Radiator well there is a hole on the top right side of the radiator. it may have had a sensor or a plug of some kind. i pluged it up my self but i dont want it to hurt the car... like i said it is on the top right hand side, but it is not the reserve tank line. that is still on. please help

the dash board Temp. sensore is located in radiator near bottom or sides just search around the radiator for rlectrical wire check the wire is pluged into sensor probably check the wire is good and is connecting the signal then check the sensor it selfe by measuring its output resistance when its cold then but in in a dish full of boilng water take the reading again it should read resistance less than the cols state otherwise the sensor needs to be replaced (it could give you no reading due to internal open circit corrupted sensor or it can give u no resistance change or a ver slight change while it should gives a bog diffrances
unplug it test it
replace it
good luck sir

check trance fluid level. Go check the trance radiator for a hole small hole about the size of a penny or smaller if nothing there follow the steel line's from radiator to the transmission.

If the holes are in the side tank,they are for the automatic trans. linesIf you have a 5 speed that is not needed and will be no problem using it.

That is your radiator plug. You take it out to drain the radiator. You just take it out and put another one in. Is your radiator fans working? It may be the radiator itself. Plus, it may be a coolant temp sensor. If it is a small leak, with full coolant, it wouldn't overheat quickly. Make sure the fans kick on. Check radiator.

under the driver side rad core suport there is a small access hole you can get a flat bladed scewdriver thru,if you look between the core support you can see the plug its usually orange right under the radiator its not easy to get out or see if you dont know the product, i hope this helps.

Most likely the heat sensor.
Ensure you replace the gauge sensor with the correct type to suit your gauge.
(dont confused it with the overtemp alarm switch sensor).
Check you've got the right sensor by shorting it out to frame/ground and observing the gauge movement.

The Coolant temp Sensor is located right under the top radiator hose (on the engine side), with a little black connector!, You might have to remove th etop hose to get to it with a deep socket and extension!.
Also Dont Forget to blled the coolant system by the bleeder valve uptop right near/above the coolant sensor!.(10MM Mini socket w/ extension IIRC!)

You can actually do it from the top if it is similar to a 2001 Elantra??? On your right center of the tranny, there should be two big bolts I believe a 17mm one on the bottom left the other top right of the other. The bottom left is the drain plug the top right is where you fill it. If you want to make things easier you can remove the air cleaner and the air cleaner housing then unscrew the sensor on top of the tranny you can poor it in from the top. You will need to then unscrew the fill hole (Top right bolt) Pour the lube in to the hole where you had taken out the sensor until it pours out of the fill hole. Sounds like more work but by doing this you will avoid making a mess trying to fit the squeeze bottle into the tiny hole. Hope this makes Sense????

your radiator could be pluged up internally especially if you havent bought this new. alot of people will dump in a radiator leak stoper if the radiator has a small leak and that is not the right thing to do because the stuff can plug up a lot more than the hole.if you take the radiator out and know of a radiator shop they will flow test your radiator and let you know if it is pluged up internally or not i hope this helps you and please rate my solution.
thank you

well you dont actully have to drain the the block its self. There should be a drain on the radiator on either the right or left bottom side of the radiator.