Wow, It's Hot...

[JasonA]

Got in the car in the parking lot at work yesterday afternoon at about 4:30 and the temp said 112*F. Whew. Even after the 30 minute drive home, the reading was steady on 106*F. Engine temperatures averaged between 194-201, although I won't pretend to have the traffic that Scotty has.

Backed into the garage at about 5:00. This morning when I went to leave at a quarter of seven, the coolant temperature was still in the 110s, and the outside temperature was already in the low 80s. Another hot'un coming up!

[KHE]

The heat and humidity finally left Michigan last night. It was 57 degrees this morning with a high of 75-78 forcasted for today. Last week, it was in the low 90s with high humidity...

[Marika]

Last night as I was driving home, I noticed that my caddy said it was 103F outside, and that's here in New Jersey.

I've got no AC in the car but I was doing ok leaving the ECON on high and keeping the windows closed. It didn't get hot at all inside the car. Apparently, they are well insulated.

[JasonA]

I've got no AC in the car but I was doing ok leaving the ECON on high and keeping the windows closed. It didn't get hot at all inside the car. Apparently, they are well insulated.

I had mine on 60*F, on recirc, with fan on high, and it was just barely cool enough. I checked the service manual and the A/C vent discharge temperature in temperatures of 100*F with moderate-high humitidy were above 80*F. The system is working as designed (having never been charged since new), but it was still just barely cool enough for me.

[Scotty]

I had a few scares on Tuesday... I was in a funeral procession being escorted by a police motorcade at about 65 mph, and the outside temp hit 98, so I decided to take a look at my coolant temp, it was ranging from 217 to 222 with the AC on

Needless to say it got my attention as it was unusually high. On the way back, the temps were better but still higher than what I considered normal say 205 to 212 at highway speeds..... I was running up to 212 to 217 at highway speeds which to me is higher than 'normal'... Does this sound higher than normal with outide temp in excess of 95? I am changing my thermostat today....

My AC was freezing us out of the car by the way....

PS, the funeral cars were Caddy's with NS's and they idled the entire time at the cemetery so that kind of calmed my nerves (their temp was about half way, I had to look! ) The funeral car driver said he had a problem last week, his thermostat went bad and the temp went all the way up....

[adallak]

I replaced my stat with 180 one (thanks, Mike ) and at highway speeds I have steady 186. I hope it keeps my tranny cooler which is my main concern now. I never use AC, the passanget side windows are down halfway and it's fine for spirited country driving.

[Poobah]

Southern California has been a little cooler than normal until the last week or so. The past few days have been in the high 90's (about normal) but partly cloudy and very himid (very unusual). Very uncomfortable in the middle of the day.

[STS]

Just a quick question, I have a 97 STS and it has an analog temp gauge that runs pretty much in the center of the scale. Can I read out the temperature on the digital display somehow? This may be really easy but I have not messed around with it to know how. Thanks in advance.

[ted tcb]

I had a few scares on Tuesday... I was in a funeral procession being escorted by a police motorcade at about 65 mph, and the outside temp hit 98, so I decided to take a look at my coolant temp, it was ranging from 217 to 222 with the AC on

Needless to say it got my attention as it was unusually high. On the way back, the temps were better but still higher than what I considered normal say 205 to 212 at highway speeds..... I was running up to 212 to 217 at highway speeds which to me is higher than 'normal'... Does this sound higher than normal with outide temp in excess of 95? I am changing my thermostat today....

My AC was freezing us out of the car by the way....

PS, the funeral cars were Caddy's with NS's and they idled the entire time at the cemetery so that kind of calmed my nerves (their temp was about half way, I had to look! ) The funeral car driver said he had a problem last week, his thermostat went bad and the temp went all the way up....

Like someone else has said in the past, is it that our cars run too hot or do we have too much info with the DIC?

Last week, the ambient temp was 98f, and I was consistantly around 203f with the ac on at 65f, low auto. As soon as I hit city traffic, the temp went up to around 221f, and scared the heck out of me.

I turned the ac off and opened the windows and roof, but the running temp stayed at 221f ... the entire time, my needle just stayed at the halfway mark ... I sometimes wonder if the DIC temp just makes me nervous ... 98f outside, stop and go with the ac on, the car is probably just running at the upper end of the acceptable design parameters .... my coolant and tablets only have 3k since the last change, and my typical range is 196f to 201f .... its just too damm hot outside to maintain that range.

