when i'm at idle my temp gauge is at the normal position but when i start to drive the car hard or take it up high in the rpm's the gauge goes cold and usually stays that way until i just let my car idle then it returns to its normal position. why is this? i was doing a search some say its the water pump and or could it be a bad thermostat or bad coolant temp switch? or maybe its a loose ground or dirty connection? well just let me know what ya guys think. ok thanks

 

for me, it was a loose wire by the sensor which is under the distributor...download the online helms and check it out...should tell you how to check it with a multimeter...

 

my car does the same exact thing I guess.

I have no termostat.

 

yeah he's right i had the same problem. its the wire located under the distributor. mine was covered in oil from a leaking seal on the distrib. so either its dirty or it just came out. the wire is a female clip, single, and plugs into a nipple on the head.
haha that sounded kinda off.