: Coolant Temp



97d'elegance
04-12-04, 08:48 PM
:crying2: Okay .. I know I have posted before asking about safe temps for my 97 deville but I have to ask again. Yesterday I drove to my parents house for Easter .. left around 10am but it was already warm and humid and the A/C was on AUTO and 71 as usual. It was a little more than 80 degrees outside and very humid. I was moving along at around 75 or so and I decided to speed up ... I nailed it and was going about 97 when I noticed the coolant temp raise steadily from 206 up to 233 ... this happened in about 20 seconds time. I slowed down a lot and it went back down to around 217 and hung there most of the remaining trip. I drove about 60 miles one way to my parents. I didn't go over 75 or so after that happened and was scared it was developing a problem. There was quite a bit of stop and go traffic (which I drive in on a daily basis). I have driven 97 and much faster many times before and never saw the temp get close to that. Last evening when I left for the trip home it was about the same temperature outside and still humid. The temp ran around 217 again for a lot of the trip .. I was in stop and go again and it spiked up to 230 this time ... I was only going around 60mph this time. It then went back down to around 212 until I got home. Traffic wasn't as heavy this time and I was moving most of the time. The coolant level is normal and the oil is full. It was hot again this afternoon and I took my regular trip down I-4 in stop and go to and from work. It never went about 206 today. I do NOT understand this car. I know I seem to worry a lot about this but I am totally paranoid that it will run hot and I will blow a headgasket. Is this normal? What signs should I look for before stopping (other than the warning lights). I guess what I want to know is what is the highest temp I can drive at before I pull over and idle to cool down? Thanks again Everyone!! :banghead:

Anthony Cipriano
04-12-04, 09:24 PM
:crying2: Okay .. I know I have posted before asking about safe temps for my 97 deville but I have to ask again. Yesterday I drove to my parents house for Easter .. left around 10am but it was already warm and humid and the A/C was on AUTO and 71 as usual. It was a little more than 80 degrees outside and very humid. I was moving along at around 75 or so and I decided to speed up ... I nailed it and was going about 97 when I noticed the coolant temp raise steadily from 206 up to 233 ... this happened in about 20 seconds time. I slowed down a lot and it went back down to around 217 and hung there most of the remaining trip. I drove about 60 miles one way to my parents. I didn't go over 75 or so after that happened and was scared it was developing a problem. There was quite a bit of stop and go traffic (which I drive in on a daily basis). I have driven 97 and much faster many times before and never saw the temp get close to that. Last evening when I left for the trip home it was about the same temperature outside and still humid. The temp ran around 217 again for a lot of the trip .. I was in stop and go again and it spiked up to 230 this time ... I was only going around 60mph this time. It then went back down to around 212 until I got home. Traffic wasn't as heavy this time and I was moving most of the time. The coolant level is normal and the oil is full. It was hot again this afternoon and I took my regular trip down I-4 in stop and go to and from work. It never went about 206 today. I do NOT understand this car. I know I seem to worry a lot about this but I am totally paranoid that it will run hot and I will blow a headgasket. Is this normal? What signs should I look for before stopping (other than the warning lights). I guess what I want to know is what is the highest temp I can drive at before I pull over and idle to cool down? Thanks again Everyone!! :banghead:


Relax. Sounds perfectly normal. Spend more time watching the road instead of the coolant temperature. Better yet, turn off the DIC coolant temperature reading. There are plenty of automatic warnings if things should get too hot. Relax and let them work. The system can go to 245 or 250 degrees with no problems on a high demand, heavy load situation. It's designed to work that way. With a 15psi pressure cap and 50/50 coolant mixture in the system the system will not boil until 265 degrees. So you're a long ways from any sort of "over heat" situation. Besides, the Northstar engine has a "loss of coolant' limp home mode that will activate automatically long before you get any thing hot enough to damage a head gasket or anything. The loss of coolant limp home mode is so effective that it's been proven time and time again to run the engine for 50 miles at 50 MPH without any coolant in the system without any engine damage. So you (and your engine) are protected even in your worst nightmares of an overheat or something. It will allow you to drive to a safe place even with all the warnings and chimes going off without any risk of damage.

