Temp Gauge acting funny - Possible Thermostat Problem?

[atoyota4x4]

I just purchased a 2000 Intrigue with about 67K on it. It just so happens thats I drove it to work this morning instead of my wife. Anyway, I noticed the temp gauge every once in a while slowly climb above the half way and almost up to the tick before its goes all the way to hot. I guess the 3/4 tick is what I'm refering to. Anyway, about the time it gets to that its slowly drops back to half then stays just below the half tick. Then it might sit there for a few minutes to 20 minutes then it slowly will creep up to half or slightly above half them drop back down. Most of the time on the interstate it stayed in its normal position just under the half mark. It seems to have this fluctuation when driving around town or 60mph or below. I'm thinking its a possible thermostat thats sticking every now and then. Anyone want to give me there thoughts? Surley this is not normal.

Also, on another note, and I don't think its related, the Service Engine Soon light came on about 20 minitues after leaving this morning while on the interstate. Probably a stupis emission thing. I checked the gas cap and it seem to be on and tight. Guess I will go and get the code read at a Autozone or somewhere.

I will keep you guys posted on the light situation and I think I may change the themostat this weekend unless I hear from someone on here saying thats not the problem.

Thanks

Matt

[janellegargarita]

I had the same problem recently. I took it to the shop and they told me that I have a crack in the engine and I need to replace it at the cost of $6400. I found another engine but My car is set up for California Select Component and the one I bought is Federal Emission.

[intrigue2001]

Check your coolent level if it is low you will get the same results, make sure you use the dex cool which is orange in color and not the green. the cap has the color of the coolent you need.

[BLKIntrigue_98]

Before tossing the engine, try a new water pump, it fixed my problem of the temp going to 3/4 and back to half intermittantly