[Scotty]

Ted, your temps sound good very good I might add. Mine ran 222 to 226 at 65 MPH, with ram air through the radiator, very unusual if you ask me, normally with ram air temps drop down to 205, so this had my heart racing...

[Bob D]

Where have you guys been?? Don't you remember posts on N* temperatures? 225 degrees is JUST FINE!! 230-235 is NO PROBLEM!! This engine is designed to run at these temperatures, where the fans don't even come on until 225. Remember, with properly maintained 50/50 cooling system and a good 16 psi cap, coolant doesn't even boil until 265 degrees!!! You really don't even need to get concerned until it breaks 245 degrees and holds up there.

Example: It's been >100 degrees here in Northern Ca for over 2 weeks now. I drive that STS at 70mph up some pretty steep grades. WITH THE A/C ON!! I see the temps climb from 205-215 to 225-235 and hold. Big deal. Been doing this for years.

Jeeezzz..relax turn ion the a/c and enjoy the ride. Read the archives if you don't believe me...

[ted tcb]

Bob, hence my point on the analog gauge versus the DIC reading.

You glance at the needle, see it in the middle, and smile.

You glance at the DIC, see the numbers steadily climb one at a time, and freak out.

Your brain tells you its well within the acceptable range, but your heart races, saying "What The ***k"

[Ranger]

Hey Mike,

I recall just recently someone on cadillacforums mentioning that he used "Water Wetter" in the cooling system and claimes that it lowered his coolant temps. No idea what this stuff is, though I suspect it is just a softening agent, or if it really works but I would not think it can hurt anything if you want to give it a try.

[Bob D]

Hey Mike,

I recall just recently someone on cadillacforums mentioning that he used "Water Wetter" in the cooling system and claimes that it lowered his coolant temps. No idea what this stuff is, though I suspect it is just a softening agent, or if it really works but I would not think it can hurt anything if you want to give it a try.

Sorry.no Mike here but I've done my homework..Water wetter is a waste of money unless you are running a 100% H2o cooling system (like Nascar). It slightly changes the surface tension of water only, which in theory will raise the heat transfer ability a bit...

[Bob D]

Bob, hence my point on the analog gauge versus the DIC reading.

You glance at the needle, see it in the middle, and smile.

You glance at the DIC, see the numbers steadily climb one at a time, and freak out.

Your brain tells you its well within the acceptable range, but your heart races, saying "What The ***k"

I swear...some of these guys with the digital readout remind me of a bunch of lol's (little old ladies) LOL!!

"Oh my...It's 220 degrees!...Goodness gracious Mabel, it's 225!!! What will we do???!!

That's why the analong guages are dampened...to keep blood pressue down.

[KevinW]

I had mine on 60*F, on recirc, with fan on high, and it was just barely cool enough.  I checked the service manual and the A/C vent discharge temperature in temperatures of 100*F with moderate-high humitidy were above 80*F.  The system is working as designed (having never been charged since new), but it was still just barely cool enough for me. 

I would not make that conclusion because the test conditions are different. The vent discharge temperature suggested in the manual assumes a 10 minute period of running at idle, starting from a moderately heat-soaked condition. If you were cruising at 60+ mph for 10 minutes and could not achieve better than 80 F vent temperature (100 F ambient), then something is definitely wrong! I would estimate that 46 F should be attainable at the end of this period. Note that running in recirculate mode reduces the load on the system, especially in conditions of high humidity.

[KevinW]

Ted, your temps sound good very good I might add.  Mine ran 222 to 226 at 65 MPH, with ram air through the radiator, very unusual if you ask me, normally with ram air temps drop down to 205, so this had my heart racing...

Remember that your old observations were made when the A/C was not working! Improved A/C performance will increase the air temperature at the radiator.

Also, the hotter the radiator runs, the more efficient it becomes since the heat rejection rate is proportional to the temperature differential (relative to ambient).

[JasonA]

If you were cruising at 60+ mph for 10 minutes and could not achieve better than 80 F vent temperature (100 F ambient), then something is definitely wrong!

I agree, and I wish I could run at 60+ mph. Traffic at rush hour (here, about 4pm) is heavy, but it moves. Average speed on the surface streets is probably 35 mph. Many stoplights to run through.

Without recirc, it doesn't cut it. With recirc, it's pretty good. It's as cool after 5 minutes of driving as it ever gets. I can feel a slight increase in vent temperature as I sit at a light, and then once moving again, I can feel it drop again. I believe it's working normally, but maybe next summer I'll have the system checked. I only have to run recirc when it's 95 and humid outside (or above). Otherwise, it's fine.