Really, forgot what used to be normal for coolant temps on older cars. The systems are more efficient at cooling running at the higher temps, the engines are happier and are cleaner (for emissions and internally), get better fuel economy and last longer running at the higher temperatures. The cooling fans are only activated at 225 degrees or above so anything below that is considered ice cold by the engineers that designed the system. There is no need to slow down, pull over and idle or do anything out of the ordinary regarding the cooling sytem. Drive it and quit worrying.

Just service the cooling system every 5 years or 100K by draining and refilling with fresh 50/50 DexCool/distilled water to keep the corrosion inhibitors in the coolant fresh to prevent any internal corrosion. That's what causes blown head gaskets. Lack of cooling system maintenance over the long haul.

If you search using "coolant temp" or "DexCool" or "coolant" or things like that there is a ton of info in the archives of this site that should set your mind at ease.

julio
04-12-04, 09:34 PM
I have bad gaskets, the tell tell sign is in cold weather when you leave the white cloud, in warm weather all you can do is wait for the low collant level. The northstar is aluminum if you're not loosing water then no worry, Check the belt on the waterpump, not knowing you engine or the last time you've changed the belt might be time for a new one. The other thing to look at is having the termostat changed, I 4 is orlando or Tampa, I'm in Jax I notice ,y temp guage running slightly over 220 in 85 +weather. make sure your fans are running. The other things that screw you up is if the computer is getting a good reading but the presentation is screwed up(the guage is broke) it's not worth tearing the dash apart and ask your service rep if he can test for a bad gage without raping you in the process.


Julio:bouncy:

97d'elegance
04-12-04, 09:46 PM
Thank you Anthony! You put my mind at ease. First thing in the morning my DIC is going OFF! Thanks again!

Anthony Cipriano
04-12-04, 09:51 PM
You'll be fine. The same sensors that send the coolant info to the DIC control the limp home mode and other coolant temp functions and that sensor is backed up by the onboard diagnostics for checks and remedial action if a failure is detected so there is little or no worry about the automatic system warning you if there is a problem. Unless red lights start coming on the system is fine. Even then it will protect the engine.

RLLOVETT
04-12-04, 11:53 PM
(Stop me if I'm repeating myself, but...) My 94 had a 'limp-home' episode a few weeks ago and is using coolant without leaking it. The distinctive odor of ethylene glycol seems a little more pronounced each day. The dealer won't touch it ("too many miles"/129k), no independent mechanics will touch it ("I theenk it's intake gasket")...but I'm just wondering if the more noticeable odor is something that would keep me from adding coolant and driving it till it quits? Also, for a while, the 'low coolant' message would appear but not anymore--blown sensor? tired of repeating the same old story?

Olds3.5
04-13-04, 09:26 AM
I think that you are observing the "heat soaking" effect of the cooling system. When you are running, say at 75 mph, the combustion heat is in equilibrium with the performance of the cooling system. If you suddenly get caught in traffic or something similiar that causes you to slow down, the heat in the engine suddenly has to be dissipated by a cooling system with less air flow and slower circulating coolant (lower rpm). The temp may rise sudddenly temporarily at that point and this effect is called heat soaking.

Anthony Cipriano
04-13-04, 11:17 AM
(Stop me if I'm repeating myself, but...) My 94 had a 'limp-home' episode a few weeks ago and is using coolant without leaking it. The distinctive odor of ethylene glycol seems a little more pronounced each day. The dealer won't touch it ("too many miles"/129k), no independent mechanics will touch it ("I theenk it's intake gasket")...but I'm just wondering if the more noticeable odor is something that would keep me from adding coolant and driving it till it quits? Also, for a while, the 'low coolant' message would appear but not anymore--blown sensor? tired of repeating the same old story?

