently for the last two years (outside of warranty) I figured if whatever is wrong gets bad enough, eventually it will be easier to diagnose. That night at the party was the worst it has ever been, introducing a few new aspects of the issue. I figured for sure I'd have to take it into the shop, but once again, it's stopped doing it.

There are no other transmission issues. Not difficult getting into any gear, no clutch squealing noise, not slippage when in gear. I've looked up every symptom of manual transmission issues and can't find anything that describes my problem.