Author Topic: 73 eldo. engine temp question again  (Read 452 times)

Offline cadillacmike68

  • Posts: 1140
  • Still finishing up this 1968
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  • Name: M Santos
Re: 73 eldo. engine temp question again
« Reply #20 on: November 07, 2017, 08:41:41 AM »
OK, Time to weigh it.

First, KK, get your buzzer fixed. When that goes off you are at critical engine metal temp levels.

When I read about Tassie forgetting to put his radiator cap back I thought , that was a DUH moment, but its a sure fire way to blow out almost all your coolant and that will set off the buzzer metal temp light.

I was always bitchn' about my temp gauge - yes 1968s have a temp gauge (1968 is the first year of the 472 and the only year for a temp gauge in the 472-500-425 engine family) always creeping up when stopped when it is hot which is 11 months out of the year here in Florida. But the buzzer and "Engine Temp" never went off. And that bad boy crept up past 3/4 a few times.

1968 was sort of a a transition year. It was the last year for a no overflow-recovery radiator, so these cars had a temp gauge. But we fitted a 1969-70 recovery tank inside the fender well (because it was too tall to fit where the 69-70s have it)  and I changed to the AC RC-27 cap. What they didn't have was the green turn signal arrows! In 1969 they took out the temp gauge when have the coolant system self recovering.

In any event no matter what I tried that gauge would creep when stopped and would go back down when I got moving again, and I was concerned. There are a couple threads on this from last year that I started. 

However the engine temp light / buzzer never went off and the coolant never blew out of the recovery tank. sure some went in there occasionally, but it never blew it out the plastic tank. I used a fluke infrared temp gun and could see the temp progression from the driver side of the radiator to the passenger side from about 220 down to 140 and then t would jump back too over 180 whrn it hit the passenger side tank because that there the transmission lines went in and that was hot. But I could see that the system was more or less working. I just wasn't comfortable with the gauge spiking when iit was stuck in traffic. Now the traffic today was NEVER this bad in 1968 so again I was concerned.

Fast forward to this past May when Igot a sudden LOUD rod knock and Iended up having the caw towed home. When I finally got to a shop and they tore it down we found the problem that I discussed here:

http://forums.cadillaclasalleclub.org/index.php?topic=145138.0

In any event there was Absolutely NO evidence of any harm done to anything from overheating. I still had my radiator re-cored to a supposedly more efficient core and an changing the fan to a 1970 style 7 blade no clutch one I bought a Derale vented transmission pan (  http://derale.com/products/transmission-pans/cooling-pans/6an-male-x-3-8-barb-detail ) and I'm considering putting in a secondary transmission and engine.oil cooler (Derale stacked plate versions).  But we'll see how it runs this fall and winter. I'm also considering oil pressure and volt gauges but that's a different story.

On the three or 4 port switch below the distributor. You should verify that yours works, because in provides additional vacuum advance when the engine coolant gets up above 220F that advances timing which helps the engine run a bit cooler. new ones are out there (mostly on fleabay) if you need one.

If you want to put in a coolant temp gauge, you might be able to splice off the existing coolant temp sender, but if the coolant temp (and I'm not sure what that light 's wording is) doesn't light up and you are not blowing coolant out the cap or out the overflow tank, I would leave it alone.  Just make sure your fan and clutch are working and it should be fine. If the coolant is blowing out, you should see AND smell it. You do need to know which light is which and your owners manual will tell you. I don't have a 73 manual, but I think there's one down where my car is because there are two 1973 ElDorado convertibles there.



Regards,
"Cadillac" Mike
Current:
1968 DeVille Convertible
1996 Fleetwood Brougham
2009 STS NorthStar Platinum ed RWD
2011 CTS PRemiun ed Sedan RWD
Past:
2008 CTS Premium ed Sedan AWD
2005 CTS Hi-Feature Sedan RWD
2000 ElDorado ESC Hard Boot Convertible
1995 Fleetwood Brougham
1973 Sedan DeVille
1970 Fleetwood Brougham
1969 DeVille Convertible

Offline kkkaiser

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Re: 73 eldo. engine temp question again
« Reply #21 on: November 07, 2017, 11:21:12 AM »
I have never seen the coolant come out,  in fact, i was checking fluids on all cars the other day before we got hit with a big freeze up here in MT and it was full.   

it just seems when i go for a ride, and come back and for what ever reason i choose to lift hood, it seems hot under there. 

i have had the engine light flicker one time, on a hot day in yellowstone stuck in a bear jam. at 7500 feet,  and luckily, the ranger allowed us to mover forward and as soon as we got moving, it went off and never saw again,   during the eclipse on aug.  i got stuck in miles of bumper to bumper traffic, it was hot, and it never got the warning,,

i just dont like that heat metering system.. i think i did find the buzzer under the dash, but its rusted.  i would be happy with the type that is in my63,, just a 1/4 rating,  at least you can see buildup,  before hand, and pull over, or do what ever to get the heat down,, like in stuck traffic,

anyway, still kicking it around,, car isn't a show car and i dont like adding those gauges but if it protects the car,, i think its a reasonable thought to have,

anyway, thanks for al the input..

