: Northstar Heating Up



BLAC-ON-BLAC-LAC
06-24-03, 12:12 AM
I am having problems with my 96 caddy deville. It keeps heating up on me. First I changed my fan relays cause they weren't turning fast enough,(it helped) then I changed the water pump, and its still heating up. I took the thermostat off too. Right now I am flushing the radiator, lets see if that helps. Can anyone help me out with any pointers? What are the symptoms of head bolts unscrewing themselves? could that be the problem? The car at idle wont heat up, it stays around 220F, I can leave it on idling with no problems, but if I start driving it it will heat up, and spill the water through the top overfill hose.

elwesso
06-24-03, 01:09 AM
You may have some clogged areas somewhere..... most likely a cause of insuffecient cooling system maintenance...... I dont know how well those prestone radiator cleaner things work, but it may be worth a shot.....

BLAC-ON-BLAC-LAC
06-24-03, 01:19 AM
I hope it works. Do you know the symptoms of the bolts coming out issue.

elwesso
06-24-03, 01:26 AM
The head gasket failing..... white smoke from tailpipe, while foamy oil, coolant dripping from the side of the block......

what your describing is not the head bolts pulling.....

BLAC-ON-BLAC-LAC
06-24-03, 01:35 AM
ohh man, I am reliefed! Do you think it might be the radiator? I think it might be. I hope. Can you tell me which way the water should flow? From the bottom to the top? from the top to the bottom?

BLAC-ON-BLAC-LAC
06-25-03, 12:15 AM
ok I just finished with the flush procedure. I put the flush, ran it a while, emptied the flush, then washed out the radiator (put waterhose at reservoir let circulate through the radiator with the butterfly off. Next Im gonna fill back up and try it. (fingers crossed). ANYWAY. My question is, should I put another bottle of the bars copper flakes in it? I had put some before, but it has then drained about 10 times with all the overheating and changing of things, does it wear off?

elwesso
06-25-03, 12:17 AM
I dont know which way it flows for sure..... but whichever end is closer to the water pump you can assume that HOT water flows through there and then out the other side...... For instance, on my car, it starts out the passenger side top and ends up bottom drivers side....

also, whichever side the mechanical fan is on (unless there are 2 on the northstar, i dont know), you can assume that hot water flows in to that side.....

Dont take my word as fact, someone else will chime in that knows the northstars cooling system better than me!

BLAC-ON-BLAC-LAC
06-25-03, 12:48 AM
you think I should put the bars copper flakes in?

elwesso
06-25-03, 01:24 PM
I have heard that you HAVE to put in the coolant supplement stuff into the northstars cooling system..... I dont know for sure (it sounds like an accident waiting to happen-- an additive that stops leaks, and could potentially clog something!)

elwesso
06-26-03, 12:44 AM
Also, about your flush procedure, I WOULD DRAIN IT RIGHT NOW (well not NOW, but as soon as you can), and fill it with distilled water..... the bottled stuff you get from walmart (not more than $1/gal)...... There is too many minerals in your tap water, and can actually cause MORE deposits....

Here is the flush procedure I got for my Q45

1. Drain radiator
2. Fill radiator with distilled water
3. Run to operating temp (at least enough to open tstat)
4. Let cool down
5. Repeat until clear water flows out
6. On the final refill, fill with appropriate amount of antifreeze....

I dont know about what mixture you should use, but for me the mixture is 70% water, 1 bottle of redline water wetter, and the rest AF......

SoundAdvantage
06-26-03, 01:20 AM
Hello, I hope you didn't take the Thermostat out and leave it out because that would cause it to overheat. Make sure you go to Napa and buy the BEST thermostat they offer, you can get different heat ranges so your engine will run cooler, and i wouldn't add any stop leak additives of any kind either, unless recommended by your Cadillac Dealer! and lastly your engine Timing can cause it to run hot, try a different heat range on your new thermostat 1st.

elwesso
06-26-03, 04:19 PM
Use a 200 tstat..... Anything less will cause it to run overly rich......

Cadillac recommends you use the coolant stop leaks things..... I wont use them, but to each their own.....

I would change the tstat anyway...... Its about a $10 part, and it can save your engine (especially since it is very sensitive to overheating!)

eehoepp
06-27-03, 12:38 AM
I have a 94 STS. FWIW, this was my experience...

Last December I had the following symptoms: 1) Check coolant level message kept showing up 2) Started overheating only while driving. It would idle at normal temp for an hour, but start overheating when driving a mile or more 3) Kept losing coolant. No external coolant leaks, no white exhaust smoke, just boiling out the overflow.

I did the repair myself. Pulled head bolt was the culprit. Head gasket blew from the combustion chamber to the water jacket right at the loose bolt. I did not have any coolant in the oil. I repaired ALL of the head bolt holes with the Time-Sert kit. It was expensive, but it was the right way to do it. It would have been ridiculously expensive to have a dealer fix it.

