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?

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

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.

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

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

I replaced the radiator already and it still gets hot

There is no other leaks

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 !!

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

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

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

Anyone's cadillac still over heating?

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

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

Or radiator

I sold mine it was head gaskets

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

I have a 2001 Cadillac deville

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

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

Try changing coolant reservoirp

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.

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.

Thank you

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.

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 .

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

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

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

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.

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.

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

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

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

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

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.

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

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

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

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

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?

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....

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.

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

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.

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

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

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

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

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

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

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.

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

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

My Wife has a 00 Cadillac Sedan Deville with a Northstar Engine and it blew the Head Gaskets at 68K. Our local mechanic replaced the Water Pump, the thermostat, and the overhead gaskets to no avail and it continued to overheat. He told me to junk the car since he felt it was blown head gaskets. Took the Cadi do our local Cadillac dealer, they did a pressure test, and confirmed that the Head Gaskets were blown and they estimate was $7K to fix it. After 5 months, I finally found a Cadillac Mechanic who does this fix properly using the Huhn Inserts. True that the engine must be pulled out from the bottom, it is labor intensive, and overall, the job takes three days. My guy charged me $3K and now we have 75K on that engine and the car runs great. Email me at toetoe1@aol.com for my mechanic who is near Saddle Brook, New Jersey.

Tim, it's not only 96-99 Northstars - the blown head gasket problem continues through the early 2000s as well. The engine bolts are not the problem- it's the threads used in the block. I fear that your posts may lead someone to believe purchasing an early 2000s deville avoids the head gasket issue. I maintained my 02 Deville well, and the gaskets went at 245,000km. It is unfortunate as these cars are otherwise wonderful to drive... Several upgrades were made to the engine from 96, and the issue is not as bad as late 90s, but the early 2000s still have this problem. Js08016 is correct to relentlessly warn owners or prospective buyers of the problem- they are dealing with an imminent blown head gasket that will not be worth fixing considering the value of these older caddys...

Hello I have a 97 Sts 187km it doesnt overheat but drinks coolant and smokes white big time...any ideas ? The car is having a great time smoking and drinking and I'm like a worried parent...also getting rough idling as well ...no leaks I find and temp gauge is just past 1/2 should I use that radiator add stuff to help seal the gasket?

2003 Deville major over heat problem. I just went through the overheat with a good thermostat (I replaced it anyway) , a good belt and water pump ----- a FULL expansion tank --- tried the heater trick -- not a chance ---- what the hell ? --- then I got to thinking - -- when I pulled the thermostat there was almost no coolant in the hose -- sure enough , hose didn't feel like there was water in it --- I pulled the upper radiator hose loose from the water pump and poured coolant into the hose ---- it took about 1/2 gallon the first try - - put the hose back on --- started the engine --- felt the hose, .... it felt dry again --- shut engine down pulled hose loose from pump and filled it again --- started engine ----- dry hose again ----- I did this routine at least 6-8 times before it seemed to keep coolant in the hose ----- this time I let the engine run ----- it came to mid temperature and the thermostat opened & I got heated water into the radiator hose and pressure ------ I took it onto the highway for a 10 mile run --- perfect temperature !!! keep in mind, it had heated up to the point that the over temp shutdown had kicked in --------- seems like I have a cure --- AIRLOCK was the culprit (this is a car purchased at an auction and had sat for over a year --- I drove it 30 miles and it suddenly overheated -------- Cadillac dealer checked it out -- the mechanic charged me for his diagnosis of blown head gasket but they could put in a new engine for $5k ------- I wasn't buying it --- water in the expansion wasn't going down, and no sign of moisture in tailpipe ...... I'm just an electrician that is 70 yrs old --- we'll see now !!}

99 DeVille overheating rapidly first cold day im driving it mid 30s the heat isn't blowing warm air.

If it turns out to be a Blown Head Gasket (Famous Problem in Northstar Engines) check with Norm Huhn for his Cylinder Head Bolt Repair Kit as well as Mechanics in your area who know how to fix it. Our repair, thanks to Norm, cost $3K total. http://www.huhnsolutions.com/cadillac

SO @Js08016 Jim Your saying If I see a 99 cadillac with a northstar engine and 98000 km's or 60100 miles I should avoid buying it because that head gasket is going to give me nightmares in the near future.

