Author Topic: 73 eldo. engine temp question again  (Read 438 times)

Offline kkkaiser

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73 eldo. engine temp question again
« on: October 29, 2017, 04:22:16 PM »
I am back at looking at putting a temp gauge on the 73 eldo,, i just dont like having a light come on,, just a basic gauge in quarter measurements would be fine, but I just dont like the light thing,

so i have honed some of my engine skills fooling with the 63,, I've redone brakes, reset choke, valve cover gaskets, had a odd occurrence with the gas syphoning in to the engine from being parked on too steep and incline,, put in petronix,, did the timing,,  just things, that have given me a bit more confidence to delve further.  I bought one of the temp gauges, and was going to put it under that valve with the three prongs, but the connectors supplied were not big enough to fill the hole. 

firstly, what exactly does the engine light that comes on at start up measure.. is it the engine metal heat from the temp sensor on the back driver rear or is it the water temp. 

if i undo the distributor, or alternator,, (dont remember which right now) to access that plug location and put the new temp gauge in would that effect the engine light that comes on then goes off at start up or.  if the engine was getting hot, would another light come on or would the engine light come on, and the newly installed temp gauge would be telling you if say you got to 220 or so on the water/coolant.

sincerely
Kim


Offline 35-709

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Re: 73 eldo. engine temp question again
« Reply #1 on: October 29, 2017, 06:40:00 PM »
DON'T PUT IN A WATER TEMP GAUGE!  All it will do is cause is worry and concern, you will fixate on it and wonder and worry about it all the time.  By the way, 220 degrees on a 472/500, etc. is not too high, you may well see 235 on a hot day with the AC on.  Those engines like to (and were designed to) run hot and that is normal, it may scare you.  Been there, done that.  The system as designed will let you know soon enough.
 
Your water temperature sending unit is below and in front of the air conditioning compressor.  You will have to loosen it on its mounts until you can raise the compressor's nose high enough to get in there --- you will have to loosen/remove the belts --- you will have to drain down the cooling system to a point where the coolant level is below the temp sensor or have coolant all over the place --- you may well have to search out and purchase an adapter to go in that large hole that will fit a gauge sensor in the other end.  Not worth it, it will not, IMO, give you peace of mind.  The temp. sensor behind the alternator (for the climate control system) and the engine metal sensor location at the rear by the left cylinder head are NOT suitable for a water temp. gauge --- they are dry holes.

For your own peace of mind, don't do it.  If you decide to do it anyway, don't buy cheap
« Last Edit: October 29, 2017, 08:08:30 PM by 35-709 »
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Offline The Tassie Devil(le)

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Re: 73 eldo. engine temp question again
« Reply #2 on: October 29, 2017, 07:09:14 PM »
I agree with Geoff.

These engines are designed to run hot, but not hot enough to damage anything.

It is necessary to run the correct Thermostat, and Pressure cap, as for every 1 Pound of pressure over atmospheric, the coolant temperature will rise 2 Degrees F.   Therefore, with a 15 Lb. cap, the temperature is rising to 30 Degrees F above the 212 Degree boiling point of water.   Yes, that is 242 Degrees F.

Bruce. >:D
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Offline Nye

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Re: 73 eldo. engine temp question again
« Reply #3 on: October 29, 2017, 07:24:14 PM »
Something else you could do is buy an infrared gun. I used it a few times when I first started driving the Cadillac and soon it got moved to the storage bin because all was well.

Michael
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Offline The Tassie Devil(le)

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Re: 73 eldo. engine temp question again
« Reply #4 on: October 29, 2017, 07:31:23 PM »
Yes, that is one of the better investments I have made, and use it everywhere, especially in my boat.

Very handy when trying to avoid spinning fans, and areas one cannot easily reach.

Bruce. >:D
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Offline 35-709

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Re: 73 eldo. engine temp question again
« Reply #5 on: October 29, 2017, 08:07:21 PM »
Antifreeze also raises the boiling point, another reason a 50/50 mix of AF and water is recommended.
1935 Cadillac Sedan resto-mod "Big Red"
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Offline Glen

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Re: 73 eldo. engine temp question again
« Reply #6 on: October 30, 2017, 01:28:33 AM »
Something else you could do is buy an infrared gun. I used it a few times when I first started driving the Cadillac and soon it got moved to the storage bin because all was well.

Michael
Those are very handy.  I have two of them.  But I really like my Flir TG130. 
http://www.flir.com/instruments/tg130/
It shows you a lot more and is really fascinating.  You see minor temperature variations.  And the spot in the center is measures the temperature.       It is a little on the expensive side though.  At $199 this is the cheap one.  They go as high as $7K. 
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Offline chrisntam

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Re: 73 eldo. engine temp question again
« Reply #7 on: October 30, 2017, 04:40:21 AM »
I'm surprised by the responses.  No temp gauge?

Don't you want to know?

Don't you want to monitor the engine's vitals?

I have the factory lights on mine, I also have a water temp gauge and a metal temp gauge.

