My cadillac gets hot and my car says that the engine is overheating. I put coolant in it everyday and it throws out all of the coolant in the coolant reservoir. Is it the thermostat or the water pump?

Asked by Sep 01, 2012 at 11:23 PM about the 2000 Cadillac DeVille Sedan FWD

Question type: Maintenance & Repair

My car gets hot every time I drive it. I have to put coolant everyday sometimes twice a day. I think it may be the thermostat or the water pump, but I'm not for sure. All I know that it gets hot and throws out all of the coolant in the coolant reservoir. I just want to know what's going on before I have to get it fixed. How much I'm going to spend.

73 Answers

294,125

Do you have any other leaks besides the overflow tank?

29 people found this helpful.
79,275

These cars are notorious for blowing head gaskets. To do the head gaskets correctly you're looking at about $3500.

8 people found this helpful.
590

if there is no leaks its def the head gasket puts compression into the coolant system causes it to blow out best bet replace engine find a certified used one to save money or buy a new one for what it would cost to fix the one u have i replaced the headgaskets in my 99 eldorado replaceing them was the easy part the problem is once they over heat the threads in the block for the heads pull an have to be drilled and replaced with helicoils that is a major pain and most of the cost

8 people found this helpful.
170

Wish I'de seen your post 2 years ago. I had the same prob with my 04 DeVille. Changed out the thermostat twice. I'm told is a flaky part that will go bad again and again. Eventually after all that nonsense my radiator blew up then shortly thereafter the water pump. And now were back to square one with the 'over heating' issue.

17 people found this helpful.
260

I changed my relays to the fans on my 1999 Cadillac Seville stops over heating

26 people found this helpful.
50

I'm having the same problem with my 1999 seville.. i have replaced y thermostat 3 time even use a felsaft one also still not not work

5 people found this helpful.
140

I replaced the radiator already and it still gets hot

7 people found this helpful.
140

There is no other leaks

7 people found this helpful.
220

Replace coolant tank and there is a screw at the end of the purge line at the end of the block replace it or clean it out and that fix mine and I'm happy she"s rimmimg like new!! Had about ten different mechanics tell me it needed head job that the heads were no good yeah right !!

22 people found this helpful.
380

Brian what year is your Cadillac deville I have a 01just put brand new radiator and hose and it's still overheating it ran great for two days with no issues until today and put a new cap on as well we are stumped

27 people found this helpful.
380

Fans work no problems with them and my heater core is not leaking

5 people found this helpful.
80

I have the same problem, change water pump, clean the coolant resovior and thermostat,

8 people found this helpful.
420

Anyone's cadillac still over heating?

26 people found this helpful.
440

I have a 2002 dhs. I replaced the thermostat, radiator and water pump. It still overheats. No leaks. Anyone have any suggestions?

44 people found this helpful.
640

I have a 2001 cadi deville ..im having a overheating issue ...car says check coolant it wont hold any coolant if i drive 10 mikes it overheats and makes bubbling noise...head gaskets..waterpump. or thermostat

60 people found this helpful.
640

Or radiator

4 people found this helpful.
380

I sold mine it was head gaskets

6 people found this helpful.
320

My cadillac is over heating and I put in a new thermostat and its still acting up

17 people found this helpful.
320

I have a 2001 Cadillac deville

15 people found this helpful.
420

Anyone with a 1999 cadillac seville sts over heating problem, I can probably help you txt 928 300 5732

16 people found this helpful.
60

I just got a 99 sts with overheating issues...

6 people found this helpful.
50

Try changing coolant reservoirp

5 people found this helpful.
10

Same problem, 99 Deville, mechanic took out the thermostat, and put in some head sealer, now it's ten times worse, use to be able to go 15 miles before losing water, now it overheats in two miles. He did some test and found hydrocarbons in the resevoir, now after the treatment, he says probably a warped head. Worse mistake I ever made buying a used Cadillac, they are junk.