Dose it heavily with the GM coolant supplement pellets/BarsLeaks "golden seal" powder (installed in the radiator hose not the surge tank) and drive it. Keep it full of coolant and it will be fine. I have heard of one Northstar in particular with symptoms like you describe going 100,000 miles after the symptoms started - uses coolant regularily but runs fine. Keeping the system full of the BarsLeaks will help prevent any coolant intrusion into the cylinders when the engine is shut down as the most obvious potential problem is filling a cylinder with coolant and hydrostatically locking it on startup. Rare but could happen if the leak gets bad enough.

caddyjax
05-05-04, 10:18 PM
i know im coming into this conversation pretty late, but i just got a 94 eldorado and i have had nothing but cooling issues from (*literally*) day #1. :banghead: this is putting it lightly!!!!!!!!!

from what i am reading i should turn of my DIC too...

my temp runs normaol around 199 to 203. i freak out at 226 to 230 and i shut it down at 255.

are you guy telling me that this is normal????:bonkers:

new to problematic caddys. but very willing to stay and endure it for the comfort and driving pleasure od the cadillac style.

anything helps...especially from service reps. HINT..HINT...:shhh:

Anthony Cipriano
05-06-04, 11:59 AM
i know im coming into this conversation pretty late, but i just got a 94 eldorado and i have had nothing but cooling issues from (*literally*) day #1. :banghead: this is putting it lightly!!!!!!!!!

from what i am reading i should turn of my DIC too...

my temp runs normaol around 199 to 203. i freak out at 226 to 230 and i shut it down at 255.

are you guy telling me that this is normal????:bonkers:

new to problematic caddys. but very willing to stay and endure it for the comfort and driving pleasure od the cadillac style.

anything helps...especially from service reps. HINT..HINT...:shhh:


No. 255 isn't normal. The system can go to 255 and not boil due to the 50/50 coolant/water concentration and the 15psi pressure cap on the system, but 255 regularily is not normal. Seeing 225-230 is really no need to freak out as those temperatures are common and normal. But 255 is getting to the range that if you are commonly seeing it something is wrong.

Don't know what work or diagnosis has been done to the system but something needs to be done before it erupts completely. Have you replaced the coolant every 2-3 years/24-32k miles? The conventional green coolant in your system needs regular replacement to keep the system fresh and protected from corrosion. The corrosion inhibitors in the system become depleted beyond that service interval and internal engine damage can result, ie head gaskets.

Check the coolant strength carefully with a refractor style tester. If the system is not charged with 50/50 coolant/distilled water that could be causing an overtemp problem due to premature boiling of the system.

Check the water pump drive belt and tensioner. On a 94 the water pump belt is likely worn and the tensioner may be frozen in position such that the water pump is not being driven correctly ie it's slipping. The water pump drive belt is on the rear of the engine on the left side of the engine (front side). It is driven by a small belt that is separate from the main serpentine system on the front of the engine. Make sure the belt is good and that the tensioner is moving freely. Exercise the tensioner and lube the pivot point to make sure it is working correctly.

If it is the original thermostat you might consider a replacement. After 10years/100,000 miles the thermostat doesn't owe you anything and should be considered a normal maintenance item. They do "wear out" and lose their effectiveness.

If the cooling system has not been maintained regularly with fresh coolant there may be clogging of the system due to deposits and gelled coolant (old coolant tends to gel due to silicates parcipitating out of solution). Draining and refreshing with fresh coolant may help.

caddyjax
05-06-04, 10:11 PM
thanks for the advice. i was concerned very much with 255 degrees , so i shut it down and bite the bullet of a tow truck. glad i did.

since then i found a leaking radiator end cap and had it replaced. also the thermostat was replaced and a new 15 lb cap. since then it still runs around 196 to 207 (ish). is this normal running temp?

car has 80k on it and is pretty decent other than little things popping up and noyt working temporarily. ??got me? the alternator , im told is going out, so i an contributing many things to that.

i have a knock up front that sounds like a bad strut. the dealer tells me $858 for a ONE (1). WHOOOHHH. now the local advance auto parts tells me they can get one for a 93 eldorado for (get this) $75. but the listing for a 94 is not available (says "see paper catalog"). whats the difference of 93 to 94? this car is not a ETC. can i get away with the 93 strut???

im not trying to be cheap, but $7?? difference is nothing to sneeze at...right?

anyway, im glad i found you guys. hope i learn enuff in a short period of time to help someone else.
thank you all.

