Just got today my 1974 OLDSMOBILE CUTLASS SUPREME 5.7L. drove it uphill from tel aviv to Jerusalem. I really don’t know if the car was over heating, so I added a photo of my thermometer. I need to know if that is a normal temperature.
I stopped the car and saw that coolant was overloading from the cap of the plastic can next to the radiator. Another problem that happened is that the car did not start (the starter didn't work) again until I jumpstarted it. A friend told me that it is related to the heating.
I found out today that the car has an electric fan that works with manual switch addition to the mechanic fan. Will that keep the engine cooler?

 

Welcome to the site, nice car. Is the temperature with the engine running or off? Starting issues can be a weak battery, poor or corroded connections, etc... The electric fan apparently was installed due to previous issues.

 

What fan or fans were running when it overheated ? I'm assuming you have a 3 row rad in the car. Was the A/C on as well?

 

Thanks for your responses. The temperature stayed the same on the thermometer when i turned the engine off. Now i know i shouldn't turn off when the car is overheated. The a/c was off. The electric fen also was off. I didn't know it exists.
How can i know ir the rad is 3 or 4 row?
About the starting issues, the batary is new and the car was and still starting with no problem, except for the time the car overheated. Is there a mechanism that can prevent the car from starting when the car is overheating?

 

As the engine gets hotter, all of its parts expand, making everything tighter, so that it can become very hard to turn. Add to this the fact that electrical resistance increases with heat, and all of the slightly corroded connections in your starting system become more resistive, and you end up with an engine that won't turn over when overheated.

You need to post photos of your cooling system so that we can try to figure out what you need to fix.

- Eric

 

x2

I installed a thermal blanket on my starter to prevent heat soak. However, you definitely need to fix your overheating issue before doing anything else.

 

Another cause for heating that i think about is that i was stepping on the gas to check the car performances. At the rest of the way when i was cruising the temperature was normal.
Can it be the reason?
Dose the oversizing of the engine can cause overheating?

 

Depending on what has been done to the engine, what shape it is in, oil viscosity,Coolant level etc. yes getting on and off it in traffic could make it run hot.

 

I had to look this up. Tel Aviv is at sea level while Jerusalem is at about 2600 feet. The distance between the two is about 40 miles. Daytime temperatures at this time of year are in the 80s.

None of these, distance, elevation change, nor ambient temperature, should be at all taxing to a well-tuned, properly-running engine.

 

Let's review what we really know here as it's really not much. People are offering all kinds of advice about a problem that has not been identified.

First, the OP says that he doesn't know if the car is overheating. He drove it on a 40-mile, uphill trip without a problem. If the car had a serious overheating problem, he never would have made it that far.

Second, he shows a photo of the engine temperature gauge, but he doesn't tell us when that photo was taken. Engine running and idling in the driveway? Cruising at highway speed? Immediately after the engine was shut off?

The gauge, assuming it's accurate, shows 225 F. That's not an unreasonable temperature idling in traffic on a warm day and certainly not unreasonable after immediately shutting the engine off as the engine temp always rises immediately after shut-off as all the heat is still there but the cooling system is no longer functioning.

Third, he shows that coolant is overflowing the recovery bottle. That could be due to simply having too much coolant in the system.

Fourth, he asks if "oversizing" the engine could be the problem, if there is one. I think he means "over-revving" or simply revving the engine? He says he was "stepping on the gas to check the car's performance." This might cause the temperature to rise momentarily, but the engine certainly should be able to handle something like this without overheating. After all, you step on the gas all the time to merge in traffic when entering a freeway or to pass someone on a two-lane highway, and this doesn't cause the engine to overheat.



I think the bottom line here is that, with the information we have so far, there is no evidence that the car has a cooling system problem at all.


The hot-start problem is a separate issue.

 

Thanks for laying that all out clearly, Jaunty.

- Eric

 

X2... Jaunty makes some very good points. I had assumed it overheated spewing coolant into and out of the overflow bottle.

Eric H

 

I did a little geometry here, and this elevation change over this much distance is equivalent to an average incline of 0.7 degrees or 1.2% (1.2 feet of rise per 100 feet of travel). Negligible.

