Hey all, my car had some issues today..so wife was in car (car idling) while i was in store and she tells me she shut off car because it was idling funny. (Low idle) almost like it was going to stall. I restarted and sure enough low idle like it was going to stall out. After a few minutes it seemed normal so I drove off again. At drive thru to get my kid food and I noticed temp gauge was higher than normal. Checked under hood and only thing I noticed was coolant overflow was higher than usual...usually its halfway between low and full and it was showing just about at full line. No apparent leaks or anything and no codes thrown (no check engine light) as didnt have my scanner to check for codes. Had it towed to mechanics. Tried to read up a bit wondering what it could be (was thinking head gasket) so checked oil and it looked fine on dipstick, not muddy or abnormal. From what Ive researched Im thinking coolant temp sensor maybe but im not certain. Just curious if anyone has experienced this or if anyone has any ideas on what it could be. Mechanic is only in on Monday so im just curious what it might be. 155k miles. 1zzfe engine. Thoughts appreciated