[JasonA]

Just a quick question, I have a 97 STS and it has an analog temp gauge that runs pretty much in the center of the scale. Can I read out the temperature on the digital display somehow? This may be really easy but I have not messed around with it to know how. Thanks in advance.

Yes, you can show the digital temperature. Click here for that thread:

http://caddyinfo.ipbhost.com/index.php?showtopic=179

[Marika]

Where have you guys been?? Don't you remember posts on N* temperatures? 225 degrees is JUST FINE!! 230-235 is NO PROBLEM!! This engine is designed to run at these temperatures, where the fans don't even come on until 225. Remember, with properly maintained 50/50 cooling system and a good 16 psi cap, coolant doesn't even boil until 265 degrees!!! You really don't even need to get concerned until it breaks 245 degrees and holds up there.

Example: It's been >100 degrees here in Northern Ca for over 2 weeks now. I drive that STS at 70mph up some pretty steep grades. WITH THE A/C ON!! I see the temps climb from 205-215 to 225-235 and hold. Big deal. Been doing this for years.

Jeeezzz..relax turn ion the a/c and enjoy the ride. Read the archives if you don't believe me...

The fan on my 4.9 doesn't come on until 223F. But once it's on, the temps are driven down very fast back to 203 where the fan turns off.

[Scotty]

Where have you guys been?? Don't you remember posts on N* temperatures? 225 degrees is JUST FINE!! 230-235 is NO PROBLEM!! This engine is designed to run at these temperatures, where the fans don't even come on until 225. Remember, with properly maintained 50/50 cooling system and a good 16 psi cap, coolant doesn't even boil until 265 degrees!!! You really don't even need to get concerned until it breaks 245 degrees and holds up there.

Example: It's been >100 degrees here in Northern Ca for over 2 weeks now. I drive that STS at 70mph up some pretty steep grades. WITH THE A/C ON!! I see the temps climb from 205-215 to 225-235 and hold. Big deal. Been doing this for years.

Jeeezzz..relax turn ion the a/c and enjoy the ride. Read the archives if you don't believe me...

I know Bob you are right! It was just the sudden CHANGE in temps at highway speed that prompted me to get nervous.. As I noted, typically at 65 my temps drop to 205, yesterday they were 217 to 222, so that was the change that got my attention. BUT it was 98 degrees and humid....

[Scotty]

Hey Mike,

I recall just recently someone on cadillacforums mentioning that he used "Water Wetter" in the cooling system and claimes that it lowered his coolant temps. No idea what this stuff is, though I suspect it is just a softening agent, or if it really works but I would not think it can hurt anything if you want to give it a try.

Funny I asked my radiator shop about it. But.... then the question comes up as to whether or not its compatible with Dexcool, and if it were that good at dissapating heat, wouldn't Dexcool contain it already...

I might try it however for the hell of it...

[Scotty]

Bob, hence my point on the analog gauge versus the DIC reading.

You glance at the needle, see it in the middle, and smile.

You glance at the DIC, see the numbers steadily climb one at a time, and freak out.

Your brain tells you its well within the acceptable range, but your heart races, saying "What The ***k"

I swear...some of these guys with the digital readout remind me of a bunch of lol's (little old ladies) LOL!!

"Oh my...It's 220 degrees!...Goodness gracious Mabel, it's 225!!! What will we do???!!

That's why the analong guages are dampened...to keep blood pressue down.

Thats me a LOL....

[Scotty]

Ted, your temps sound good very good I might add.   Mine ran 222 to 226 at 65 MPH, with ram air through the radiator, very unusual if you ask me, normally with ram air temps drop down to 205, so this had my heart racing...

Remember that your old observations were made when the A/C was not working! Improved A/C performance will increase the air temperature at the radiator.

Also, the hotter the radiator runs, the more efficient it becomes since the heat rejection rate is proportional to the temperature differential (relative to ambient).

Thanks Kevin

[Matt]

I have to say that the cooling system on my car is " one thing " I have had no problems with. ( untill now that I said that and jinxed it ) We know its been very hot and in traffic with the AC on full only one time did the temps get up to 225. Then the fans come on and the temps jump right down just fine. I admit now that the electrical problems are all fixed all I do is watch the engine temps. That is something that is super important to me. I am really trying to take care of this Great Engine that Scotty found for me. I may be silly but i just changed the oil again only after 800 miles. I will do the coolent again in October.