I want to start off by saying this site has shown up in more Google searches in the last year then any other site for all my issues I have been troubleshooting. You guys know your stuff!

I picked up a 63 coupe DeVille about a year ago and have put a fair amount of work into it. Got about 100 miles on it this last summer, you need to start somewhere.

Currently I'm working on the temperature gage. I'm trying to figure out where the needle is supposed to sit under normal operating temps. The shop manual doesn't state where it should be and the closest thing I found was a post on this site a couple years ago where someone stated theirs is at about halfway on the gage at about 220 degrees. The highest I've ever seen mine go is about a quarter of the way up. I know comparing this to modern vehicle is wrong, but halfway is where I'm used to seeing them. Is a quarter of the way up the gage normal or should I start troubleshooting things? Thanks in advance for any and all information.


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Thank you everyone for the responses. I don't plan on driving the car in the winter (they salt the hell out of the roads up here) so I will go with the 180 thermostat and see what I get.

Don't forget the black holes.....

As always i thank you for your thoughts on any and all things 63-64 Cadillac
I have never seen a 175 degree thermostste in my lifetime so that does surprise me that it was stock
There is so much to learn about these two year Cadillacs and there systems it enough to keep a lot of people here very busy


Tony, There is one on eBay you can see by Clicking Here. It would make a mighty fine Christmas present for your 63/64 Cadillac Webmaster!

Poor ol Tony, he'll never buy a 175 degree thermostat even as a gift.

It's not that he can't afford it, doesn't wanna do it or anything except maybe his pride. LOL.

C'mon Tony, bung a 175 in the ragtop..... I F*^#ing dare ya..... PMSL

Mine also runs about a quarter way with a 190 thermstat

i do like the 195 in my 429 best of all for the way the engine performs Over the 180 and 160 And i am sticking to it
I had each termistate in the car for a number of years
I did not pull this out of the air or a black hole gentelmen

The 180 is a bit over the stock 175 that was an eye opener and real surprise to me

One thing i do not understand about this is if your 180 opens at 180-183 degrees and then add i5 to 20 degrees to full open the car SB running at 195- 200 degrees for a limited time as all settles into running back at 180
The higher 195-200 degrees the engine is producing can only be for a --very limited amount of time --until that coolant first moves in and thru the rad
So those start up temps become irrelevant as for all practical purposes you are running at a constant 180 degrees with that calibration thermostat />
The stant thermostst info indicated you would be running 15-20 degrees hotter but said nothing about for how long giving the impression the running temp WB higher than the 180 calibration which is not the case
After all you are running the 180 so you run at 180


Tony. I run a 180 degree thermostat. That is the temperature the thermostat starts to open. Per info on Stant site it is fully open about 15 to 20 degrees above stated rating.  That means it should be fully open allowing water flow at 195 to 200 degrees.  My car warmed up gives a temp rating about 197 degrees via the digital IR Temp Gun. That is exactly where it should be.  
The only thing to add, is I think you should consider a digital temp gage if you do not have one.  You cannot guess or assume a specific temperature based on an unmarked temp gage.  Finally, the engine is not going to run at 180 degrees if running a 180 degree thermostat. Again, that is the temp the thermostat starts to open. The engine is going to run closer to the fully open temp range. Of course an engine can run MUCH higher than even a thermostat temperature "full open temperature" from many other issues such as timing, low coolant, worn engine, clogged channels, etc.

I have to go rest now !!
I wrote the word --THERMOSTAT --- more times than i ever wanted to in this life time


Tony. You better get up and get to bidding on that 175 degree thermostat. 

Pmsl Tony

You are a super great guy and the last word here--for me -- on the subject of our cars ----but on my Christmas list ?




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