1 people found this helpful.
10

I have a 97 Eldorado. I replaced radiator, hoses, temp sensor, temp sending unit, and fan relays. Still over heated. Took it to dealer and they said it was my head gaskets. 500-3000 dollar repair depending if gaskets were done for. Replacing engine now. Any ideas on how to prevent it from doing it again? Help really appreciated.

79,275

Unless you replace the engine with a freshly rebuilt crate motor, it will happen again. In fact if you're getting a used engine it may also have a blown head gasket. Northstar engines are notorious for blowing head gaskets. They all do it. It's not a question of "if" it will happen it's a question of "when". Sooner or later they all blow! HTH. -Jim

8 people found this helpful.
10

Thank you

1 people found this helpful.
79,275

You're welcome. Glad to help. -Jim

2 people found this helpful.
260

LISTEN TO ME. I LOOKED IT UP ON YOUTUBE. IT REALLY WAS THE PROBLEM. REPLACED JUST ABOUT EVERYTHING. MECHANICS TOLD ME TO GET RID OF THE CAR. I REPLACED THE COOLANT FILL TANK. THE BIG BLACK ONE. PROVLEM SOLVED. EVERYONE THAT HAS DONE THIS HAD THEIR CADDYS OVERHEATING PROBLEM FIXED. THE PART IS UNDER FOURTY DOLLARS ONLINE AND WILL SAVE YOU ALOT OF TIME, MONEY, AND STRESS.

20 people found this helpful.
70

Donald I will try what you say replace my tank mt 03 deville chech cooliant light alwsys on but I hv cooliant in there my temp level goes 1 pass halfway then goes bak down I hope it's. My tank I've. Changed everything else except. That .

2 people found this helpful.
70

Check cooliant message is on my tank looks bad to me will a new tank fix that. Is the senor bad will that cause issue bad tank

5 people found this helpful.
110

I got a 2000 Cadillac DeVille that overheats could it be my thermostat or head gasket

3 people found this helpful.
79,275

Head gasket. Especially if it's a Northstar! HTH. -Jim

3 people found this helpful.
110

I got a 2000 Cadillac DeVille and it over heats and it still run good no missing out in the engine can somebody please help me it just overheats when I drive it no white smoke

8 people found this helpful.
79,275

Check for exhaust gases in the cooling system. NAPA sells a chemical for that. But, again, if you have a Northstar it's 99% going to be the head gasket. HTH. -Jim

4 people found this helpful.
80

After spending 8k on my 2001 DeVille and all of the above fixes we found it still overheating. Car idled fine but 3 miles on the road it would overheat again. Was nothing left but scratching our heads. Went thru four auto shops and many mechanics and finally one found the catalytic converters clogged. Heat had no where to go but backwards. Replaced and car is like new. Wish I'd known that when it began. Hope this helps.

8 people found this helpful.
79,275

Unfortunately, DeVilleCrazed, your car was not properly diagnosed. A clogged catalytic converter should have set a trouble code in the computer (PCM) and triggered the check engine or service engine soon light. A restricted exhaust system will also show a loss of power from the engine. The cooling system should have been pressure tested as well as checked for exhaust gases in the coolant. Northstar engines all blow head gaskets sooner or later. It sounds like your mechanic(s) jumped to that conclusion. I am very sorry to hear that you spent $8000 on this car before finding out it was the catalytic converter!! Personally I would have junked it before doing the head gaskets. To me it's not worth it on a 16 year old vehicle. -Jim

4 people found this helpful.
30

Its NEVER really the head gasket its its the bolts that holds the engine heads together - theyre notorious for that. BUT I was told by an honest mechanic that 9 times out of 10 you have to lift the engine up to replace them . Also make sure your catalytic converter isnt clogged that can cause the needle to rise to hot also.