I have had no trouble with the engine since the repair. I drive the car pretty hard. The tach hits the redline on a daily basis. Still love the Northstar.

BLAC-ON-BLAC-LAC
06-27-03, 12:43 AM
hey, eehoepp, when you did the time sert procedure did you take out the engine, or did you do it under the hood?

eehoepp
06-27-03, 12:53 AM
Whoops, forgot some things...

The Northstar engine is a reverse-flow coolant design. Coolant flows from the heads down into the block, then through the long rad hose to the right (passenger) end of the rad. Right to left through the rad and then back to the water pump. In general, hot coolant flows into the rad via the higher hose neck, and cool coolant flows from the lower hose neck to the water pump.

The cooling system sealer pellets are strongly recommended/required in the Northstar engine. The effectiveness of them is lost when you change coolant or flush the system, as most of the flakes/fibers exit with the coolant. When I bought the pellets, the part counter guy said "you can use one or two (pellets), but if you put in three, I guarantee you'll clog the heater core".

The thermostat is more expensive than a standard stat because of the reverse flow design. But they are still cheap compared to the alternative.

elwesso
06-27-03, 12:37 PM
You have to take out the engine to repair the head bolts, and is not a job for the average DIYer with average tools..... You basically need the car on a lift......

One of the downsides to having the engine in sideways rather than correctly!

eehoepp
06-27-03, 06:28 PM
You have to take out the engine to repair the head bolts, and is not a job for the average DIYer with average tools.....

I'll take that as a compliment. It CAN be done by an experienced and/or careful DIYer.


You basically need the car on a lift......


Not really... (see the attachment) I used an engine hoist to lift the car body off the powertrain.


One of the downsides to having the engine in sideways rather than correctly!

And yet, one of the advantages, too - the powertrain comes out the bottom in one neat package.

If you are going to attempt this, 1) get a factory service manual (eBay or helminc.com to buy new) and 2) let me know - I've got a complete TimeSert kit that I'm done with & wouldn't object to selling & I have a design for a powertrain dolly that worked well for me.

The factory service manual recommends leaving the struts, hubs, etc in the car. I think it was easier removing them with the powertrain. When putting the TimeSerts in, if you are careful with keeping the chips under control, you don't have to separate the engine from the trans. If you let chips stray into the oil drainback holes, you need to separate the engine from the trans to get the oil pan off for cleaning out.

I'm here if you've got other questions, but I sometimes don't get to check the board for a week or more.

Good Luck.

Mad'lac
06-27-03, 08:01 PM
Damn eehoepp!!! I would love to have you as a neighbor. Its from guys like you I learn a bit about DIY. I used to be afraid to touch the gears in the rearend but my gf's bro-in-law showed me how to do some of these things. Now I laugh at my buddies who call me to help them swap out the gears. I got one of my friends to rebuild my tranny for the work I done to his truck's grs.

elwesso
06-28-03, 12:31 AM
When I said the AVERAGE DIYer, that implys the guys that will do all the maintenance stuff; stuff thats easy, doesnt take up much time, and keeps them occupoed..... They do not have all the tools and an engine hoist to do major stuff..... You, in my book, would be a "seasoned" or an "advanced" DIYer.....

And judging by his previous posts, it doesnt seem <to me> that black on black lac is up to the challenge..... It would a shame to get it partially apart and then have to get it fixed halfway through!!

eehoepp
06-28-03, 02:50 PM
It would a shame to get it partially apart and then have to get it fixed halfway through!!

Agreed. This is not a repair to be tackled by one who only has done oil changes and spark plugs. It is time consuming - it took me about 2 months of evenings and weekends, although that was aggravated by working in the great outdoors/in an unheated garage through February & March (note the snow in the photo).

Taking on a repair like this requires the wrencher to be very committed (in every sense of the word) and have alternate transportation for however long the repair takes. It also requires some commitment from the spouse/gf if you still want to have a relationship at the end of it all.

IMHO, if a DIYer has been able to successfully rebuild an alternator or starter motor by following the directions in a repair kit, they are capable of a repair like this. We all get started somewhere and if we don't challenge ourselves, we'll never get better. DIYers certainly don't get any pofessional training, so we have to learn by doing what we may not be 100% sure of. The DIYer has to be determined to do the whole job, whatever that entails.

FWIW, I consider myself to be an insanely serious DIYer. I've long held the view that I don't save much money by doing all repairs myself, because I end up spending some of that on tools. The Northstar head gasket repair was the exception - I know I saved thousands doing it myself (but I didn't have the funds to pay someone to do it for me anyway).

A DIYer with a decent socket set and selection of wrenches would probably have to shell out a couple hundred bucks for some bearing pullers and torque wrenches. An engine crane can be rented relatively cheap. The factory service manual is a must. Aside from these, I don't recall having to use any exotic tools for the repair.