Sincerely

Kim

Offline Jeff Rose CLC #28373

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  • Name: Jeff Rose
Re: 73 eldo. engine temp question again
« Reply #22 on: November 07, 2017, 02:03:50 PM »
Just remember that even tho traffic is worse than it was back in the day, and even if your cooling system isn't as efficient as it was back in the day,  that the light still comes on at the same temperature it was designed to. Too hot is still too hot-gauge or no gauge. And not too hot is still not too hot-gauge or no gauge.
Jeff
Jeff
CLC #28373
1970 Coupe DeVille
1955 Series 62

Offline Eric DeVirgilis CLC# 8621

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Re: 73 eldo. engine temp question again
« Reply #23 on: November 07, 2017, 02:25:06 PM »
Cadillac thoughtfully provided two temperature monitoring lamps- Coolant Temp and Stop Engine providing a modicum of warning, long before things get out of hand.

If the car lasted 45 years without a temperature gauge, is there really any compelling reason to add one now?  ???
A Cadillac Motorcar is a Possession for Which There is no Acceptable Substitute

Offline V63

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  • Name: W Link
Re: 73 eldo. engine temp question again
« Reply #24 on: November 07, 2017, 03:12:17 PM »
One way to avoid a surprise overheat is to eliminate the clutch fan (if equipped) for an OEM flex fan.

When the clutch fans fail...the first subtle symptom is overheating.

They also make aftermarket flex fan versions...but you probably want to avoid more aggressive versions (they are out there) and opt for more OEM specifications. The aggressive ones are pretty noisy.

Offline cadillacmike68

  • Posts: 1140
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Re: 73 eldo. engine temp question again
« Reply #25 on: November 07, 2017, 10:33:07 PM »
...it just seems when i go for a ride, and come back and for what ever reason i choose to lift hood, it seems hot under there...

Of course its hot under the hood after a run. I have a hood light , merc switch, under the hood and when I go to shows in the daytime I like to take that bulb (an 1156) out to lessen battery drain. That bad boy always burns my fingers, even if I immediately try to remove it. Sometimes even opening the hood burns my fingers. Yeah they get hot.

Just remember that even tho traffic is worse than it was back in the day, and even if your cooling system isn't as efficient as it was back in the day,  that the light still comes on at the same temperature it was designed to. Too hot is still too hot-gauge or no gauge. And not too hot is still not too hot-gauge or no gauge.
Jeff

But my cooling system is more efficient that it was back in the day.

One way to avoid a surprise overheat is to eliminate the clutch fan (if equipped) for an OEM flex fan.

When the clutch fans fail...the first subtle symptom is overheating.

They also make aftermarket flex fan versions...but you probably want to avoid more aggressive versions (they are out there) and opt for more OEM specifications. The aggressive ones are pretty noisy.

Remember that Cadillac used a non-clutch fan in 1970 and for at least 1-2 years from 1976-78 or 79.  You want the 7 blade one. They are out there but are sometimes hard to find. You also need a fan spacer. The originals are also out there - they look much better. If you need one PM me. I wouldn't trust an aftermarket fan, especially a cheap chinese made one. I have heard how the blades fly off and rip everything to shreds in the engine bay.


« Last Edit: November 07, 2017, 10:39:34 PM by cadillacmike68 »
Regards,
"Cadillac" Mike
Current:
1968 DeVille Convertible
1996 Fleetwood Brougham
2009 STS NorthStar Platinum ed RWD
2011 CTS PRemiun ed Sedan RWD
Past:
2008 CTS Premium ed Sedan AWD
2005 CTS Hi-Feature Sedan RWD
2000 ElDorado ESC Hard Boot Convertible
1995 Fleetwood Brougham
1973 Sedan DeVille
1970 Fleetwood Brougham
1969 DeVille Convertible

Offline smokuspollutus

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  • Name: A. Molinaro
Re: 73 eldo. engine temp question again
« Reply #26 on: November 08, 2017, 12:14:30 PM »
OP, if all is working as designed, you need neither a gauge nor a light/buzzer. At 45 years old though, it is more likely than not that everything is NOT working as designed. Since the light is coming on after sitting in traffic, you have an issue that the gauge is not going to shed any more "light" (sorry for the pun) on. Assuming all adjustments were made correctly, you should answer these questions: What is the radiator (plastic/alum 1 row, copper 2/3/4 row, high efficiency core, etc.), how old is it (kind of like counting rings on a tree, check how many green drip marks are on the core), how old is the fan clutch and when was the last time someone did the water pump and left the fan sitting face down on the ground? A clutch fan with fluid still inside it will cool just as well as a flex but is quieter, has less power draw, and is easier on water pump bearings.

Older cars produce way more heat than the stuff of the last 20 years, don't let that alarm you.
1984 Eldorado Biarritz Coupe

Offline kkkaiser

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Re: 73 eldo. engine temp question again
« Reply #27 on: November 11, 2017, 12:55:09 AM »
thanks for all the thoughts,, lots to consider