 

Wow. So much information. Thank you all.
I was cruising around in Jerusalem today for about half an hour, in a hot day and the engine didn't overheat. I added a photo of my temprature gauge. I didn't even turned on the electric fen.
To give you more details: the engine was overheating half way to jerusalem before the steep climbing. I am convinced that the heating was due to fast driving, about 95mph. With few kick downs. The first photo of the gauge was taken after i switched off the engin, with no significant change of temperature. I guess that spewing coolant into and out of the overflow bottle was because of too much coolant. I did not have to add more coolant after that.
The second half of the way to jerusalem is much steeper, and because i was just cruising on that way it didn't overheat again.
About the oversizing, the engin originally was 5.7, and it now something like 6.4.
In another forum someone said that 160 thermostat helped him to keep his engin cooler. I ordered one frome ebay. Does someone think I shouldn't install it?
And last question: can someone tell by the photos if my radiator is 3 or 4 row?

 

It almost looks like it could be a 4 row, ther isn't any over hang on the engine side of the core. Take the cap off with siffen some coolant out and see how many rows of tubes ther is across. It will be hard to tell looking at the core in the car behind the shroud. Thats why I suggest looking into the rad.

 

As is almost always the case in these situations, information that might be helpful isn't given initially, so we're all flailing around in the dark when trying to offer suggestions.

You didn't tell us before that you were driving at almost 100 mph. You just said you were going uphill. No, while the speedometers go that high, these cars are not racing cars and were never designed for sustained driving at that speed. We can't drive that fast on public highways in the U.S., anyway, unless we're morons.

I think it's entirely likely that your car could overheat when driving at a sustained 95 mph. But it doesn't overheat if you drive it at a more sane 60 or 70 mph, does it? As I said earlier, I don't think your car has an overheating problem, and I don't think your car has ever had an overheating problem. Just keep your speeds to something semi-reasonable, and your engine will be fine.

 

The engine has not been "oversized." What you mean is that the original engine has apparently been replaced.

5.7 liters is 350 cubic inches. 6.4 liters is about 400 cubic inches. That's probably why the electric fans were added. Whoever owned the car before replaced the engine, but the cooling system was not changed accordingly (although I can't believe it makes that much difference between these two engines). To keep the engine cool enough, the electric fans were added. Everything was fine until you decided to drive it at nearly the speed of sound, and then the cooling system's inability to cope with a car driven that fast became evident.


No. Your engine runs fine as long as you keep your speeds reasonable. The "someone" in the other forum is imagining things. The thermostat only controls the temperature at which the valve opens allowing coolant to begin flowing through the radiator. It does not control the temperature at which the engine operates. That's a function of the entire engine/cooling system design.


The more rows, the wider the radiator, generally speaking, but the "rows" themselves can be different widths, depending on the design, so the only way to know for sure is to remove the cap and look inside. You'll probably have to drain some coolant out, too, so you can actually see the rows. See the photo below for an idea of what to be looking for. Obviously, a 4-row radiator would have four rows of tubes.

Note that, in this example, the individual rows in the 2-row radiator are wider than they are in the 3-row, and these two radiators would be about the same width, externally. That's why you can't tell by just looking at the radiator externally. You have to look inside.

 

Thermostats work by setting a minimum operating temp, the cooling system takes over from there and the temperature will rise based on speed, outside air temperature, engine tune and cooling capacity of your system.

I think what might of happened with your brief run at the high temp is the thermostat may have stuck closed or possibly partially closed. I would change it, a 160 will probably work fine in your area, your winter temps get into the 40's F so you may have some issues in too low of an operating temp and limited heat. I would probably run a 180* thermostat.

 

This is a good point and something the OP should keep in mind. Running at too cool a temperature can be harmful to your engine just as much as running at too hot a temperature can be.

If you have a thermostat that opens at a low temperature and most of the driving of your car is short, around-town trips, the engine may never or rarely reach normal operating temperature when you drive the car, and not enough heat in the passenger compartment on a cold day is only one of the negative consequences. Low temperatures encourage incomplete combustion, which leads to poorer fuel mileage and carbon deposit build-up. Also, water inevitably gets into the oil just by condensation, and this water is boiled away without incident when the engine reaches operating temperature. If the engine never or rarely reaches this temperature, this water is not boiled away and builds up in the crankcase, leading to all kinds of problems with poor lubrication being only one of them.

