Unfortunately I did run only water. I did this because I figured if it didn't stop overheating why put the expensive dex-cool and waste it. I am going to try a different approach to fix it. I am going to use thermogasket. The guy told me it comes with a bleeder kit and the solution. He also says it has a 98% success rate on the Cadillac Northstar motor. If it don't work I get my money back. The kit is 270 bucks. Which is how much the head gasket kit costs. I am hoping it works its a difficult job and if it does it will be smooth rolling again.

 

well now knowing that you ran straight water you most likely have head gasket issues. as far as using the thermogasket ive hear it works but also later ends up failing down the road again. So just keep that in mind.

Just a little added inf about using straight water in a coolant system is ALWAYS a bad idea for a daily driven car. Water boils at 212*F and when water boils it releases air bubbles and creates air pockets in the cooling system and can cause pitting and corrosion on metel surfaces and make holes or weak spots or cracks (cracked heads). Also while the water is boiling it cant get rid of the heat and just keeps getting hotter and the air pockets start having nowhere to go. this is where the COOLANT comes into play. Coolant helps lubricate and keep a thin oily coat on metal surfaces and keeps from corrosion all while raising the BOILING point of water.

So with that being said you would have been better off just buying regular coolant and checking for leaks and then later flushing and using dexcool. Im sure you know this now, but i have run into people who dont understand the cooling system and why we need a mix of water and coolant instead of straight water. The outcome may have been even cheaper and you wouldnt be forking out $300 bucks on snake oil to fix something that could have been prevented. Im not trying to be rude in any way i just hate seeing people cut corners thinking they are saving money and then later find themselves spending 3 times that later on. $13-15 bucks is cheaper than a $3,000 headgasket replacement or for that matter a set of new heads because they cracked under all the heat and stress they were under. Let us know if it turns out to be something else if the Thermogasket stuff doesnt work out.

 

Thank you for the info. I always do use anti freeze but never considered the route that the water was using. No offense taken I am new to the north star motor and appreciate any feed back about it. I will let every one know how it works out with the thermogasket product. I will be running dex cool this time and nothing other than what it calls for

 

I used the thermogasket product about 4,000 miles ago. It stopped the smoke and overheating issue but for some reason i was still building pressure in the system. At about 208 degrees it would push antifreeze past the cap while driving the car but at idle it would be fine. These motors in my opinion run too hot the thermostat dont open fully till about 218 i believe and the fans dont come on at high speed until 224. I ended up eliminating the fans from the ecm and put my own fan relay with temp sensor that is adjustable .

 

part of the reason for this is because of the High compression. Ive heard of some people trying to use or make a 180* T-stat to keep the temp down but not sure how well it work out for them. I think if there was a better way to keep these engines cooler they would not be so prone to having as many overheating issues. Most of us who have this engine dont use it for its intended purpose and because of that it has its issues. These were more or less a high performance engine that needs its excercise and it doesnt get that with daily drives and i think that hurts it over a course of time. i ususally take my cady out on the highway once a week and let her run and notice she stays cooler and runs smoother afterwards. Also if you dont use premium fuel like it recomends you may notice some issues too. i ran into a young kid who was using regular 87-89 octane and didnt know why he had check light for knock issues. the first question i asked was what fuel he was using and once i told him to start using premium he said he noticed it ran smoother. Although it cost more at the pump its better than having issues later from using lower octane fuels.

 

Can someone please tell me how to bleed the air out of my cooling system

 

the cooling system bleeds itself on the Northstar Cady's. but if you just let the car idle with the cap off for a little bit it will let out the bigger bubbles (carefull not to let the car get to warm other wise it will overflow.). but if the headgaskets are bad you will be beating a dead horse trying to bleed the system.

 

My purge line and the little nipple that it goes into were clogged with crap not allowing the water to flow through

 

Ok guys thanks for all the help. I found out it was just that water valve luckily. I added dexcool and a new thermostat and she's runnin like a champ.

 

Hi i am needing some advice on a 2001 deville.it has an overheating issue.we bought the car with 68,000 on it.drove it and began to overheat,so we took it to cadillac and they did the dye test and said it was a blown headgasket so we had them put a new one on. Drove it 300 miles and overheats again. Water pump,thermostat replaced ,twice, purge line is fine,no air bubbles in the line,they say. Still cant figure it out. Someone told me that if the catalytic gets hot and melts partially that it wont throw an engine code right awat but could cause blockage to the coolant system.should i check the back pressure or would that really have nothing to do with it? Also i did put a new radiator in it too. Any help would be appreciated as it is not going back to cadillac as i dont think they know anymore about it now than when they charged 5000 plus to fix it. Thanks, jeep lady