3 people found this helpful.
79,275

City93942, you are correct in that the head bolts pull out of the block on these engines. However, the engine and transmission assemblies must both be removed from the bottom of the car to do the repairs. There's no other way. It's very labor intensive and on an older model not worth the expense. There is a "button kit" that needs to be installed as part of the repair. It's basically a set of beefed up Helicoils to repair the damaged head bolt holes in the block. In 2010 a friend had the job done, at a local garage. Not the dealer. On his '97 Eldorado. It cost him, then, $3500. Parts and labor. He knew what he was getting into before he bought the car for $500. It was a "project" car not his daily driver. He also had the money to spend. But for someone who's funds are limited and they're using the car as their primary transportation, it's just not worth it. -Jim

2 people found this helpful.
30

I have an 03 Cadillac deville . I changed the water pump, thermostat, radiator, dashboard, heating censor, fans, and engine won't overheat but in the dashboard the heating lines go up and down. It's driving me nutts

3 people found this helpful.
50

I checked out a YouTube video and the master mehincanic said the most common problem with overheating and the lost of coolant was the over flow tank so dont go with the so called head gaskets are blow

5 people found this helpful.
30

my 98 deville only over heats on highway - only 98K miles AC and everything else works great.. any thought?

2 people found this helpful.
79,275

Head gasket. HTH. -Jim

30

Js08016 ... was that meant for me? havabrain? sorry new here and I havent bought car yet

1 people found this helpful.
79,275

Oops, yes it was. Sorry for not clarifying that!! If it has a Northstar engine in it you don't want it!! Not at that mileage with an overheating issue!! It's 99% going to be the head gaskets. All Northstar engines blow head gaskets. The only way to do the repair is to remove the engine and transmission together from the bottom of the car. There's no other way! You'll be looking at upwards of $3500 to fix it. That's probably why the seller is selling it! Keep shopping! HTH. -Jim

1 people found this helpful.
30

Replace the reservoir. Dies your dash computer show check coolant and it's got plenty. Blew my mind . replaced mine now she's running cool. Try it you won't be disappointed.

3 people found this helpful.
20

I have 2001 DeVille have replaced radiator,hoses thermostat ,sensors ,water pump intake gasket coolant tank.purged system twice.no leaks,no water or steam from exhaust.even went to heavier grade of oil.still overheat in less than half mile.also checked for cracks in heads and block found none.pressure check twice.still overheat.fans work fine

2 people found this helpful.
79,275

Test for exhaust gases in the coolant. If you have a Northstar engine I bet it's a head gasket. All Northstar engines blow head gaskets. HTH. -Jim

2 people found this helpful.
20

Wouldn't pressure test detect a leak.there is none even when registering hot no leaks.check coolant level stay on even though it's full

79,275

Not always on a Northstar. HTH. -Jim

70

What is it about the coolant reservoir that makes it over heat? How would replacing it fix the overheating issue, I replaced radiator, thermostat, water pump seems ok, does not smoke, runs perfect no miss, have NOT checked for gasses in coolant but why would replacing the res fix the issue from what a couple people have said

6 people found this helpful.
70

My issue is that the the water boils out of the tank when running, then I shut it down and it sucks the coolant back down til the tank is almost empty, I'm leaning towards head gasket, trying to see what I can do to get car running for my parents, 2002 deville

1 people found this helpful.

I have a 1998 cadillac deville and it overheats almost everytime we drive it we can't drive very long without it happening we've changed back hoses and radiator and just about everything but I'm honestly thinking it's this North star engine it's horrible and there's a hose right in front of the engine that looks like it exploded and someone tried taping it together I'm not sure which hose this is but likely it needs to be renewed but I just don't understand why it runs hot we keep coolant in it?

