: what is considered normal coolant temperture for a north*?



limoguy
10-30-07, 06:13 PM
My 98 deville with 120k, runs from 196 on the highway & between 196-223 without the A/C on in traffic. Is this normal?

JimD
10-30-07, 07:16 PM
Based on my driving experience (approx. 190,000 miles on two different cars), my answer would be YES. You are seeing normal and expected temperatures under the conditions you mentioned.

Ranger
10-30-07, 09:41 PM
My '97 Deville was the only digidash I had. I ran 205 (summer) to 215 (winter). Your temps still sound about normal. Cooling fans don't come on till 224.

limoguy
10-30-07, 10:19 PM
thanks guys

LCLCLC
11-01-07, 04:14 AM
Your car is running correctly.

Cadillacs are strange. Basically, they run cooler with the AC running.

With the AC running, the fan is turned on. With the fan on, it will maintain a 197degree theromostat level.

If you have it in 'Econ', this means the AC will not run. With the AC not running the fans are not on. Until the temp hits about 220degrees, then the fans turn on.

Therefore, a Cadillac will run cooler with the AC on.

limoguy
06-09-08, 08:53 PM
My fans dont seem like there running fast enough when a/c is on. Is this possible? I was driving with the hood in the partly open position to get more air in. Hot day, so i had A/C on, usually the coolant temp stays around 200. I saw it go up to 217. That cant be good, can it?

Ranger
06-09-08, 09:11 PM
205-215 is normal operating temperature. Nothing to get worried about.

limoguy
06-09-08, 09:22 PM
thanks ranger...Im better off not looking at the temperture gauge. I will change it to RPM mode!

Submariner409
06-10-08, 08:24 AM
limoguy......I just did another post on thermostats......your engine is set up so the thermostat begins to open at 188 and is fully open at 206. The engine is designed to run at 210 or so, all the time. The 18# pressure cap lets the coolant go to 264 before boilover. The fan(s), in normal engine cooling mode, come on at 222-224, slow, and go to fast at 236. One fan or two runs in slow when the HVAC system is set to use the a/c compressor for some function, whether cooling or defrosting. Fan(s) generally will not run at all above about 40-45 mph due to airflow through the engine compartment.
FWIW, the fans also go to fast at a transmission temp of 302. 302.

krimson_cardnal
06-10-08, 01:12 PM
limoguy......I just did another post on thermostats......your engine is set up so the thermostat begins to open at 188 and is fully open at 206. The engine is designed to run at 210 or so, all the time. The 18# pressure cap lets the coolant go to 264 before boilover. The fan(s), in normal engine cooling mode, come on at 222-224, slow, and go to fast at 236. One fan or two runs in slow when the HVAC system is set to use the a/c compressor for some function, whether cooling or defrosting. Fan(s) generally will not run at all above about 40-45 mph due to airflow through the engine compartment.
FWIW, the fans also go to fast at a transmission temp of 302. 302.

Thanks for the fan speed info. I recently took a look at the fans and noticed it didn't look like it was up to speed, now I understand why. K_C

Submariner409
06-10-08, 01:52 PM
Yeah......a fan in slow really looks like it is just loafing along. Not sure about your year's setup, but my '02 uses a set of fuses and relays, in the engine room box, to run the fan(s) in slow with a series hookup or in fast, parallel hookup. If you pull the relays, the contact diagram is on the bottom and you can figure out the various speed/hookup configurations.

One fan jumpered to high across the relay socket with a piece of 18 gauge copper wire will smoke the wire and the tips of your fingers. Ask me how I know........When a fan's in high, it roars !!

limoguy
06-11-08, 07:37 AM
What a jackass I am. The car was short 2 quarts of oil, made it run those higher coolant temps. I added the oil & she runs at 197 degrees with A/C on. Sorry for the confusion. Very happy it was a no brainer!!:bigroll:

Ranger
06-11-08, 09:47 AM
2 qts low will have absolutely no effect on the engine temps.

Submariner409
06-11-08, 12:11 PM
:yeah:............matter of fact, the "check oil" light doesn't come on until somewhere around 2 quarts low.

limoguy
06-11-08, 02:04 PM
2 qts low will have absolutely no effect on the engine temps.


Well.....Thats all I did to it.coolant Temps are now at 196 degrees with A/C on. It was 96 degrees outside yesterday. Before I added the oil the temps were going up and down from 197-219. Apparently, it made a difference. Im certainly not complaining.