Just like Goldilocks' third bowl of soup, which was neither too hot nor too cold, an automobile engine has a temperature range at which it was designed to operate. Too much above, or below, this range of temperatures causes problems.

 

I thank all of you. I drove again to tel aviv, and it went well. I was not too hard with the car. Usually it kept a normal temprature, but when i was climbing uphill back to jerusalem the engine was hotter. About the same as shown s on the first photo of the heat gouge. The electric fan was on with the mechanic one. It cooled down to normal when i drove in the city. I guess that this is the way it should be. Or i should be worried about the head gasket or fhe engine will fail if i keep driving this way?

 

By what? 1 degree? "Uphill" in your case is a negligible 1% grade. You could drive that all day long and your car would never notice it. No car would.

 

Thx januty. You helped a lot

 

I doubt it.

So how much DID the temperature rise? Were you driving at nearly 100 mph hour, too? You always give us only partial information.

If we're going to help you diagnose a problem or determine if you have a problem at all, you can't just make vague statements like "the engine was hotter" unless you tell us how much hotter (2 degrees? 10 degrees? 50 degrees?), exactly under what circumstances it got hotter (idling in your driveway? driving at 10 mph in city traffic? going 95 mph on a country road? -- you said it was when you were driving "uphill," but uphill means nothing in your situation), and what it rose from and to (190 to 210? 200 to 220? 200 to 250? 190 to 195?). A little temperature rise is likely ok, depending on the circumstance. A lot of temperature rise is probably not ok no matter what the circumstance.

Complete information is what we need.

 

O. K. Never exceeded 68mph on flat road. And while was driving uphill no more then 50mph. I was driving from 500 feet to 2500 feet in about 20 minute. No a/c. Outsisde temperature 82f. Electric fan on. The temperature went up the same as the first time, as shown on the photo, one line before the 250f, and went normal few minuts after i entered the city, two lines before the 250 . That is all i know. My question is: can i harm the engin at that temperature?

 

So what you're saying is normal highway driving conditions, very gradual elevation change, and the temperature, using the markings on your gauge, went from about 200 to about 225 and then settled back down. I wouldn't worry. You do not have an overheating problem. You really don't know how accurate that gauge is, anyway, and what temperature markings there are are 25 degrees F apart, which is very crude. That gauge is not designed to give you any kind of an accurate temperature reading. What it's good for is to let you know of a significant change in temperature, so you need to assume a starting point. In other words, you need to get the engine running properly, which apparently it is, and use the gauge reading when the engine is fully warmed up and idling as a base value. Then note how much it changes in normal driving as it will move up and down a bit depending on conditions, and be aware of any significant change in the base reading and the normal fluctuation while driving. If changes are observed, then look for a cause.

Remember, this car came from the factory with a temperature indicator light, not a gauge, and if all that was on the car was the indicator light, you would have no idea what the engine temperature was doing other than that it was low enough that the indicator light did not turn on. Without any other overt symptoms of overheating, and it doesn't sound like you have any, you would never have thought that the car might be overheating, and you wouldn't be worried about it now.

Sometimes too much information is worse than none at all.

Nice pants, by the way. Are those Levi's?

 

Case closed. I thank you very much. We don't have that serious forums in israel.

 

I don't know if i was wearing my levies then. I am now

 

We are deadly serious here at ClassicOlds.

Especially Jaunty.

I do have to agree with him, though: 225°F is not excessively hot for a long, slow, slightly up-hill drive at highway speeds on a warm day, provided that your cooling system is properly pressurized.
It is, right? Next time you drive and the car is fully warmed up, open the hood and squeeze the upper radiator hose - it should feel quite hard. If it's soft, you need to figure out where the leak is (radiator cap is always the first thing to check).

It IS possible to stop this temperature increase if you want to, by going to a larger radiator - if you have a 2-row, get a 3-row, and if you have a 3-row, get a 4-row.
Of course, you MUST have a properly functioning fan and shrouding to direct the air - we haven't seen that yet, so we cannot comment on it.

- Eric