: overheating



Mago
08-12-05, 09:18 PM
What is the normal coolent tempature for a northstar engine
before the fans turn on? (cadillac 97)

R-Caddy
08-12-05, 09:24 PM
northstar :histeric: I think thermostat starts to open at about 198 degrees and the fan come on at about 220 :confused: I think... But the temperature gauge is going to show it quite hot :yup:

Vesicant
08-13-05, 11:59 AM
Moved.... from the Catera section...

Ranger
08-13-05, 12:56 PM
They seem to vary a bit but mine runs about 206 during the summer and 213 during the winter +/- a couple of degrees.

Eldyfig
08-13-05, 02:29 PM
Fans turn on when the temp reaches 225 or whenever the a/c is running.

Rick94STS
08-29-05, 10:19 AM
Is there a way to make the fans turn on earlier??

Ranger
08-29-05, 12:56 PM
Not that I am aware of unless you hot wire them to run all the time.

Rick94STS
08-29-05, 02:08 PM
Not that I am aware of unless you hot wire them to run all the time.

Yeah I thought of splicing in a toggle switch to ground and mounting it under the dash to turn on the fans when I want, not sure if I want to go that way, was hoping there was a more clean way of doing it.

thanks

Ranger
08-29-05, 06:17 PM
Why do you want to force them on? If the system is not operating as designed then I think you'd be far better off finding the problem and correcting it rather than crutching it.

kaps52
08-29-05, 11:05 PM
most gm fan switches/ecm turn on the fans around 230 plus you always want the engine to run at normal temps between 200- 230 for emissions reasons, also the engine parts expand if the temp does not reach normal temp premature engine wear could occur

VinnyT
08-30-05, 08:21 AM
I still think 200-220 is TOO hot. Engines like cooler temps. I used to work on Chevy 350's, Buick 3.8, even Audi 5 cylinders and they all benefited with lower temps. I've been debating changing the T-stat to 180. The coolant temp sensor will decide when the fans cut on. I'm looking for one of those now. One that will turn on at 195. I've know people to run 160 stats in cars, which is TOO low. I cannot see anything negative in running a 180 stat. Lower temps would probably help the head gasket issue as well. Just my $.02.:yup:

JimD
08-30-05, 09:31 AM
What is the normal coolent tempature for a northstar engine
before the fans turn on? (cadillac 97)

Normal coolant temp. for my '98 is approximately 200 degrees at idle with no air flow across the radiator. With A/C off, engine idle, no air flow, my fans come on (at low speed) at 220 degrees and shut off when temp. drops to 214 degrees. Just like the sytem was designed and built to do.

With any amount of air flow (vehicle moving > 15 MPH), the coolant temperature sits right at the wet thermostat operating point (again, approximately 200 degrees).

A 50/50 mix of water/ethelyne glycol at 15 PSI has a boiling point of 265 degrees. I don't have a problem with the coolant temp. reaching 220 degrees at idle in traffic. One of the benefits of running a little higher temp. is the vaporization of potentially nasty fluids in the crankcase oil supply, again, as designed.

144,000 trouble-free miles and counting.

Rick94STS
08-30-05, 05:58 PM
Why do you want to force them on? If the system is not operating as designed then I think you'd be far better off finding the problem and correcting it rather than crutching it.

I would like to have the option of turning them on at will, I am having no problems at all with my coolant system at this moment but the milege is at 135K right now and I am concerned with that so I would like to run it cooler in the summer months. I agree with others that 225 to 230 degrees is just "TOO HOT" for any engine to run no matter what it was designed to do, especially on a high milege vehicle.

I was told the LS1 motor in my Vette will run better at high temps, but that means more emission friendly better, not high performance long life better. With that said I have a 160 stat and fans programmed to turn on early which gives me that warm and fuzzy.

VinnyT - if you ever locate that temp sensor that will turn the fans on earlier for the N* please let me know

thanks

mcowden
08-30-05, 06:15 PM
I would like to have the option of turning them on at will, I am having no problems at all with my coolant system at this moment but the milege is at 135K right now and I am concerned with that so I would like to run it cooler in the summer months. I agree with others that 225 to 230 degrees is just "TOO HOT" for any engine to run no matter what it was designed to do, especially on a high milege vehicle.

I was told the LS1 motor in my Vette will run better at high temps, but that means more emission friendly better, not high performance long life better. With that said I have a 160 stat and fans programmed to turn on early which gives me that warm and fuzzy.

VinnyT - if you ever locate that temp sensor that will turn the fans on earlier for the N* please let me know

thanks


Not sure why you think you need to re-engineer something that works just fine for the vast majority of owners. Exactly why is 230 "too hot?" What damage or other negative effects do you think will happen? How do you refute the evidence that most of these cars never have any heat-related problems? Are you saying that if everybody put a lower temperature thermostat in their car that the engine would last longer for everyone?

Ranger
08-30-05, 08:01 PM
"I would like to have the option of turning them on at will, I am having no problems at all with my coolant system at this moment but the milege is at 135K right now and I am concerned with that so I would like to run it cooler in the summer months. I agree with others that 225 to 230 degrees is just "TOO HOT" for any engine to run no matter what it was designed to do, especially on a high milege vehicle."