30

If you pressure test your Cadillac's cooling system, can find no leaks, and have replaced the thermostat and what not... Then it may be that you have an air leak between the reservoir tank and the pump. This is a weird "one way" type of leak, as what happens is that when you shut down the car, and the coolant cools, it then sucks air into the system where it becomes trapped. If you can sometimes hear "gurgling" inside the car when you start it (via the heat exchange), that is a good indication that is what is happening. When enough air has been trapped, and it makes it way to the water pump. The water pump then looses its prime and the overheating commences. You can sometimes stop the overheating whilst driving by taking it out of overdrive (into 3rd gear), as that speeds up the pump (which runs off one of the cams via a belt) enough to re-prime it. This can be the reservoir tank itself, or one or more of the hoses that has become too stiff, and does not seal correctly. This cost me a bit over $1200 at the mechanics to fix, and he still didn't figure it out (I DID). This is why MOST CARS have the dammed hose out of the reservoir tank go DIRECTLY to the dammed water pump....

3 people found this helpful.
10

Gary Rosenthal says it's not the cadillac its because of your nice stylish sleek Cadillac that vandals possibly retaliating to your glorious lifestyle contrary to the vandal's misery (misery luvs company),or that you may have been targeted by haters and they have mechanics SKILLS to destroy cars because they hate on poor innocent people because they are jealous of the best. Check around the quarter panels where the haters can get to by reaching and sliding underneath. Without a back crawler and sometimes they even lift the car somehow real quickly to pull hoses and crimp them thereby obstructing water coolant to destroy engines when that causes water to overheat cause the water stays hot unable to circulate through the radiator to cool down and fans working cause the radiator water is insufficient and dehydrated.

10

Also check your hoses for blockages it's timely but worth it my heater core blew up because I did not check the hoses and heater core water was hot and it's in the passenger compartment right above a passenger toes also check and even replace thermostat check around seals near water pump and flush out the cooling system with radiator flush if you have a small leak get an engine additive called "SEAL UP" and that should stop most leaks nls blocks sometimes make sure the coolant is the same color that you put in it and make sure you had those pellets Cadillacs need Dex Cool or a coolant formula from the auto parts store that actually cool the engine down more and it's green color sometimes flush the engine put that in and drive the Cadillac full throttle again like when you first got it and put that in it should be okay for a while just Add Water if needed and also check your oil sometimes these cars just use it up somehow or sometimes people that drain it synthetic oil is expensive people steal it they stole mine for 5 quarts is about $75 Dexcool expensive stuff protect your car getting alarm put cameras everywhere do what you got to do to stop these people from destroying our nice Sleek stylish Cadillacs and most importantly don't take the law in your own hands call the police if you catch him or her and have evidence on camera downloaded to the internet to submit it online to these blogs and to the police departments

40

Hi: i just bough a deville 2000, it was overheating. Alleguedly took it to the local repair shop for an alternator replacement. I found out both cooling fans'relaus were inserted backwards and fuse for ac clutch burned out.

40

Relays, sorry. End of the problem, i also replaced air filter and thermostat, end of the problem.

40

I live in Jerome id, 83338, bought cadillac here in jerome (shop in jerome too, seller argued he took it there for repair)

40

Ps: i installed a new thermostat, same as previos one, compared them, but both are of the wrong lenght. Yup, car overheated again. Right thermostat

2 people found this helpful.
40

Should have enough room to be able to open. Reservoir water boils and heater stops heating. Solved!!!

2 people found this helpful.

I discovered my coolant nipple is leaking. It's a little tiny connection that requires taking practically everything out to get to. But the nipple itself is less than $10. You have to take a long handled mirror to even find it under the hoses. The only reason my mechanic knew to look for it was because another customer came in to have everything replaced on his Cadillac Deville and as he took it apart he couldn't find anything wrong with anything heat related until he got to the nipple and that's where the leak was. He replaced the nipple & the thermostat from all the over heating and it worked like a champ. Another person on youtube found a thin hose that was blocked, cleaned it out, put it back on & it stopped overheating. https://youtu.be/6l4_5f3SoV4

