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The thermostat on a 1997 Cadillac is on the rear of the engine (driver's side). Follow the upper radiator hose from the top right (passenger side) across the front of the engine over the fans, then back and down to the thermostat housing.

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-- Click Here for CaddyInfo page on "How To" Read Your OBD Codes
-- Click Here for my personal page to download my OBD code list as an Excel file, plus other Cadillac data
-- See my CaddyInfo car blogs: 2011 CTS-V, 1997 ETC
Yes, I was Jims_97_ETC before I changed cars.

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The thermostat on a 1997 Cadillac is on the rear of the engine (driver's side). Follow the upper radiator hose from the top right (passenger side) across the front of the engine over the fans, then back and down to the thermostat housing.

does any one have a pic? im sorry i cant find it

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The stat is in this photo in the bottom center, the circle (stat) within the bigger circle (water pump cover).

WaterPumpandRadiator022-1.jpg

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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The stat is in this photo in the bottom center, the circle (stat) within the bigger circle (water pump cover).

WaterPumpandRadiator022-1.jpg

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Any advice on changing the thermostat? Pitfall's?~~~Thank's

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Any advice on changing the thermostat? Pitfall's?~~~Thank's

You may need to purchase a new water pump cover it has been redesigned and the new seal does not fit the old cover.

You need a 1/4" ratchet handle or breaker bar to release the water pump tensioner

Dont forget to buy the thermostat seal, I dont believe it comes with the stat

Clean the bolt with a hole in it while you are in the area

Dont flush the engine with water it throws off the coolant concentration and its difficult to get back to 50/50

Look at the by-pas hose to see if its ok and check clamp tightness

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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Thank you~~~Coolant tab's~~~I've read yes~~6~~none ~~~3~~~small~~~and bigger?~~~Can I ask your advice on that as well~~~thank's

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Any advice on changing the thermostat? Pitfall's?~~~Thank's

You may need to purchase a new water pump cover it has been redesigned and the new seal does not fit the old cover.

You need a 1/4" ratchet handle or breaker bar to release the water pump tensioner

Dont forget to buy the thermostat seal, I dont believe it comes with the stat

Clean the bolt with a hole in it while you are in the area

Dont flush the engine with water it throws off the coolant concentration and its difficult to get back to 50/50

Look at the by-pas hose to see if its ok and check clamp tightness

ur the man thanks alot homie.i will try and change it tomorrow good lookin on the pics and info

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Thank you~~~Coolant tab's~~~I've read yes~~6~~none ~~~3~~~small~~~and bigger?~~~Can I ask your advice on that as well~~~thank's

If you totally drain your system, use six, if you just do the stat with minimal coolant loss use four

(someone confirm this for me)

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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One more thing guys, use an AC DELCO stat, not aftermarket

By the way, you do not need to remove the water pump cover to do the thermostat, only to do the water pump, so my inclusion of the COVER and COVER seal above was wrong...

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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Make sure you don't put the thermostat in backward. It's easy to do and not pleasant to discover.

CTS-V_LateralGs_6-2018_tiny.jpg
-- Click Here for CaddyInfo page on "How To" Read Your OBD Codes
-- Click Here for my personal page to download my OBD code list as an Excel file, plus other Cadillac data
-- See my CaddyInfo car blogs: 2011 CTS-V, 1997 ETC
Yes, I was Jims_97_ETC before I changed cars.

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Thermostat is to big ~~~Headed to the part's house for the updated version I believe was spoken of as they say they have it~~~JM

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The new thermostat has a pin on one half that's loose , a small deal with a small head on it. The old one didn't have this relief deal or whatever it is~~~Does it go on top or bottem?~~~Thank's to all~~~JM

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Thermostat is to big ~~~Headed to the part's house for the updated version I believe was spoken of as they say they have it~~~JM

I am not sure what you are saying but there is no updated version of the thermostat. There is an update to the water pump cover, but you dont need to remove the water pump cover to do the thermostat, I mis-spoke above. The stat has a long tail on it that sticks into the coolant. Here are a few interesting photos

Where thermostat goes into the water pump cover

WaterPumpenginemount22.jpg

Another View

WaterPumpenginemount23.jpg

Old and new covers, with thermostat location revealed

WaterPumpenginemount24.jpg

AC DELCO stat

WaterPumpenginemount34.jpg

Photo of stat sticking into the coolant passage, (this photo excites me for some reason, :lol: )