RLLOVETT
05-07-04, 12:04 AM
Try these guys for the passive (cheap) strut replacement: http://www.arnottindustries.com/products/index.asp

Don97
05-08-04, 06:29 PM
I just bought a 97 D'elegance and I was concerned about temp also but you made me feel better. Would you know if I have any opinions on my other problem. I need a remote (#2 remote) for factory system?

Lawrence
05-10-04, 03:25 AM
I just bought a 97 D'elegance and I was concerned about temp also but you made me feel better. Would you know if I have any opinions on my other problem. I need a remote (#2 remote) for factory system?
"options"?

You can go to the dealer, or try ebay. There usually a lot of them there.

Lawrence
05-10-04, 03:26 AM
thanks for the advice. i was concerned very much with 255 degrees , so i shut it down and bite the bullet of a tow truck. glad i did.

since then i found a leaking radiator end cap and had it replaced. also the thermostat was replaced and a new 15 lb cap. since then it still runs around 196 to 207 (ish). is this normal running temp?

car has 80k on it and is pretty decent other than little things popping up and noyt working temporarily. ??got me? the alternator , im told is going out, so i an contributing many things to that.

i have a knock up front that sounds like a bad strut. the dealer tells me $858 for a ONE (1). WHOOOHHH. now the local advance auto parts tells me they can get one for a 93 eldorado for (get this) $75. but the listing for a 94 is not available (says "see paper catalog"). whats the difference of 93 to 94? this car is not a ETC. can i get away with the 93 strut???

im not trying to be cheap, but $7?? difference is nothing to sneeze at...right?

anyway, im glad i found you guys. hope i learn enuff in a short period of time to help someone else.
thank you all.
If you go aftermarket you'll need to replace them in pairs, front or back.

86caddtwithflows
05-10-04, 05:56 PM
next time it hits 240 or so u need to grab the top radiator hose and then the bottom if the bottom is cooler than the top your thermostat is prolly getting stuck...dont wait till one of those hoses blows though

Don97
05-12-04, 10:06 PM
Thank you I'm looking into the remote thur e-bay and looks like I have a strong chance of saving about $120.00 Thanks again

Don :)


"options"?

You can go to the dealer, or try ebay. There usually a lot of them there.

94eldorado
04-09-06, 09:48 PM
........... The cooling fans are only activated at 225 degrees or above so anything below that is considered ice cold by the engineers that designed the system...........


I know this is really coming in late in the discussion but what the heck I need some advice and don't know where to get it but here.

Hello I'm new here and I have a question concerning electric cooling fans. Every car with electric fans I've owned had the fans come on when the A/C came on. Is this true with my car as well or is it as you said and do not come on until 225 degrees? Is there a test I can perform to see if my fans are even working?

Ranger
04-09-06, 10:13 PM
I know this is really coming in late in the discussion but what the heck I need some advice and don't know where to get it but here.

Hello I'm new here and I have a question concerning electric cooling fans. Every car with electric fans I've owned had the fans come on when the A/C came on. Is this true with my car as well or is it as you said and do not come on until 225 degrees? Is there a test I can perform to see if my fans are even working?
Both. They come anytime the A/C is on OR when the temp reaches 224 without the A/C on. Test by turning the A/C on.

94eldorado
04-09-06, 10:26 PM
Both. They come anytime the A/C is on OR when the temp reaches 224 without the A/C on. Test by turning the A/C on.

I suspect Mine aren't working unless they are very quiet. If they do not work what next?

thank you for your response.

Ranger
04-09-06, 10:34 PM
Check the 3 relays between the fans.

zonie77
04-10-06, 10:11 AM
You start diagnosing why they are not coming on.

Can you troubleshoot electrical problems? Do you have a VOM? Do you have a service manual?

94eldorado
04-10-06, 09:38 PM
Check the 3 relays between the fans.

Forgive me for my lack of knowledge but how do I check the relays? How do I engage the A/C in an automatic system. I put the temp at it's lowest at 60 degrees but the outside temp is 55 degrees so it does not come on for me to see if fans are coming on.

By the way what are those pellets for after you flush the coolant system? What are they made of? Do you just disconnect the upper rad hose and toss them in?

Ranger
04-10-06, 10:46 PM
To tell you the truth, I am not sure how to check the relays. Hopefully someone will chimne in on it. Even at 45 degrees, the A/C should come on when commanded for dehumidification. In defrost mode, it will come on at any temp.

