loose sensor cause this?

[SDSGSX]

okay....driving home on the highway I95 my temperature in the gauge cluster started going down.....it wa about 1/4 the way up on avg. When i got into town and took a turn a few min later it was normal. Anywayz i went to look at my temp sensor the small one under the radaitor cap and i noticed that the plug part of it slides almost all the way off and back on with no effort. Is this normal? is there supposed to be a metal clip or something holding this on? I thought it may be thermostat but searching the msg boards i found out a few people had this problem. I think i may have hit it putting my upper upper ic pipe on. Thanks for the help guys.....

 

[Defiant]

Take some needle-nose pliers, or a very small screwdriver, and gently bend the contact inside the connector so that it will have a bit more friction.