Overheating still

A friend drove my truck and my truck started overheating and he drove until it froze the tension-er well we changed the tension-er and then we found out that the heater value was broke so we changed it. Well we drove it to the store and back and the gauge said it was overheating again, but we cannot find a leak or and there is no smoke anywhere. I tried to turn on the heat but it seems like it did not help there is under the hood exact explanation. Then when I was pulling into my driveway the truck cut off we let it sit for a minute and it started right back up so I could pull it up and turned it off.