The "pellets" or "sealant tabs" aka cooling system suppliment are ground ginger root. Get them at any GM dealer or look for Barsleaks product "HDC" (tabs) or "G12BP" (powdered). They go in the radiator hose (high flow area), not the surge tank (low flow).

mtflight
04-12-06, 09:11 AM
Forgive me for my lack of knowledge but how do I check the relays? How do I engage the A/C in an automatic system. I put the temp at it's lowest at 60 degrees but the outside temp is 55 degrees so it does not come on for me to see if fans are coming on.

I noticed this too. When it's warm outside, and car is at operating temperature and you command the AC on, the fan will come on.

If it's cold and car not at operating temp--it won't turn on.

In the mess or replacing my AC clutch diode, I blew a fuse in the circuit. That same fuse controlled my AC clutch as well as the fan relays. So I got a check engine light. I looked up the codes and sure enough there was a code telling me the fan relays were inoperable.

I did not know that it was the same circuit... so I thought something was wrong with my fan relays and spent a few hours trying to figure that one out (I did not want to drive without fans!).

I figured it out in the AM, when I changed the fuse and they started working again. This I verified in the service manual too--fuse is in the same.

If your A/C works (by this I mean it produces cold air), then the fuse is okay. What are you temperatures looking like? If they are normal, try running without AC and see if the temperature climbs at idle in traffic. It should go up to 220, then the secondary fan kicks in.

Did u pull any codes? Sometimes you get lucky and the car will tell you what is wrong. Other times no clue (AC clutch diode--no codes).





By the way what are those pellets for after you flush the coolant system? What are they made of? Do you just disconnect the upper rad hose and toss them in?

mjd
04-12-06, 10:49 AM
hello
I had this same problem when I test drove a mustang for my kid, I tramped on the throttle and the temp increased, when I let it off It returned to normal. We brought the car in the shop putting it up on the hoist and all it was, was a loose clamp that was replaced. We only added coolant to the viehicle, it was fine after that, as we purchased the viehcle and had no problems since.

walterroc
04-12-06, 11:20 AM
I have a 98 Eldorado. How do I access the coolant temp through the DIC. Is it an intial set up issue.

mtflight
04-12-06, 12:00 PM
By the way what are those pellets for after you flush the coolant system? What are they made of? Do you just disconnect the upper rad hose and toss them in?

True story. Back in 1958 during a mission, the first nuclear submarine ,USS Nautilus, suffered a small leak in its condenser system. This jeopardized the mission and could have damaged costly equipment so they sent the crew dressed in civilian clothes to purchase as much Stop-Leak as possible and dumped it in the system.

The problem was solved, and did not reocurr.
http://www.historylink.org/essays/output.cfm?file_id=3739


Due to casting porosities in aluminum, this same stop-leak supplement is a factory additive. Note that as Ranger mentioned, it is made out of ground ginger root and walnut shells. Don't get the ones that look like Rabbit pellets in oil or any of that other aluminim or whatever stuff. It won't work the same and could clog a passage.


You don't need to, or should, flush the cooling system as it introduces harsh chemicals and to get them out you need to use lots of tap water, thereby introducing minerals.

Simply drain and refill. Prior to refilling, you put the tabs in (4 I believe) or the tubes (2) that Ranger mentioned (both are made by the same company that saved the USS Nautilus from embarrassment and failure).

We like to use distilled water and coolant in a 50/50 concentration.

If your car came with green, stick to green. If it came with Orange, stick to Dex-Cool.

Once you put green in an system that was orange, you may as well keep using green because you get no added benefit from using orange thereafter (IIRC something regarding sylicates plating the internals?).

mtflight
04-12-06, 12:03 PM
I have a 98 Eldorado. How do I access the coolant temp through the DIC. Is it an intial set up issue.

look through my posts, I know I've posted how to do it in the past (as have others).

It's risky so be careful to follow the directions at your own risk.

mtflight
04-12-06, 04:43 PM
I don't have the Factory Service Manual handy, but I found a link to a post that explains how to add the digital readout:

http://cadillacforums.com/forums/northstar-performance-technical-discussion/25463-how-do-i-get-temp-reading.html

Be careful to not mess up the math, or you could have a ruined instrument panel cluster in your hands.