I have the caddy deville limo 2004, after changing most of everything , water pump etc, the real problem was the fan. When we drove the car after 15 minutes it started to slip above the overheating level. On colder days didn't happen as much. The fan was shutting off after about twenty minutes and the car started run badly , no compression etc. I changed the fan and those square large fuses. they would almost melt. So I changed the fans. That didn't work. It was actually the electrical box which cost about $300. After that was replaced it was like a new car. When on high spedd it clears out all the heat. Dave in central islip limo repair shop was the biggest help and probably out of 10 mechanics that new almost immediately and in one day was fixed. Amazing place and a real mechanic and charged a fair price.200 lambert ave copaigue a-1 limo repair amazing

10

Replaced resovir,waterpump,thermostat, and it still runs hot what can i do to fix this 2000 deville northstar we still scratching our heads n mechanic still hasnt fixed it yet runs hot after driving 5 miles any ideas

1 people found this helpful.
79,275

It's going to be the head gasket and not worth fixing. You're looking at upwards of $3500 to fix it. The vehicle is 18 years old. Time to move on. HTH. -Jim

10

Found this website http://www.rxauto.com/northstar-info.htm and they sell a Thermagasket kit to correct the notorious Cadillac Northstar engine cooling system vapor locking problem that occurs. I have had several mechanics try and diagnose my cooling system issue and I have already replaced the coolant tank, radiantor cap, water pump and hoses and the problem still persists but I see no water leaking from the car? Their website hits the nail on the head with all the exact symptoms I am seeing in my 1997 Cadillac Deville. The mechanic where my car is currently at stated he would install the kit once I get it as they are puzzled as well as why the car continues to overheat. More to come once the kit is installed and car driven extensively.

1 people found this helpful.

Js08016 - my husband own two cadiallic and they was in the shop and they said they running wonderful but no noise in gasket head and only we fix water pump and radiator was just fine they replace head gasket for 400 and running fine but one problem machine go become red beam come on what cause it but I heard 40 dallor part will stop overheat

Js08016. I registered to this site so that I could call you out. SHUT UP! give it a rest dude. You have posted on this like 20 times saying head gasket! No people not all northstars just randomly blow their freakin head gaskets! 97 thru 99 I believe are made with short head bolts. Those are the years to avoid. They did however fix the issue in either 2000 or 2001. If you have a blown head gasket you will have milky oil. If you don't have milky oil then chances are your head gaskets are fine. However! Overheating the car too much CAN cause the head gasket to blow so you will want to find and fix the problem quickly so that you DON'T blow a gasket. Failing water pumps are fairly common in the devilles. And if I'm not mistaken the radiators (at least in my 01) has the oil cooler built in which are known to leak oil into the cooling system. Replace radiator or keep your coolant flushed regularly. Also northstars are known to leak oil. Keep your oil level topped off. If you dont and you run it low on oil it will destroy the gaskets and your motor. I got my 01 deville 2 years ago. It had 207k miles. It now has almost 241k and still running strong. Northstars aren't bad motors. They just need to be maintained more than an average motor. Unless it's a 97-99. Those northstars ARE bad because of the short head bolt issue

79,275

Welcome Tim. I'm flattered that you joined the website just to talk to Me! For starters I will not "shut up" or "give it a rest". It's a known fact that these Northstar engines all blow head gaskets sooner or later! It's a poorly designed engine. The head bolts pull out of the block. That's what causes the head gaskets to fail. There are, of course, exceptions to every rule. Your deVille may or may not be that exception. Since you bought it with 207K on it the head gaskets along with the button kit, etc. was probably done long before you got the vehicle. Unless you've known the vehicle from day one you have no way of knowing. The head gaskets usually fail between 90K and 120K miles. Many times people post here that they've replaced the water pump, thermostat, radiator, etc. but their Northstar continues to overheat. What's left? A clogged up cooling system, worn timing chains, faulty PCM, or, you guessed it, a blown head gasket. With these engine's notorious reputation for head gasket failure, it's going to be that. Craigslist is littered with these vehicles in the $500 to $1500 range. Some are in great condition too! But they have a "blown" (Northstar) engine! Since you enjoy researching, do this. You claim I've posted about 20 times on this. Go back and see how many times it was the head gasket. I'd be willing to bet it's at LEAST 18 yes and 2 no. Once the upgrades have been done these are fairly decent engines. Otherwise, no. Something that leaks oil and coolant all over the place isn't my idea of a great engine. -Jim

