Where is the thermostat located on 1998 STS Northstar


Asked by Jun 26, 2013 at 01:28 PM about the 1998 Cadillac Seville STS

Question type: Maintenance & Repair

I have been told that the thermostat is located in two different places and for whatever reason, I cannot find a definitive answer. So is it located with/near the Water Pump Housing or is lt located toward the top of the engine on the driver's side. One answer indicated following the lower radiator hose and the other indicated following the upper radiator hose.  Any help would be greatly appreciated.  I need to flush my cooling system and remove the thermostat so that I can hopefully successfully add Blue Devil Head Gasket Sealer an seal the head gasket!

25 Answers


DavidH25, thanks so much for your help, I really do appreciate it! So my next question is do I follow the bottom radiator hose or the upper radiator hose to the water pump? Is there a trick that I should know about when removing it, I read a few people said it was tricky. I do not believe I will attempt this alone but I would like to be prepared just in case lol

14 out of 14 people think this is helpful.

You know what I had some stuff up but it was conflicting. But for what it's worth, the 1998 4.6 Northstar shoes it on the water pump housing

1 out of 1 people think this is helpful.

Then I found this at: http://www.justanswer.com/cadillac/4ashb-cadillac-deville-thermostat-located-northstar.html

13 out of 13 people think this is helpful.

...always going to be the water neck...every car~!

6 out of 6 people think this is helpful.

there are counterflow arrangements H25, you've owned more than one Tercel~

3 out of 3 people think this is helpful.

I believe we are looking for "the special hoseclamp" pliers that you'll use once in your life and will occupy your toolbox for life~

4 out of 4 people think this is helpful.

Thanks Judge, we need all the help I can get on this one

2 out of 2 people think this is helpful.

everybody needs one of these in one of their four mechanics boxes~

2 out of 2 people think this is helpful.

I know of no tricks for most cars, just be careful that the thermostat is seated properly in it's place or the housing will break when you tighten it

3 out of 3 people think this is helpful.

okay, you are NOT gonna be able to use "blue devil" or whichever the witch doctor recommended. You are going to have to replace the headgasket or forever have woes (I know, I cheated on my 22RE) and now have an oil leak that cannot be stopped with a wall of gelatin...it works shitty....do it right!

2 out of 2 people think this is helpful.

gonna have to bite the bullet on this one....commit to a weekend...unplug the phone, lock the garage doors, and get the right tools to do the job. Chinese ones will break and slip and cause you injury...get the best you can buy....Hans had a link to the German toolmakers...those are good if you are going to tool up for this job.~

2 out of 2 people think this is helpful.

Agreed. There is no magic stuff from a can that will seal a head gasket. sorry

2 out of 2 people think this is helpful.

Wow guys, you have been extremely helpful! Here I was thinking that something that should be relatively easy turns out to be major step one for me. Getting beyond the thermostat would be amazing at this point. This is well beyond my capability which I already knew but I was trying to gather as much info as possible for my friend who has now been elected to do the job. So many things I would like to learn but right now I am content knowing that I can change a tire on my own. Thanks DavidH25 and judge_roy for the good insight and of course all of the help and diagrams etc. As for the Blue Devil Head Gasket Sealer, not my doing. He wants to fix the car properly but just for a temp fix he is trying this. His car, his doing! I should be on here discussing my 2002 Toyota Camry SE lol, that will be my next round! You guys know anything about Camrys(-: .

remember now it was Lars Cats....do not remember what thread...think somebody erases these threads...sometimes cannot find them...they simply vanish~ooooo spoooky~

1 out of 1 people think this is helpful.

well agreed tyonnakins, you will be a mechanic if you are able to a head gasket job....did someone cook this motor on acct of a bad heater hose letting coolant out...perhaps onto the passenger footwell? and subsequent overheat as you tried to make it to the station? some body cooked this motor...look at the underside of the hood will tell a history of overheating~

2 out of 2 people think this is helpful.

David I know NOTHING about Camrys but somehow took top dog position...now's your chance for those reputation points on the camry will make you the TOP camry expert I KNOW you are ~

1 out of 1 people think this is helpful.

judge_roy, his daughter drove it while it was in the red without adding any coolant in the reservoir at a minimum. So no when he starts it, there is a plume of white smoke that comes out of the tail pipe. I am going to go against women's lib right now and simply state that car repairs (no matter the difficulty) are for males-at least most of the time and especially in my case. I am a mathematician so I can understand some of the mechanics but as far as applying what I understand...not gonna happen! Throwing the Camry out at ya anyway...burning oil but cannot see where the oil is going...not out the tail pipe, not under the car, but occasionally I will get a slight smell inside the car when driving. No worries if it cant be answered...

1 out of 1 people think this is helpful.

I know Corolla better than Camry's

I know Corolla better than Camry's but let me see what I can come up with, so okay, the motor oil level drops to a point where you have to add often? Let's start there

Nice Avatar pic....sexy mathematician~ No, it's the PCV elbow. (not egr, that's a nasty bugger what controls combustion, you don't wanna know about that one)..yes the positive crankcase ventilation valve takes the crankcase positive pressure oil air and vents it to the intake with a one- way valve...yours is messed up so the fumes got no where to go...'cept up your nose where they are trouble~ will price out the PCV elbow for ya- gimme a sec...they are a cinch to change out, just look for the hose that comes out of the valve cover and goes into the intake plenum~

hey akins, start a new thread please...install your profile pic as your avatar this time please...x+y as zero approaches infinity~

Camry category....that way our answers will be preserved for all time in the "camry" questions....okay? that was the square root of x+y as zero approaches infinity...my only calculus and learned it then forgot it for my strength of materials class in technical school~

do not know the year of your Camry.....start a new thread please~


I started a new thread over in Camry Land. Talk to you in a bit!

1 out of 1 people think this is helpful.


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