Okay, so a lot needs to be cleared up here. Jim is partially correct in asserting that one needs to be wary of Northstar V8s. This much is true. But as is the case in most things in life, dealing in absolutes is rarely a reflection of reality. Like 99% of engines out there, the Northstar is neither great nor awful; many variables contribute to how good this engine can be for you. So before Jim sends you running for the hills, allow me to give you the real facts you need to know. First off, and as someone mentioned, the "head gasket" problem is not really a true head gasket problem, but a HEAD BOLT problem. The issue is that GM put head bolts in the Northstar that were neither long enough nor had a coarse enough thread pitch to properly stay in place in the engine block. The Northstar has an aluminum block; aluminum blocks are known to contract in extremely hot temperatures. Northstars are terrific motors until they overheat for the first time, or after the first few times - once this happens (bad water pump is a common reason, broken thermostat being another, coolant leak, etc), the aluminum block starts to contract. Without the proper head bolt length and thread pitch, the head bolts couldn't withstand the contractions of the block, and pulled out of it. Once this happened, coolant would leak into the combustion chamber, burn out the exhaust pipes (hence the "white smoke"), and the engine would overheat worse than usual, therefore making the problem worsen even faster. As far as a repair price, Jim is only right in saying it'll be over $3,500 if you have it done at the dealership; there are several shops that'll do it for anywhere between $1,500 for a suspect job, to $2,500 for a reputable one. It requires putting inserts into the block (Timeserts, for example) with new head bolts, to keep the new bolts in the block. Done right, the repair should last the full life of the vehicle - the problem is totally solved. Still here? Good, I'm almost finished. I'm sorry, but there needed to be some serious clarification here! Now, all this being said, not all Northstars are the same, and the head bolt situation is not the same either! The worst years to get the head gasket issue, as Tim rightly stated initially, are from 1997-1999. Here, Jim is right on; if you are looking at a car with the 1997-1999 Northstar, and the owner DOES NOT specifically say that the BOLTS WERE REPLACED THE RIGHT WAY, stay away! You will almost certainly have a head gasket failure. 1993-1996 are not perfect, but are far more reliable than the '97-'99 versions (GM cheaper out on the 97-99s with the cap head bolts - your standard GM cost-cutting!). In 2000, GM used new head bolts that had the same thread pitch (a fine pitch), but was considerable longer than the 97-99 bolts. This lessened the likelihood of a gasket failure by a decent amount, but by no means ended the problem. It wasn't until 2005 (or halfway through 2004, to be precise) that GM finally used a long head bolt with a coarser, more grippy thread pitch that could withstand any potential contractions by the aluminum block should the engine ever overheat. In the 2005-2011 Northstars, therefore, the head gasket issue was basically solved, almost 13 YEARS after the engine originated! Unreal. But, if you get a 2005-2011 Northstar, you should have no problems with the head gasket, barring an EXTREME overheating case, which is highly unlikely. Post-2005 Northstar owners, rest easy! Lastly, let me say this: if your Northstar V8 has never overheated, you are good to go, regardless of the year. The issue is, many looking to get a used Cadillac with a Northstar can't verify that it has never overheated. My advice? First, try to get a 2005-2011 Northstar if you must have one; I admit, they are fantastic engines to drive, sound great, and come with special cars. If this isn't possible, get a Northstar made after 2000. I would avoid all 97-99 Cadillac Northstars like the Plague. If you can find a low mileage example, get a block test kit from autozone - they're super cheap, and will save you a ton of mney down the road. If the test shows you have good gaskets, have a.good mechanic look it over. THE COOLANT SYSTEM IS KEY!!! Make sure the coolant is clean, ie, it has been flushed recently. The most important maintenance Northstars need is constant coolant flushing. Read that sentence again. I flush mine once a year at least. This allows for good, new coolant to be circulated through the engine, and keeping it from overheating. Also, replace the thermostat and water pump, and any cracking radiator hoses, as soon as you buy the car. It'll cost a bit of money up front, but in the long run, it'll save you thousands. Remember, you want to keep this engine cool! Get the whole cooling system looked at by a good mechanic. I would also try to find a Northstar Cadillac owned by a senior citizen it's whole life - they drive 'em softly, and they likely have never overheated. If you don't follow these precautionary actions, you could get the head gasket failure down the road. So, I hope this helps a bit. Dnt just run away because your Cadillac, or potential Cadillac, has a Northstar. Do your homework. Know the different years of the engine, and which are the best for reliability. Chances are, if your follow these tips, you'll be perfectly satisfied with your Northstar V8, as many others who have taken care of them have. Additionally, head over to cadillacforums.com and go to the Northstar section, all this info is there, and so much more! Good luck, I hope I have been of at least a little help to some of you.

Got a 2000 DeVille just started overheating, Northstar in the car.... Put coolant in it and it keeps overheating please help?

Songuku, get yourself a "block test kit" from your local autozone or like car parts store. This test kit is simple to use, I know autozone has them and they will tell you how to use it. If the test shows a blown head gasket, you're looking at about a $2,500 dollar fix. Check back here with the results. How much did you pay for the Deville?

Why is everyone stating it's a head gasket first of all,Check your oil to see if there is water in it,It will have a milky appearance,That is how you see if you head gasket is warped,Now the best way to do that is to drive your car while it is running hot,Hence the warped gaskets from the heat,This is not an Engine problem,This is a Driver ,Impatience problem,...So...just stating a fact...