Sorry for being rude earlier. My research has turned up that the head bolt problem was only with the 96- 99 models. 00-01 is when they addressed the issue by assembling with longer head bolts. My deville may have eluded the northstar curse at 240k and stI'll going. .but this is still an issue I'd like a solid answer to. Most of my research points to 96-99 being the problem years for head gaskets in northstars.

My 98 deville is doing similar to everyone elses with the over heating. I can not find a leak anywhere. Ive replaced water pump, water pump belt and tensioner, both fans , a lower hose, cleaned a few small lines out and put back on, heater core blew out and was replaced. Car runs fine at idle. I can drive 7-8 miles and it'll overheat. Ive debated bypassing some small lines to eliminate other possible doubts. And i do not believe its blown a head gasket. Oil is fine. No leaks anywhere around heads. I plan to swap the catalyct converter but beside that i am clueless. I know people say stay away from the 96-99 northstars but its kinda my dream car and im on a very low income. Any info is appreciated in advance.

Yeah the 96-99 northstars are bad for blowing head gaskets due to short head bolts. This may be what's happening with yours. Once the engine gets heated enough the head will begin to separate which can allow your coolant to spill into combustion chamber and burn out. You won't notice any leakage because it will all be evaporating out through your exhaust. The only known fix is something called a helicoil fix. That requires removal of the heads and everything however. I got lucky as my deville is an 01 northstar. Got almost 244k miles and still going strong. This may sound crazy but you could also try putting on a new radiator cap. The seals can wear out and allow coolant to evaporate out around the cap but if it's overheating in just 7-8 miles it's more than likely the head bolt issue.

Hey, I have an 05 DeVille and my fans won't turn on. It doesn't over hear per se because I only drive it across town or about max if 60 miles to the next town over. It always smells really really hot when I get there. The fans never kick on and on the dash the heat sensor never goes above half but gets there fairly quickly. Would replacing my coolant tank help with the getting hot really fast? What should I do to get the fans turned on? I've replaced all but one of the fuses to the fans and that last fuse is my last thing coming payday but that's all I know to do. Please advise.

has anyone had success with Thermagaskets Proprietory Cooling System Equalizer that "97Deville" mentioned above? https://www.rxauto.com/northstar-info.htm

Your Answer:

DeVille

Looking for a Used DeVille in your area?

CarGurus has 1,275 nationwide DeVille listings starting at $1,895.

ZIP:

Cadillac DeVille Experts

  • #1
    kikero
    Reputation
    2,320
  • #2
    Js08016
    Reputation
    2,060
  • #3
    Cynthiasmith
    Reputation
    1,840
View All

Related Models For Sale

Used Cadillac Eldorado
283 listings starting at $2,995
Used Cadillac Seville
3 Great Deals out of 258 listings starting at $1,495
Used Lincoln Town Car
28 Great Deals out of 1,476 listings starting at $1,900
Used Chevrolet Impala
420 Great Deals out of 25,855 listings starting at $950
Used Cadillac Escalade
197 Great Deals out of 12,105 listings starting at $2,995
Used Ford Mustang
247 Great Deals out of 38,236 listings starting at $1,350
Used Chevrolet Camaro
236 Great Deals out of 27,028 listings starting at $2,077
Used Chevrolet Corvette
90 Great Deals out of 14,976 listings starting at $3,620

Content submitted by Users is not endorsed by CarGurus, does not express the opinions of CarGurus, and should not be considered reviewed, screened, or approved by CarGurus. Please refer to CarGurus Terms of Use.