Ranger
06-11-08, 08:09 PM
It was just a coincidence. Keep an eye on the temps.

limoguy
06-11-08, 10:27 PM
It was just a coincidence. Keep an eye on the temps.


Maybe it was a coincidence but seems unlikely. All I did was add the oilI always have the temps on my screen. I can see the difference right away. When I put the oil in, she is running cooler. 197 degreew with a/c on.
I will continue to watch it. She has 172k miles now.

tateos
06-17-08, 05:18 PM
My '97 was running at 231-232 degrees yesterday in traffic with the AC mostly off, and it was 112 degrees here in Phoenix. I was trying to keep the AC off to keep the temps as low as possible, but it seems like when the AC was on, the temps started to go lower, since the fans kicked in.

Submariner409
06-17-08, 05:30 PM
Yep, when you enable a ventilation mode which calls for A/C at least 1 fan runs in slow all the time and the rest of the fan sequencing is as normal.

Tateos, Have you ever heard both fans go to high speed at 234 degrees? Quite impressive.

tateos
06-17-08, 06:42 PM
I think I have heard the fans on high.

The loudest fans I have heard was on my '86 and '88 Merkur Xr4tis - when those fans were on, it sounded like a wind tunnel!

limoguy
06-19-08, 07:23 PM
My car seems to still be running good as far as temps go. 197-201 with A/C on. Those fans do wonders. I continue to watch the oil level as well. Im happy with those numbers.:cool2:

Rafterd
06-24-08, 07:40 PM
I know this horse is dead, but I don't have digital readout on my 98 STS. Normally with outside temp at 90 degres or less, my temp guage is at 12 o'clock position with a/c. If it gets to 95 or above, the guage goes to the 1 o'clock position, at which time I turn off the a/c and it cools back to the 12 o'clock position. Just had headgaskets done, with new radiator, waterpump, thermostat, hoses, and heater core. I think I am gun shy. Is the 1 o'clock position HOT? How about the 2002 STS. Are they better on headgasket problems? A friend has one with 58k for 10k. No dings or scratches.

Bill

Submariner409
06-24-08, 08:36 PM
Don't get paranoid.....let the a/c and fan systems do their jobs and you drive the car. Anywhere from 12:00 to 1:00 in the summer season is perfectly OK.

Yes, there was a head bolt redesign in 2000+. Whether that did away with the head lifting problem or not is still open for debate. If you have a car you like, drive it until something causes you to look for a replacement. There are a LOT of 2000+ Sevilles out there.

Rafterd
06-24-08, 09:28 PM
I sure do like my car. I also have a 12/12 waranty with the headgasket job. It has not lost so much as a drop of water since the repair. I'm just afraid of it.

Bill

Ranger
06-24-08, 09:52 PM
Do a search. I think JimD posted a picture of the gauge with temps added to it. Someone may have it stored and can post it or link it.

JimD
06-24-08, 11:05 PM
One o'clock is nowhere near a dangerous temperature. There are bells and whistles and dinging alarms to endure when the coolant temperature approaches the dangerous range.

Here are the measured coolant temperature numbers from my '98 Seville;
http://s70.photobucket.com/albums/i101/JimDphotobucket/?action=view&current=Smallertempguagewithnumbers.jpg

I would like to measure actual coolant temperature at the mark above 250 degrees. Perhaps someone will offer up a donor car (I am sure as hell not going to force the coolant temperature on my engine that high)?

Rafterd
06-25-08, 09:56 PM
By the pic, the 1 o'clock position is 235 and that is not to hot? I don't know if it will go past that mark or not, I turn off the a/c compressor for about 2 minutes and it goes right back to normal. If it was hot, then it would have boiled water and it has not. Next time I drive it I will see if it goes past 1 o'clock.

Bill

Submariner409
06-26-08, 09:50 AM
The later Northstars operate with an 18 psi pressure cap on the surge tank. Using a 50/50 mix of coolant (either kind) produces a boiling point of around 265 degrees F. The cooling fans come on at 223 don't even shift to high speed until 234. (One always runs in an a/c compressor run mode)

If your car boils at anything near 235 you have a pressure cap problem or blown head gasket (which does not "boil" the coolant, it overpressurizes the system so coolant blows out - but it's still darn hot......)