My $0.02

BLAC-ON-BLAC-LAC
06-29-03, 03:03 AM
hey I wanted to know If it was possible to do it or not. I understand this is a hard task, but anyways there is still otherthing I got to check before.
I found out that the heater core was bypassed. I guess the owner before me did this. He unplugged the two hoses (inner- outer) and put a copper u bend water line and put the hoses to it. So its just a u right now. Could this cause it to heat up? How can I get to the heater core? I am gonna try to do this tomorrow. I think Im gonna change the heater core and put thermostat on tomorrow.

Thanx eehoep. People can learn alot with guys like you. I agree people can do alot of things if they put their mind to it. If I ever need to do it (timesert) hope you can help.

vanaisa
06-29-03, 06:50 AM
---I found out that the heater core was bypassed. I guess the owner before me did this. He unplugged the two hoses (inner- outer) and put a copper u bend water line and put the hoses to it. So its just a u right now. Could this cause it to heat up? How can I get to the heater core?---
IMHO heater core must be part of cooling system and can not be elimnated!!!

BLAC-ON-BLAC-LAC
06-29-03, 12:42 PM
ok so it cant be eliminated., Does anyone know how to get to it?

elwesso
06-29-03, 03:04 PM
There should be some plug ins going right into the firewall right next to the U bend thing you were referring to...... There should be some open ends there.....

But, it seems the owner wouldnt bypass the heatercore unless he had to...... which leads me to believe that it is clogged, or is defective in some other way...... I know there are some procedures to replace the heater core floating around here...... on this car, it isnt too hard (i dont think, maybe im confused)......

zonie77
09-25-03, 04:03 PM
To eehoepp:
I would be interested in the timesert kit if you still have it. Let me know.

zonie77
09-25-03, 04:08 PM
Bypassing the heater core is common if you live in a warm area.
While it is part of the cooling system it only adds cooling if it is being used (air flowing over it). If the heat vents are closed it really doesn't add cooling.
The previous owner didn't want to pay or do the work to replace it.
Your post is a few months old...Did you replace it?
What is status on the overheating problem?

ljklaiber
09-25-03, 06:34 PM
Agreed. This is not a repair to be tackled by one who only has done oil changes and spark plugs. It is time consuming - it took me about 2 months of evenings and weekends, although that was aggravated by working in the great outdoors/in an unheated garage through February & March (note the snow in the photo).

Taking on a repair like this requires the wrencher to be very committed (in every sense of the word) and have alternate transportation for however long the repair takes. It also requires some commitment from the spouse/gf if you still want to have a relationship at the end of it all.

IMHO, if a DIYer has been able to successfully rebuild an alternator or starter motor by following the directions in a repair kit, they are capable of a repair like this. We all get started somewhere and if we don't challenge ourselves, we'll never get better. DIYers certainly don't get any pofessional training, so we have to learn by doing what we may not be 100% sure of. The DIYer has to be determined to do the whole job, whatever that entails.

FWIW, I consider myself to be an insanely serious DIYer. I've long held

the view that I don't save much money by doing all repairs myself, because I end up spending some of that on tools. The Northstar head gasket repair was the exception - I know I saved thousands doing it myself (but I didn't have the funds to pay someone to do it for me anyway).

A DIYer with a decent socket set and selection of wrenches would probably have to shell out a couple hundred bucks for some bearing pullers and torque wrenches. An engine crane can be rented relatively cheap. The factory service manual is a must. Aside from these, I don't recall having to use any exotic tools for the repair.

My $0.02
In my day , you would have been called a 'greaser'...the guy that has a girlfriend who holds wrenches and the trouble light. I am damn proud of guys like you. Probably , because that is how I grew up.....fixin it
myself.

I have been married for thirty6 years to the gal who passed the wrenches, and held the light. LOL

botboy
09-26-03, 12:57 AM
To eehoepp:
I would be interested in the timesert kit if you still have it. Let me know.

I'll buy it if he doesn't. botboy60@hotmail.com

zonie77
09-26-03, 03:53 AM
I'll put up my email for eehoepp or anyone else with info on head gasket replacement:

gastoll@yahoo.com

My brother has a 94 STS, 135,000. Compression test showed (first compression stroke) 120's except for 45 on cyl 7. Looks like we will be replacing gaskets and checking heads!

Any firsthand advice will be appreciated.

Timeserts and new bolts are a given after reading the posts.

Loud 93 STS
09-26-03, 12:52 PM
I have a 93 STS and I am also having a slight heating problem. On the thermostat, what is an original from Cadillac rated at and how low should I go on the temp? I was thinking a 180-185. I have heard a lot about the head bolts and I know thats not the problem because I have a good friend who is a GM mechanic and we have checked that out. Not sure what it is, may be some kind of wiring problem. If anyone has any suggestions they would greatly be appreciated.