Better not be the hydraulic cooling fan

[pektel]

So, this has been bugging me. Last week, the engine was running hot. Not to overheating, but about 3/4 of the way up the guage. It hapened twice within a coule days, and it's been fine ever since. Now, I'm thinking that the tstat maybe stuck for a short period of time, then just popped open a little late. My other thought is that the hydraulic cooling fan motor may be starting to go. It was hard to tell because I had the music up, but I thought I could hear that humming noise like the fan really trying to work.

Any ideas on what could be the culprit?

 

[gcwimmer]

If the fan is working then look at the thermostat sticking.

 

[pektel]

See, the problem I have with only believeing it's the tstat is because it was at the 3/4 temp for over a minute. I would think that a sticking tstat would spike, then immediately drop once it opens.

Sorry I forgot to add that to the op.