ok, this is really weird... when the car is running warmed up the temp gauge is perfrect and where it should be. but when you rev past 3k it goes all the way down pass the min. mark then when you let off it it goes back to normal. this ever happen to anyone before? i searched but didnt find any of these cases. Thanks Shaun

 

I know what it probably is. Bad ground. I've had 2 temp gauges that didn't work right because of its absence or improper connection.

 

do you have any heat coming from the vents if you turn the fan on? (if you still have your heater core.. and this isnt a full drag car) if you turn the fan on and it blows cold you might have some air pockets in the cooling system
or you might have a faulty thermostat.. keep an eye on your coolant level and check some stuff out get the car warmed up and crack open the bleeder valve on the head to try and get some air out. good luck

-Larry

 

or what he said

 

i think the thermo is prob fine, i get hot air.. except for one vent(hah) but it seems to be something electrical because once the rpms drop the temp goes back to normal

 

ttt

 

had the same problem in crx with the a6 engine. i never figured it out . but when i swapped in a b sereis it didnt do it anymore. so id figure its a bad ground. or he connector is not fully on the coolant temp sensor in the head . thats the one for the gauge. or just the temp sensor is bad. mine would fine and dandy till you take it over 3k then it would just drop to cold.

 

well at least its not rising.i wouldnt even worry about it.