I like to know.
1970 Deville Convertible  MTS 507
Dallas, Texas

Offline The Tassie Devil(le)

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Re: 73 eldo. engine temp question again
« Reply #8 on: October 30, 2017, 04:54:02 AM »
Funny thing is that when I purchased my '72 Eldo in 2007, I installed an oil pressure gauge as I didn't know the history of the engine, and as I was going to export it home with me at the end of my trip, I wanted to know what it was like, whilst driving it around USA.

Someone had installed a crappy aftermarket radio in the dash, wrecking it in the process, so it wouldn't hurt to cut a hole next to the radio, between it and the steering column.

When I got her home, I investigated the best place for a triple gauge set, under the dash, but anything within easy reading was too close to my legs, or too far away, so I didn't bother.

Plus, I wasn't going to put them on top of the dash, or up the side of the windscreen pillar, so I settled for the idiot lights.

Yes, I had gauges in my Hot Rods, and used them all the time, but my Cadillac is a cruiser, and doesn't need them.

Bruce. >:D
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Offline TJ Hopland

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Re: 73 eldo. engine temp question again
« Reply #9 on: October 30, 2017, 08:10:38 AM »
I'm mixed on the gauge no gauge thing.  IF you add them I would for sure leave the originals connected to the original lights just to give to that extra notification if something goes wrong quick or if someone else ends up driving your car for some reason.

His original questions.....

Three prong thing I assume he is speaking of the thermal vacuum switch.   That is a good location for a gauge.   The switches rarely work at this age and are more of an emissions thing than anything else so not really needed.    It is kinda under the distributor but you should not have to mess with the distributor to change it so not quite sure why you are talking about removing it.  And yes the common engines are one size smaller than these.   I think most are 3/8 and this is 1/2" and they are standard NPT pipe threads.   Any hardware / home store should have brass adapters.  You will run into the same issue with oil pressure if you do that.  I think standard is 1/8 and these are 1/4.

Stock 'water temp' light sensor is under the AC compressor and can stay.  Its actually in the same coolant passage as the thermal switch is so readings should be almost identical. 

There are two identical looking metal temp sensors in the corners of the heads.   The one behind the alternator turns on at 120*F and allows the heater blower to run on a speed higher than low in most modes.   Idea there is you don't want cold air blowing on you so it limits the speed till the engine is warm enough to make some heat.    In the same spot of the other head which ends up by the brake booster is the other one that trips at like 270*.  This one is attached to the 'engine temp' light and the buzzer so there are combinations of key in and door open that will make it light too.       
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Offline kkkaiser

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Re: 73 eldo. engine temp question again
« Reply #10 on: October 30, 2017, 08:32:02 PM »
ok, well,
if the engine light goes on after sitting awhile in traffic,, does that mean the block is getting to hot?

and what light will come on if the coolant is getting to hot.  its not that i want to have a cool look, but i just want to know where things are,, just to be able to see

or better yet,, at what temp do the lights come on so i can either pull over and shut down, or know to get some air moving through the grill.

Offline The Tassie Devil(le)

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Re: 73 eldo. engine temp question again
« Reply #11 on: October 30, 2017, 08:40:19 PM »
If the Stop Engine Light comes on, there will also be a loud buzzer sound, and you only have a short time to pull over and stop.   This means that you have lost all your coolant, and the engine will eventually seize.

The coolant light will com,e on a long time before that.

If the Block Temp light is on, don't attempt to try and start the engine so that you can slowly refill the radiator, as until the light goes out, the engine will not start.   How do I know?   Had that happen to me, and the engine got so hot it cooked the wiring loom, and destroyed some plug leads.   It seemed like Cadillac designed the system to cut the ignition power to the coil, as the Starter would still crank.

Bruce. >:D
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Offline kkkaiser

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Re: 73 eldo. engine temp question again
« Reply #12 on: October 30, 2017, 11:09:39 PM »
my buzzer is long dead but the light comes on at startup then goes off.  have never seen he water light come on, so I'm guessing the temp hasn't gotten up, but i had one instance where the engine light flickerd,, ,  but getting moving again out of stalled traffic, it went out and never came back on..,, it just makes me nervous not seeing a progression of temp.,,

Offline chrisntam

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Re: 73 eldo. engine temp question again
« Reply #13 on: October 31, 2017, 04:05:54 AM »
snip...

If the Block Temp light is on, don't attempt to try and start the engine so that you can slowly refill the radiator, as until the light goes out, the engine will not start.   How do I know?   Had that happen to me, and the engine got so hot it cooked the wiring loom, and destroyed some plug leads.   It seemed like Cadillac designed the system to cut the ignition power to the coil, as the Starter would still crank.

Bruce. >:D

Bet you wished you had gauges...

 ;)

Would have save the loom, leads and a lot of grief.

Just sayin'.
1970 Deville Convertible  MTS 507
Dallas, Texas

Offline The Tassie Devil(le)

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Re: 73 eldo. engine temp question again
« Reply #14 on: October 31, 2017, 05:13:16 AM »
Yes, but what actually caused the problem was I had checked the coolant level before heading off on a 100 mile drive, and for some reason, forgot to put the radiator cap back on.

