Just looking for some opinions; is it a good idea to install an aftermarket water temp gauge in my 61 Olds 98, or just keep the HOT COLD lamp working on it from factory? It has been known to overheat in warmer, slow moving conditions. Installed an electric fan for now when such occasions arise. The HOT lamp would come on at about 245° F. Thoughts?

 

If it's prone to overheating, it's a no-brainer to install a good gauge. If my engine was overheating, I'd want to know well before 245°.

 

I agree that I'd want to know before 245* if my car was running hot. Make sure you get a quality gauge.

https://www.autometer.com/

 

Gauges and add-on fans are just bandaids. The real problem is why the engine gets to 245 degrees in the first place. Certainly being in hot summer traffic was not unknown when the car was new, yet these cars didn't need gauges or add-on fans then. What is the condition of the cooling system? Etc. Track down the underlying cause of the problem.

 

Has the car puked coolant from the radiator during these supposed overheating conditions? I say supposed, since if you're not puking coolant it's likely whatever device you're reading/measuring coolant temp. is faulty.

 

IMO it's always a good idea to have a temp gauge and know how hot it's running......before it pukes coolant. I wouldn't trust the dummy light.

 

Been chasing the overheating for a while. A good block flush should help, I think it seems to be a flow issue, either air flow through the rad, or coolant flow when it gets warm and is idle in traffic. As soon as I get moving, she cools off. I have had a temp gauge before but wanted to not “worry” so much and constantly eyeball the gauge. I figured I would pull over IF that red warning lamp ever came on. Another owner of an Olds at Back to the 50’s here in MN, seemed to think those 394’s ran warm, even his restored 62 Olds 98 rain up into the 230’s he said.

Side note, it does not have the original rad, it was replaced before I took ownership of the car with a slightly smaller (there is about a good inch to one side of the rad, with about 1/2 inch on the other) aluminum rad in it.

 

I agree with Jaunty on the fact the car functioned without and electric fan when it was new. I don't agree on the gauge since that just gives you better info. I am not familiar with the car and don't know if it has a clutch on the fan or not. If so, that would be one of the first things I would check.

 

I haven't reviewed any other/previous posts you may have provided regarding overheating conditions; yet, 'generally' speaking if it doesn't overheat while driving (when airflow is optimal) but overheats at idle, persistent/repeated stop & go conditions, and especially after engine shut down, my first suspicion is a failed radiator cap - regardless if it is new.

 

there is no clutch on the fan. It is a four blade fan.

 

A six blade fan might help. I would do that before I would do an electric fan. Just because it came with a four-blade van does not mean it can't be improved upon.

 

tried that one did nothing for it at idle and hot slow driving conditions

 

That is a classic symptom of insufficient air flow, assuming everything else is operating correctly, such as the ignition system. Retarded ignition timing can result in overheating at low engine speeds.

 

Running warm and overheating are two different things. People seem to think that cold is good and colder is better, but it's actually the opposite as far as engine efficiency. Combustion is more complete the higher the temperature. A engine can run at 220 or 230 all day long without it being the indication of a problem. Coolant boils at about 250F. While I would get uncomfortable as well if the temp approached much over 230, I wouldn't worry if it stayed below that.

My parents gave me the use of a '75 Chevy Nova (250 inline 6) when I was in college starting in 1976, and one of the first things I did, just for the fun of it, was put a temperature gauge on it. Not because it needed one. Heck, the car was only about a year old. But putting in gauges was something that 20 year olds did. I didn't know what the "correct" temperature should be because all there was was a dash light. But I assumed that, since the car was running fine, I could treat whatever the gauge came to the first time it registered a temperature when the engine was fully warmed up as normal and only be concerned if the temperature ever got much above that.

Well, the gauge immediately went to 220 and stayed there. I drove the car for the next ten years, and the temperature never varied from 220 plus or minus a degree or two. An engine running at 220 would probably give many people on this site apoplexy, and for no reason. My engine was perfectly fine.

One thing I've observed here many times is people putting a temperature gauge in their cars and ruining their lives in the process. The car was running fine, and, before the gauge, all there was was the dash light. It never went on, the guy never worried about his engine's temperature. But then he puts in the gauge, and suddenly he's miserable. He watches the gauge constantly, conscious of every nanometer-sized movement of the needle. He worries constantly. "It it getting too hot?" "The needle moves a bit up and down as I drive the car up and down hills and so forth" Etc. Etc. Etc. It begins to affect his life. He suddenly can't sleep any more. His marriage crumbles. His kids will no longer speak to him, too embarrased to bring their friends home since the "crazy person" might be in the house. Eventually he seeks psychiatric help, and the doctor says to remove the gauge. The guy does so, and suddenly life is beautiful again. His wife comes back to him. His kids talk to him again. He takes the car to the golf course and plays a round without ever once thinking about what the gauge might do on the way home.

There's an old saying that ignorance is bliss. There's lots of truth in it.

 

While they are quite drastic, your effects of a guy installing a temp gauge of very humorous.

 

If the radiator is smaller than the original, and there is a gap around it, that’s probably a big part of your issue.

Any air that goes around the radiator instead of thru it is wasted airflow. Either get the correct size radiator, or fabricate something to fill in the hole.

Are all the factory baffles and tar paper shields there? Those are designed to help force air thru the radiator instead of around the engine compartment.

I personally like knowing exactly what my drivetrain is doing and its current status. Put a good quality set of gauges on it, and frequently look at them. Don’t freak out at the readings unless they indicate an obvious problem. Look at them often enough to get a feel for what’s normal, in all situations. Then if the gauge suddenly reads differently than the expected normal, you know something isn’t right.

I wouldn’t be too concerned with 220-230 at low speeds. Especially since it cools down immediately when you start moving. Seal the radiator to the core support, install a factory fan shroud, and maybe a thermal fan clutch with bigger fan, and I bet that will eliminate your concerns