Check your coolant fans , if it's a blown (warped head)gasket There would be more signs...Click click..Driving your car hot warps the heads...so when the Gage goes towards the red,Pop it in nuetral and coast,Wait a few check your levels on oil fluid Dex Antifreeze 5050, if it is warped gaskets the vehicle would not continue to run continuously.Engine lock..Locked no car move,If engine no run ,No Overheating,In my limited experience.A thermostat needs to be checked if it runs hot quick as hell and there is no remedy ,Quick fix,I.e. Run your heat.,Water pumps usually leak,Radiators smoke,Coolant fans are another cheap route to go before,Oh Hell No This Car is blown head gasket let's trash it...Low Engine Oil can also make it run hot.. Leaks in Hoses from Radiator to Resovior.......

Just to clarify we arent talking about a northstar so lets be on the same page here we are talking about the 4.9L V8 PFI engine

Mase, you have no clue what we're talking about, obviously. The top of the thread clearly says it's for a 2000 Deville, which only came with a Northstar, not the 4.9 PFI. Pay attention, the rest of the class is already on Chapter 5.

I have experienced the picture with the coolant running down the driveway recently. I found out that it was that plastic t connector that goes into the heater through these back engine firewall...it split. If you find that this is your issue, you have the ego purchase the he gone whole assembly. The t connector is molded into the hoses.

Hate hearing bad crap about the Northstar caddy motor ,not a bad motor! Bad head bolts, believe it or not other smaller issues account for 80 persent of all overheating issues ,with this motor get your fax strait ,don't steer people wrong with your b.s.

2001 elderodo 4.6 north star over heats non stop don't think its the gasket I keep having to put fluid in it though don't seem to know where that's going no apparent leeks the oil looks good and no smoke out of the exhaust the weird part is as soon as I put coolant in it it stops over heating for a couple days then it goes right back to getting hot and I have to put more coolant in so on and so forth

Answers, how about questions? Like many Cadillac owners with the Northstar, my issue is the engine getting hot, and though it cools down again, if I wait with the engine running, in about another 20 miles, I must let it cool again. Changed the thermostat, changed the temp sensor, changed the thermostat, flushed the coolant fluids fluids,added 50/50 dexcool, observed both fans spinning, observed coolant coming out the purge line bolt when line disconnected and engine running... After I did the easy stuff, I checked with the Block Test blue fluid which quickly changed to a greenish yellow, repeated the block test on the exhaust coming out of the tail pipe, same color change. now I am looking for a place to change the head gasket, way too much work for me to do it myself, right from the start of dropping the engine, I award those who do it with gratitude and thanks. Anyway, to save money, is a new re-man engine worth the investment or would a head bolt/stud change solve the issue cheaper, and allow for a look at the bottom half for possible cracked bolts/studs? as this week is time for me to find the correct shop to do the job on my 2002 Cadillac Deville DHS, with 111000 miles on it. Plus, how do I make sure they use the proper manifold distribution plate, and lower conversion kit, and how do I make sure they use the beefier studs instead of time-serts? something like the GM big serts or the Northstar performance studs?

If youve replaces the lines and radiator and its still leaking i would check amd see if the nut on the front of your fans is rubbing the radiator. I had the same issue and had to replace the radiator 4 times before i realized what it was. (Fyi it can run without fans i wouldnt recommend sitting idle for longer than 3mins tho)

I drove my 98 DeVille home for the first time yesterday. Paid 2500 for car with 144k because I was in love and didn't really recognize the three lies the old man told. Well it overheated on the way home and said stop engine at lights so I took it to service station where I met a very understanding mechanic. I want this to work out. I am going to try the things here in the order of easy/inexpensive to hard/ pricey. Someone mentioned a new engine for $5k. Would that mean no problems anymore? Like, I could drive it 250 miles at a time in the summer? My husband is going to take this pretty hard. So far, he knows that the mechanic showed me how to hold the gas nozzle just so in order to get more than 35 cents of gas at a time. We dropped it off today for a tune up/ once over to diagnose her issues. I've named her Janice.

She ^ is leaking coolant, so that means maybe head gasket(s)/bolts not blown yet...

Janice, Hate to say it, but it sounds like you may have a blown head gasket. I obviously can't say for sure, since I haven't seen it, but it looks very likely. Before you do ANYTHING, get a block test kit from Autozone. It's a cheap way to find out if you have indeed blown your head gaskets (being a 1998, it's likely). The liquid in the test tube will turn from blue to yellow if it detects exhaust gases in the coolant tank. Again, do this BEFORE you try anything else! It could be a water pump, thermostat, etc, but try this first. Best of luck...report back!

Will a 92 F-150 with a 4.9 L straight 6 radiator interchange with a 99 Cadillac DeVille with a 4.6 will the radiators interchange with each other

I have a 2002 Deville with only 70,000 miles, it keep overheating. I have replaced the radiator thermometer. and water pump but it still overheat. It runs great but I keep getting that check low coolant sign on the dash.... I can use some help!