Hello, my thermostat is stuck open on my 84 vette. i need to pick up a new one before the store closes at 6pm. do i get a 160 or a 195 degree thermostat?

Also, i am unsure how to install it. is it easy? does anyone have any diagrams that can help me with this? -thanks
-Dan

 

hi, and welcome!

the t-stat is rather easy... follow the top radator hose... and there you go! it is attached to the intake manifold... at the front of the motor.

ok... I think you can install the 160 and get good benifit. you may also need to get a lower temp switch... JonM is the local guru on 84s...

 

you would be better off getting the 160 stat instead of a 195. I'm unsure of the Crossfire setup but i would have to drain (at least partially) the radiator and the thermostat is directly under my Throttle on the manifold at the front of the engine. DONT get a Haynes manual, they dont help, and the one i have here has about two sentences on 84's-so its even less of a help.

 

You will thank yourself in the wintertime if you use a 195 stat. If you went to a 160, the temp would still be higher than 160 degrees at idle because your fan would not be onyet, so with stock fan-on temps, a 160 stat would just shock the cooling system more than it needs to.

The LT1 cooling system is much better at reducing thermal spikes in the engine than the 84-91 cooling system. Just go with stock unless you change the temps.

You will not need to drain coolant unless there is way too much in your system. The upper radiator hose should be dry if the system is cooled. Any coolant that does spill out will likely be very minimal and a shop cloth around the stat housing will take care of that.

The 2 bolts are likely 9/16's and are likely close to being seized if the stat hasn't been changed for a while. If you are lucky enough for them to brake loose, after a 1/4 of a turn to loosen, turn them CW again to tighten slightly. Then go a half turn loosen, 1/4 tighten, and do this until the bolts are all the way out. This will prevent thread rolling and then you won't have to tap the threads like I did. It would be a good idea to chase the threads with a bottoming tap or a clean bolt.

I never use a gasket because I have the stat out about every 3 months. I have used permatex blue, ultra blue, ultra copper, and the 'right stuff' gasket in a cheeze-whiz type can. All work without leaks. It would also be good to put anti-sieze on the threads when you reinstall the bolts so you won't have a problem with siezing down the road.

The spring goes down and the pointed end goes up.

Good luck, -Matt-