I was just enjoying the drive and after driving around 25 miles, and climbing a small hill, the buzzer sounded, and I didn't have a clue what was going on, but I looked down at the dash panel, and glowing brightly was the Stop Engine Light.

At that time, having gauges wouldn't probably have made any difference to the outcome, as I was not "driving" the car, just cruising along, enjoying the countryside and conversing with my fellow passengers.

Having gauges doesn't mean that one is constantly looking at them.   But, occasionally glancing at them.

When I was driving my Dragster, I would look at them at start-up, at the Tree, then the next time was in the pits at warm-up before another run.

Bruce.   >:D
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Offline 76 cadillac bob

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Re: 73 eldo. engine temp question again
« Reply #15 on: October 31, 2017, 06:42:25 PM »
First thing I did was put in gauges on my 76 eldo conv. Had idiot lights on my 66 chevy and just about blew the engine years ago, failed to see it was on. The heat on these 500 engines is amazing, I just replaced the original radiator (80,000miles) and it runs much cooler, even with AC on going up hill or in traffic. I like to monitor my cars and gauges just to give me piece of mind. I guess I like to know if I am blowing up my engine..before it happens. I also reset timing that made a huge difference in the performance and cooling. The gauges are under the dash out of the way. Not the most ideal but it works. Besides water I have "oil" and "volts" not much I can say about them. My telltale lights still come on when I start the car, so I have a back up.

Offline The Tassie Devil(le)

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Re: 73 eldo. engine temp question again
« Reply #16 on: October 31, 2017, 06:51:52 PM »
G'day Bob,

In my experience, an idiot light will alert a driver well before a gauge, especially a gauge that is out of the way, where one has to completely move their vision away from the area of the factory dash and the road.

Yes, we say we will always look at the gauges, but in actual fact, we don't.

If the radiator starts to boil, especially in a '71 onwards, the steam escaping out the overflow bottle, will be seen coming out the left side of the hood/fender gap, and this alerts the driver to look at the idiot lights.   Happened to me when the alternator/fan belt delaminated and came off, and I didn't notice the generator light come on.

These cars run so hot, that there isn't much time between normal temperature, and pressure overload.

Bruce. >:D
'72 Eldorado Convertible (LHD)
'70 Ranchero Squire (RHD)
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(Past President Modified Chapter)

Offline dochawk

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Re: 73 eldo. engine temp question again
« Reply #17 on: November 06, 2017, 03:55:55 PM »
I lost an '83 Cougar to overheating, and have wanted gauges on everything ever since (yet I replaced it with an '89 Crown Victoria with no gauges--Hertz gave me such a good deal on a low mileage one that I could replace the engine and then some as compared to a new one).

The heat gauge was useful driving my '97 Eldorado Touring Coop back from southern California a few months ago--85 mph with an outside temperature of 117F was fine until the grade picked up a bit, at which point it would shoot up.  I drove home with my eye on the temp rather than the speedometer, as it had plenty of cooling until going just a tough too far (I think I'm 1/3 obstructed in the radiator, or need to replace the thermostat.  But I can't replicate the failure condition anywhere near here!).

i generally assume that I'll put a cluster in the ashtray of my '72.  Other times, I think I'll use bluetooth and an old iPad that can slide out from under the dash . . .

we just went through a round on my daughter's '89 Eldorado where after changing the thermostat, It was overheating at a reported temp of about 218, and full of water.  Seems that the radiator was too low to draw from the reservoir.  The coolant was indeed only 218F, but there wasn't enough of it . . .
1972 Eldorado convertible, 2001 Deville DHS (daughter), 1997 Eldorado ETC (and now my wife wants an Eldorado!)

Offline The Tassie Devil(le)

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Re: 73 eldo. engine temp question again
« Reply #18 on: November 06, 2017, 04:25:24 PM »
The funny thing about the idiot lights and fitting gauges in these cars is that one has to place them where they are immediately visible at all times.

I was taking notice of the idiot lights in my own '72 the other day, and when I am driving, and my hands are in the 10-2 position, which is the recommended position, my right hand is totally blocking out my vision of the idiot lights.   Not sure why Cadillac placed them there in the dash, but they didn't do it out of driver awareness.

As for where to put gauges?  As I said before, these dashes are not designed for stuff like that, but the ash receiver and cigar lighter are perfectly placed for the right-handed smoker.

If only I could find a slim-line, and I mean a really slim-line gauge set that I could mount up under the dash overhang, I would be tempted to place one there.   As I have converted my Speedo to Metric, I don't really want to ruin the looks.

Bruce. >:D


Bruce. >:D
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'70 Ranchero Squire (RHD)
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Offline Phil Weber

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Re: 73 eldo. engine temp question again
« Reply #19 on: November 06, 2017, 05:23:32 PM »
I used to run these gauges in the tractor and skid steer and have fitted one in the Cadillac . I run a double set ( TM4 ) which monitors the transmission as well . Has alarms for temp and oil pressure.
http://enginewatchdog.com/

Phil