94eldorado
04-13-06, 12:41 AM
To tell you the truth, I am not sure how to check the relays. Hopefully someone will chimne in on it. Even at 45 degrees, the A/C should come on when commanded for dehumidification. In defrost mode, it will come on at any temp.

The "pellets" or "sealant tabs" aka cooling system suppliment are ground ginger root. Get them at any GM dealer or look for Barsleaks product "HDC" (tabs) or "G12BP" (powdered). They go in the radiator hose (high flow area), not the surge tank (low flow).

You were right I put on defrost mode and the fans started. They seemed slow though. You can feel the flow but I'm use to allot more flow. Do the fans vary in speed depending on need? They seem so quiet is this normal?

mtflight
04-13-06, 12:45 AM
You were right I put on defrost mode and the fans started. They seemed slow though. You can feel the flow but I'm use to allot more flow. Do the fans vary in speed depending on need? They seem so quiet is this normal?

Yes IIRC they do vary in speed. They're electic and they're designed to be quiet.

94eldorado
04-13-06, 12:56 AM
Another question please.

What's the proper step-by-step procedure in coolant flush? What's a good radiator flush and anti-freeze and how many do I need to get 50/50 coolant. Besides the pellets do I put any other additives? How about water wetter type products? After flush do I need to bleed the system as is needed in some newer cars?
Anything I have to look out for or take certain precautions?

Thanks in advance

94eldorado
04-13-06, 01:02 AM
Yes IIRC they do vary in speed. They're electic and they're designed to be quiet.

Thank you
Yes I know they are electric but I've heard electric fans before and have been allot louder than the Cad's. If so these are the quietest fans I've ever heard or lack of. I had to actually see if they were running at all.

mtflight
04-13-06, 01:30 AM
Another question please.

What's the proper step-by-step procedure in coolant flush? What's a good radiator flush and anti-freeze and how many do I need to get 50/50 coolant. Besides the pellets do I put any other additives? How about water wetter type products? After flush do I need to bleed the system as is needed in some newer cars?
Anything I have to look out for or take certain precautions?

Thanks in advance

There is a tiny drain on the bottom of the radiator, almost like a key. It is located at the bottom facing the engine, on the driver side.

It may be more difficult than to just undo the lower radiator hose and let it all come out.

No block drain on the N*.

I believe the system holds 12-14 qts (check your owners manual).


Flush is neither required nor recommended. Just drain, put in the Barsleak product in the hose (NEVER in the tank), and refill through the normal path.


Ir you have a 94 get a brand antifreeze, and gallons of distilled water (cheap at store). Pre mix it in the gallon containers and pour it in.

I think to burp it you run it to 2500 RPM with the reservoir open a few times. Then when it reaches op temp you turn it off. It is a self purging system. Keep the premix in the gallon container, and check level cold for a few days.


You won't get any benefit out of running water wetter. I thought I did for a while.. maybe 1 or 2 degrees... not really significant. The only way to get lower temp results with water wetter is to use plain water which will kill the headgaskets fast.

blunted
04-13-06, 12:11 PM
Call it a coincidence but after I used some water wetter my 94 Eldo starting running a little cooler.. didn't see 230 after that.

mtflight
04-13-06, 01:09 PM
Call it a coincidence but after I used some water wetter my 94 Eldo starting running a little cooler.. didn't see 230 after that.

If you started using the AC more frequently the temperatures would remain closer to 200 degrees.

On the Water Wetter packaging it states it would not be as dramatic of an improvement on an ethylene glycol based system.

I may have noticed the slight decrease (or wanted to) in temperatures. But mine were never going as high as 230. A few months later my radiator cracked, and although it is likely very unrelated I have not gotten the courage to pour it in again.

chevelle
04-13-06, 05:33 PM
In moderate weather the fans actually do not run very often. Just at longer idles and when the AC is on in warmer weather. The fans have different speeds so you are not going to just hear them unless they are on high...and high is usually reserved for the hottest conditions.

