i have an 89 RS 305 TBI and i have an ongoing problem with the temp gauge. it seems like no matter what i change the gauge still climbs and pegs eventhough the car isnt running hot. i have changed out the sensors on each side of the block, even the one between the #6 and #8 cylinders. i have also installed a new OEM gauge. the only thing i havnt changed is the sensor that is on the top of the intake. anyone have any ideas? anything else it could be other than the sensor on the intake?

 

get a mechanical gauge, i had the same prob, replaced stock gauge replaced sender etc, same thing, finally got a mechanical gauge now it never goes over 210, and thats in 110 temps

 

Does it peg fast, or does it take some time. If it happens fast look at the drivers side guage sender, it has a single green wire. make sure it isn't burnt and touching the exhaust manifold. That will make it peg. Are you sure you changed the guage sender, and put in the correct one.

 

it doesnt peg fast, it is strange cause sometimes it will and other times it wont. but i did check the driver's side sender and i got the right one (from dealership) and i checked the wire along as far as i could trace it and there are no worn spots. however, there was a spot where it looked like someone had spliced in another section of wire (which i dont understand cause there was more than enough) so i took that off and put a new connector on. but im still getting the same hot readings on the gauge.

 

how do u know that the car is running hot? have you hooked an aftermarket gauge up to it?

 

i have checked the system with 2 different thermal guns and i get consistant readings in the range which the mechanic said it should be running. 225 is the number i remember but im not sure at what point of the system it was measured (thermo housing, top rad hose bottom, etc)