i have a 2000 tacoma prerunner v6, and here recently the needle on the temp gauge moved slightly above the middle where it normally sits.the truck is still running fine,but should I be worried? what might be causing this?

 

Please describe the driving conditions you are seeing this change under.

Towing, idling, freeway driving, city driving, all of the above...what?

 

all of the above.

 

1. Inspect the area of the water pump. Check for leaks.

2. Test or replace your radiator cap

3. After running the vehicle to "normal" operating temp, shut it down and immediately try to spin the fan. It should not spin easily.

Any recent changes/mods/maintenance work on the vehicle?

 

no, totally stock.

 

Definitely check the water pump. Mine started to leak causing the temperature to creep up slightly. Luckily I caught it and I had it replaced ASAP at the dealer.

 

And you should still be under the 5 year 60K powertrain warranty (assuming your mileage is below 60)