Let the car sit and idle for 10 minutes or so when it is hot and open the hood and watch the fans and see.

STS 310
04-13-06, 07:05 PM
The "pellets" or "sealant tabs" aka cooling system suppliment are ground ginger root. Get them at any GM dealer or look for Barsleaks product "HDC" (tabs) or "G12BP" (powdered). They go in the radiator hose (high flow area), not the surge tank (low flow).

Lower radiator hose, you dont want those things getting in the t-stat right off the bat!

Also dont crush them, put them in whole as they will disolve.

Ranger
04-13-06, 08:16 PM
Lower radiator hose, you dont want those things getting in the t-stat right off the bat!

Also dont crush them, put them in whole as they will disolve.
When I did my '97 and again when I did my daughters '99 I stuck them in the upper and never had a problem. Gonna do mine in a month or so. Will have to see which is easier to get at.

P.S.
Love your avatar :thumbsup:

STS 310
04-13-06, 09:14 PM
Ranger

Do you remember my post about adding the crushed tabs to the upper hose?

What a nightmare, fouled the T stat, clogged the rad and overheated the day after I had a Welsh plug replaced.

I still dont have the supplement, kind of scared now....

Yea, the avatar.

Shes something else!

STS 310
04-13-06, 09:16 PM
Upper hose is easier with out a doubt, thats why my lazy ass used it.

Not anymore!

Ranger
04-13-06, 09:22 PM
I vaguely remember it and am surprised it would clog anything. I would think the water pump would push anything through there. Maybe I'll have to stuff mine in the bottom hose.

STS 310
04-13-06, 09:39 PM
Yea, the water pump circulates like a work horse, but it didnt that day!!!!!

96-deville-man
04-13-06, 10:48 PM
i saw temps of about 230 pretty often before i replaced my bad water pump, and beat up/leaking raditor. now it runs at 197 most of the time saw 220 once. 50/50 mix with water wetter.

STS 310
04-13-06, 11:03 PM
And THAT is NORMAL RANGE 96 Deville man.

220 and I get worried like a mother with her daughter at prom night.

I know I shouldnt but Im in a support group for it.

94eldorado
04-14-06, 11:53 PM
There is a tiny drain on the bottom of the radiator, almost like a key. It is located at the bottom facing the engine, on the driver side.

It may be more difficult than to just undo the lower radiator hose and let it all come out.

No block drain on the N*.

I believe the system holds 12-14 qts (check your owners manual).


Flush is neither required nor recommended. Just drain, put in the Barsleak product in the hose (NEVER in the tank), and refill through the normal path.


Ir you have a 94 get a brand antifreeze, and gallons of distilled water (cheap at store). Pre mix it in the gallon containers and pour it in.

I think to burp it you run it to 2500 RPM with the reservoir open a few times. Then when it reaches op temp you turn it off. It is a self purging system. Keep the premix in the gallon container, and check level cold for a few days.


You won't get any benefit out of running water wetter. I thought I did for a while.. maybe 1 or 2 degrees... not really significant. The only way to get lower temp results with water wetter is to use plain water which will kill the headgaskets fast.

Thank you mtflight.

Why is flushing not needed or recommended and why are the pellets needed. Also why will the headgaskets fail if maintainance is not done on a yearly basis? I've never heard of such a finicky and picky motor

mtflight
04-15-06, 12:09 AM
Thank you mtflight.

Why is flushing not needed or recommended and why are the pellets needed. Also why will the headgaskets fail if maintainance is not done on a yearly basis? I've never heard of such a finicky and picky motor

Harsh flush chemicals introduced into cooling system, cannot be rinsed out without a lot of water. The water that you use would likely be from a hose (to rinse of the flush chemicals), hard to get all that out so in the end you end up contaminating it with minerals which will buildup on the inside.

The green coolant has anti-corrosive additives that wear out. I believe 2 years, not every year. The headgasket has metal that rusts, if the anticorrosive additives deplete.

Rust a headgasket, and you spring a leak!

Any engine is prone to corrosion if the coolant is left in there beyond its useful span. Difference is in order to replace a headgasket on the Caddy, you need to drop the cradle and timesert the headbolts. So... its good preventive maintenance to avoid that costly expense.

