I installed a new aftermarket temp gauge in my 455 powered 64, when I installed it I moved my temp gauge sending unit from its location on the front of the engine near the water neck to the hole in the intake at the passengerside rear, I have noticed the the gauge reads hotter at idle than the old gauge and shows more dramitic shifts in temps from cruising speeds (170 deg) to idle situaions (210 deg), I guess it is possible for the gauge read differently than the old one but I am curious, does anyone know if the rear location reads hotter that the front location or had similar experiences?

 

I installed mine on the drivers side rear and with the 180 degree stat it reads 180 when at idle and just under 180 when driving. Reading remains steady. Might be a bad sending unit. My gauge is a mech unit.

 

The temp gauge sender needs to be in flowing coolant. If you screwed it into the boss at the back of the intake where the heater valve usually goes, that's a "dead end" for coolant and is unlikely to provide an accurate reading. In addition, this is a good place for air to be trapped, again making the reading inaccurate. The sender really wants to be in the crossover at the front of the intake.

 

I have my aftermarket sending unit in the front right in the intake(1975 455) and mine is running around 210 on hot days is this safe. I have not been running it on hot days cuz I'm afraid I will cook the bearings. Put in a 160 degree thermostat and new cap for the radiator still no change. Please help I think I may need a new radiator. Also it doesn't have the fitting on water pump for the heater core cuz It is in a 65 Olds Jetstar so I just plugged the back left hole on the intake that would go the the heater core Also how would I check the clutch fan it seems to be working fcine as it spins faster azs I rev the motor. Also I have running it would the hood off would that make a difference?Thanks guys

 

Seemed to be a bad clutch fan will see tommarrow when it is 80 degrees. I had an extra fan laying around I firgured this would be a cheap fix will see what happens. Had it running tonight 66 degrees here and it would not top 170 tomorrow may be a different story

 

Wasn't the clutch fan today when I drove it it ran 205 and kept creeping up. Guess I might have to put a radiator in it. Unless you guys think it may be the water pump as it looks original. Also it does not have the fitting for the heater core (which I need) right now I have the back left hole on intake plugged the one that goes to the heater core. Could not going through the heater core cuz it to run hot? I think I'm going to go ahead and change the pump first as I have a good one laying around that way I can have heat 2 :-P Also I'm running Valvoline 5W - 30 Oil could that be causing it? I just wanted to run a thinner oil for the first month or so as the motor sat for a year or 2 before I put it in. I would like to obtain a constant 180 degrees

 

Got a radiator coming should be here friday seems that might be it for $140 brand new seems good to me:-P

 

I believe the radiator was the problem I installed a new one today and drove a steady 3000 RPM with the temp never going over 180 degrees of a hot day here (eighty some). I also let it sit and idle about 20 minutes after the drive stayed a steady 172 degrees. That's with a 160 degree thermostat. I wish they made relplacement parts that actually fit the 65 Jetstar 1 seems like I have to alter something everytime. The top and bottom drives side brackets had to be altered as the old radiator was alot skinnier on that side hey can't complain $160 4 core shipped to the house