WaterPumpenginemount37.jpg

Photo of stat adapter in place

WaterPumpenginemount38.jpg

Here is an interesting photo of my 1/4 inch breaker bar in the water pump tensioner, you lift to release the pressure on the belt

WaterPumpandRadiator008.jpg

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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The wrong thermostat was special ordered by a new part's person but they had the correct one. The littlegold or brass looking deal is in the picture you have put up of the thermostat in place. It look's like an earing stud they put in gal's ear's when they first get pierced~~~It's loose~~it wiggle's in and out~~~I'll put it like your picture is ~~~Thank's alot~~~Got to be in Houston later and I was just doing this as the car has 94000plus mile's and I replaced hose's, coolant , etc.~~~Really appreciate the ~~~well, everything~~~JM

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The wrong thermostat was special ordered by a new part's person but they had the correct one. The littlegold or brass looking deal is in the picture you have put up of the thermostat in place. It look's like an earing stud they put in gal's ear's when they first get pierced~~~It's loose~~it wiggle's in and out~~~I'll put it like your picture is ~~~Thank's alot~~~Got to be in Houston later and I was just doing this as the car has 94000plus mile's and I replaced hose's, coolant , etc.~~~Really appreciate the ~~~well, everything~~~JM

Hope it works out for you. Glad we could help. Consider being a supporting member, it has a few perks and you help support this terrific resource for your Cadillac

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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What is a supporting member? I'll do it!~~~JM

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Click on "My Controls" at the top of the page to the right of center to bring up your Control Panel. On the left near the bottom, you will see a link "Purcahse Paid Subscriptions." Click on that and read the page there. It's $20 per year for us individuals. Some vendors and such may need the $10 per month subscription but I think that's overkill for an individual.

I'm proud of the big red "Supporter" below my avatar. Caddyinfo supports me, I support Caddyinfo. I came to Caddyinfo to solve multiple problems and did so with competence and confidence with the help of the people here. I try to give back with my subscriptions, my FSM, my general automotive background (mostly not Caddy, unfortunately by quite versatile), and my time.

CTS-V_LateralGs_6-2018_tiny.jpg
-- Click Here for CaddyInfo page on "How To" Read Your OBD Codes
-- Click Here for my personal page to download my OBD code list as an Excel file, plus other Cadillac data
-- See my CaddyInfo car blogs: 2011 CTS-V, 1997 ETC
Yes, I was Jims_97_ETC before I changed cars.

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ok~~~JM

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Thanks Jim

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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  • 1 year later...

I'm putting a new thermostat in my 2002 ETC and have a couple of questions.

1. Can I put the tablets down into the housing before I put in the thermostat? I assume I grind them up some first, right?

2. Before I purchased the car, in January 2007, a Cadillac dealer changed the Dexcool. My memory is that the dealers stopped using them at some point generally. Can I assume that they didn't put in the tabs, and put in the 5 in the package?

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I would rotate the thermostat when you put it in so that the brackets around the sensing element (see photo five in post #15) so that it isn't in the flow of coolant. That's just me.

Check the look and smell of the coolant. It's been three of its rated five years. Now may be a good time to change it. If you do, you can bring it to 50-50 and use five sealant tabs now. I would put them in the radiator hose, not behind the thermostat, only because that's what is recommended.

CTS-V_LateralGs_6-2018_tiny.jpg
-- Click Here for CaddyInfo page on "How To" Read Your OBD Codes
-- Click Here for my personal page to download my OBD code list as an Excel file, plus other Cadillac data
-- See my CaddyInfo car blogs: 2011 CTS-V, 1997 ETC
Yes, I was Jims_97_ETC before I changed cars.

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Before I purchased the car, in January 2007, a Cadillac dealer changed the Dexcool. My memory is that the dealers stopped using them at some point generally. Can I assume that they didn't put in the tabs, and put in the 5 in the package?

Since GM stopped using them, the dealer most likely did not put them in. Before I quit using them I had some warranty work done that required opening the cooling system. I gave the dealer the tabs and told them to install them and they did not, even at my request. Dealers follow GM procedures.

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  • 3 years later...

hello folks this is my first post,i have a 97 deville 4.6 northstar and I just replaced thermostat.is there any way that air can be purged from system.the running temp seems to have went up about 10 degrees. Ive read about air being a problem but nothing about how to remove it...

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