94eldorado
04-16-06, 09:45 PM
Harsh flush chemicals introduced into cooling system, cannot be rinsed out without a lot of water. The water that you use would likely be from a hose (to rinse of the flush chemicals), hard to get all that out so in the end you end up contaminating it with minerals which will buildup on the inside.

The green coolant has anti-corrosive additives that wear out. I believe 2 years, not every year. The headgasket has metal that rusts, if the anticorrosive additives deplete.

Rust a headgasket, and you spring a leak!

Any engine is prone to corrosion if the coolant is left in there beyond its useful span. Difference is in order to replace a headgasket on the Caddy, you need to drop the cradle and timesert the headbolts. So... its good preventive maintenance to avoid that costly expense.

Well I did it but have some concerns. Emptied fluid through lower hose filled with distilled water then emptied again until I got clear water. Allot of distilled water. Mixed 50/50 plus 5 pellets (missed one) in separate containers. Only used one and ¾ gallons though. I'm afraid I have less than 50/50 mixture. What should I do? Should I put soom rust inhibiters?

mtflight
04-16-06, 09:57 PM
Well I did it but have some concerns. Emptied fluid through lower hose filled with distilled water then emptied again until I got clear water. Allot of distilled water. Mixed 50/50 plus 5 pellets (missed one) in separate containers. Only used one and gallons though. I'm afraid I have less than 50/50 mixture. What should I do? Should I put soom rust inhibiters?

To avoid having the ratio off, it's best to pre-mix (no rinse is necessary). Next time all you should have to do is drain and refill.

I think you are better off than with old coolant anyway. Hopefully someone with more experience will chime in.

96-deville-man
04-16-06, 10:22 PM
And THAT is NORMAL RANGE 96 Deville man.

220 and I get worried like a mother with her daughter at prom night.

I know I shouldnt but Im in a support group for it.

yep runs perfect no worries. i just didnt like seeing 230. lol its fixed now.

deantreat
11-24-11, 03:46 AM
What a FANTASTIC source of valuable information. My 95 Deville Concours chewed up the coolant pump belt, overheated in no time, and was missing so badly I was sure I'd ruined the engine...but behold limp home mode! Worked exactly as designed. Once I finally discovered the shredded belt (way over on the opposite side as the serp belt), I went ahead and bought a pump, tensioner pulley and camshaft end pulley (both ruined by melted rubber hardened in the belt groove). The tensioner pulley itself still spun freely, so that left the pump as culprit. As per a Haynes manual, I borrowed the special pump removal socket, and for two straight evenings failed to catch that thing right enough to free up the pump from it's housing. Read both schools of thought regarding application of impact wrenches, borrowed one, and removed that sucker with one blip of the trigger. Everything went back together just fine. Flushed the coolant, included the sealant tabs in the refill.
It started and ran fine, and with each check it appears my head gaskets are fine. But why no temp gauge on my Concours? It didn't take long to come across the procedure for fooling my Concours into acting like and Eldo, thus giving me a temp reading any time I want it. And I have that sucker displayed at all times.
Must say though, my system appears to be running about right, with highway criuising in the 65 to 75 mph range, up and down grades at temps up to 90F, my readout varies from 190 to 207, with 196 being the most common reading. In town it's higher on average, about 200 being the happy medium and peaking at 219. I imagine this summer I'll see corresponding higher highs, but I'm much more confident that all is good with my ride, thanks to all the knowledge shared on these forums.

Submariner409
11-24-11, 10:38 AM
deantreat, Good find of an old thread.

There's more on cooling systems and operation - a lot more - in here, Seville, and in Discussions, Item Specific: Cadillac Tech Tips and Northstar Performance.

Your thermostat is set to begin at 188 and fully open at 206. Your running temps are perfect. Once in a long while, with no A/C function set in heavy traffic (no fans in SLOW) you'll see the temp go to ~224, fans will come on, the temp will go down to 213, fans go off, cycle repeats.

Fans go to FAST at 236 or at a transmission fluid temp of 304 - yep, 304.

Click on my username, open my profile; two albums, 6 pages of diagrams and pictures, many applicable to your engine - especially the plug/coil wiring diagrams and water pump drive system.