Well, if it makes you feel better, go ahead. If that where true, how can you explain the many 200-300K Northstars that are running around with no problems? I really think you are worrying needlessly.

Eldyfig
08-30-05, 08:39 PM
Since I installed a new radiator about a year ago, my temps are consistently around 199-205. I don't think I have seen 225 or above since the new rad. I have seen about 213 while idling in the driveway. I keep the temp in the display most of the time. It is either that or the voltage. If my temps start hitting 230, I would be wondering what is going on.

kaps52
08-31-05, 12:16 AM
if you do research like alldata or mitchell on demand the reading on the dash and ect engine coolant temp senson for the ecm is 5 to 20 degrees lower the car was and most other modern car are designed to run aprox 220 that is the best for oil flow and cyulinder lube metals expand and clearances change 220 would have the least wear

Eldyfig
08-31-05, 07:19 AM
As far as everyone here is concerned, we are all talking about what the temp on the display is. The fans in these North*s come on at 225, read from the display or in the OBD.

I would be interested in reading that info that you mentioned. I don't have an account with Alldata. Do you have a link or can you copy and paste that info for all to see?

Rick94STS
08-31-05, 08:00 PM
Since I installed a new radiator about a year ago, my temps are consistently around 199-205. I don't think I have seen 225 or above since the new rad. I have seen about 213 while idling in the driveway. I keep the temp in the display most of the time. It is either that or the voltage. If my temps start hitting 230, I would be wondering what is going on.

THIS IS WHAT I AM TALKING ABOUT! Why are some N*'s running at 225 - 230 and some like above with a new radiator are running 199-213??

I am not trying to re-engineer what Caddy spent millions to invent but is 225-230 supposed to be a "normal" temp? Can someone back this up with proof? Or is it just a whole lot of people driving around with old clogged up radiators running HOT and thinking its normal?

PS: the plastic that surronds my heater blower motor on my firewall has many cracks in it, you know why? Its called heat damage. I filled them in with epoxy when I started smelling fumes in the cabin! I would consider that a big problem!

mcowden
09-01-05, 02:20 AM
THIS IS WHAT I AM TALKING ABOUT! Why are some N*'s running at 225 - 230 and some like above with a new radiator are running 199-213??

I am not trying to re-engineer what Caddy spent millions to invent but is 225-230 supposed to be a "normal" temp? Can someone back this up with proof? Or is it just a whole lot of people driving around with old clogged up radiators running HOT and thinking its normal?

PS: the plastic that surronds my heater blower motor on my firewall has many cracks in it, you know why? Its called heat damage. I filled them in with epoxy when I started smelling fumes in the cabin! I would consider that a big problem!

You are not taking into account under what conditions they are running hot. Maybe they're in stop-and-go traffic on a 95 degree day with the A/C running. If they're on the highway and it's running 225, I would replace the thermostat with a new OEM-temperature unit, check out the water pump, and get the radiator checked. Putting a 180 stat in there is breaking what wasn't broke. It was designed to run at those temperatures or there would be lights and bells telling you to stop. The fans don't kick on low speed until 225. Isn't that proof enough that 225 is a normal temperature? Obviously, the engineers don't think that's a problem, and the vast majority of Northstar owners never have any heat-related problems. Since the system was designed, tested, and validated to run at those temperatures, I still don't see why you are intent on convincing everyone that a lower temperature thermostat is what they need. To my knowledge, nobody here has ever had overheating damage that was caused by anything other than a cooling system failure. I'm very interested to hear how many people have had the plastic cracking problem you mentioned. That's the first time I've ever heard of that one. If everything is operating normally with the thermostat specified by the engineers, the engine will run just fine. If there is a problem, fix it, but I haven't seen or heard of a problem with the OEM thermostat temperature yet. Leave the engineering decisions to engineers. Lowering the operating temperature can have gas mileage and possibly lubrication consequences and, to me, that's more risky than letting the thing run the way they designed it to run.

I have a '96 SLS with the original radiator. I've replaced the water pump, the cap, the thermostat (AC-Delco OEM) and the water pump cover seal. I used the recommended 50/50 mix of Dex-Cool and distilled water and the recommended supplement (doubled per Rob's recommendation). My car runs at 199-206 usually. On very hot days or driving in city traffic with lots of idling and A/C running, it will run 215+ and sometimes climb up to 225+. I don't worry about it one bit and I've got 96,xxx miles and counting.

1fastSTS
09-07-05, 12:08 AM
ill answer the question for you!.
my 99 seville should never see 225- or 230 degrees.i mean i never had any car where i saw anything over 200 degrees for the coolant temp. once it starts going past 205 and increasing id be a little concerned. my Seville STS sees anywhere from 195- 203 in stop and go traffic right now in 80-95degree days. But if you were overheating the coolant hot or whatever warning light for the engine overheating , should turn on also!
id get it checked out befoe you crack the block on this sucker. which can happen
usually factory cars are set at 195 for fan turn on also.

these cars do run pretty hot though ive noticed, oppossed to the Buick Grand national motors i am used to, and i know exactly what you mean about the 180 T stats. i have them in my Gn now.
as far as doing this to the caddy, its all computerized and set to specs from the factory, changing anything would throw off the whole balance of the car. and theres no chips or any custom computer program for changing the fan to turn on at 180 like the availabilty we have for our small blocks and other performance cars. unfortunatly.