212 *F normal engine temp?

[Robroy]

My newly installed temp gauge shows 212 *F (100 *C) when the engine gets warmed up. It seems to stay there, could go up to like 220 *F (105 *C) when standing still idling.
With pure water in the system it would boil :eek: , no question about that. I have however plenty of anti-freeze, probably maximum (50%).
Now to my question, those of you that have temp gauges in your cars, what do they normally show? And what is considered to be the normal operating temp for a 455?

According to the 73 Buick service manual the “Hot engine” warning light comes on above 246 *F (118 C)and after 265 *F (129 C) the “Stop engine” light also comes on. After reading those lines 212 *F suddenly doesn’t feel so dramatic anymore….or?

Any input on the subject is much appreciated :user:

[centurion 455 ragtop]

Per

I will answer this one from my own experience after owning a 73 Riveiera GS and my Centurion, both towing and not. The 212 degree is on the warm side leaving not much room for those 90 degree plus days being stuck in traffic with the air on. :shocked: You may very well see 220. And once you stop she may boil over a bit.

I went for a new replacement 4 core radiator, installed a 140 thermostat. In the summer it will warm up fast, and being I don't drive in the late fall or winter I felt no need for a 195 stat which I think is recommended in the book. I then installed a Black Magic electric fan (need it for towing). I did have to remove the 2 front cross brace bars on the radiator support to make it fit. I tried keeping the clutch fan, even installed a new, but while towing on the highway the temps creeped up above 210, so I located a factory Buick fixed blade fan, it worked and does make noise but it's not very loud like a flex fan. I hate the flex fans and do not recommend them, they are noisy and they do on occassion fly apart (I had that happen with my K5 Chevt Blazer, that's another story). I would stick with the factory clutch fan unless you plan on towing.
Anyway the test was actually last summer. Towing with the air on the temps gauge hit 200 and stayed there. (we won't comment on gas mileage:( ). Not towing with the air in the summer it stays around 190-195. I have yet, even in traffic, with the air to hit 215.

My Advise,
1. Check your radiator cap and replace it. It is cheap and can't hurt. While your at it check all hoses and clamps.

2. Then make sure you have the correct mix of antifreeze. Too much like too little antifreeze and you can still overheat or run hot. You can find the coolant gauge that tells you your mixture in most auto parts stores, and they are not expensive.

3. Next check your thermostat. It may be shot. They are cheap enough and easy to replace. I would install a 160 or 175 degree one. I am sure the factory recommends a 195 degree stat. Most important: If you remove the thermostat, be VERY carefull on the two bolts, not to strip them. If they are tight or stuck don't force them. They may have to be heated with a butane torch to loosed the corrosion up on the threads. When you re-install the two bolts, put some anti-sieze compound on the threads. DO NOT OVER TIGHTEN.

4. As for the fan, I would stick with the factory clutch fan, you may want to first inspect it for oily grease on it (then its may be leaking). Or just replace the clutch assembly with a new one. The clutch fan works by spinning like a fixed fan under lower rpms and lower engine temps and when the engine reaches proper temps it almost free wheels. So it the clutch is bad it will not spin the fan as fast at idle or low speeds, the results will be warmer temps at lower speeds. On the highway it is designed to almost free wheel spin with little restriction.

4. Check your radiator. Make sure your radiator is NOT out of allignment. If it is pitched foward or backwards just slightly the incoming cool air can be restricted. It may also have to be removed and boiled out to remove any corrosion that is blocking the tubes. You may want to try to flush it out with a flush kit. It is fairly easy to do. Otherwise if the radiator does not seem good, a replacement one would be a huge help. I would do this last as it is the most expensive, unless it is obvious that you need one.

Last Note: Not knowing the enviomental rules, (tree hugger laws:laugh: ) you may not be able to flush out the radiator as the old stuff and cleaning chemicals may have to be recylced. Also not sure on car inspection. In New York State there is no emmission or polution equipment control tests on cars older than 15 years. It is just a safety inspection for $15 bucks. A lower than factory thermostat may make the car run richer on warm up and if you are subject to emmissions tests it may fail on a cold running test. So then you would have to change it back when inspection times comes up.

[centurion 455 ragtop]

Not to hijack the thread but this one is a story on overheating.

Back in the late 80's I was towing back from the GS Natioanls in Kentucky with my 1977 Chevy K5 Blazer. Well somewhere in western PA I heard a few cracking noises. The next exit we got off and the temp gauge pinned itself and the radiator was steaming. Into a warehouse parking lot we pulled.

Inspection: The flex fan had three blades fly off! It tore threw the radiator and the lower radiator hose! SH1T! Here we were 9 hours from home on a Sunday afternoon (stores are all closed). What to do!

I looked at my 1970 GS on the open trailer and thought...its gotta work. We pulled the Buick radiator out, and took the flex fan off too. Removed the Blazer radiator and lower hose. Had a spare hose (always carry spares). We used plastic zip ties to mount the radiator because it was way to big in width. Installed the lower hose and the flex fan.

Now the kicker....where to get water...The tow car was drained of water after racing, so....:rolleyes: we took the cooler along with three six packs of canned Coors beer....YEP :xyxthumbs: poured it into the radiator along with the melted ice from the cooler. :beers:

We were back on the road within 2 hours and made it home with no problems! That my friends is a true story for the books.

Always remember on long trips to take a good small tool box, small hydraulic jack, gallon of mixed water & anti freeze, a spare water pump, fuel pump, hoses & belts (2) quarts of oil and (2) quarts of trans fluid, first aid kit and fire extinguisher, duct tape (you would be surprised) and hi temp silicone, don't forget a funnel. Oh and some plastic zip ties And for us convertible guys, those extra convertible top cables, motor and relay too.

Needless to say that was the last time I would EVER use a flex fan again.

[Robroy]

THANKS Rick for the list of good advice as well as that entertaining story :laugh: , a few six packs always come to good use! :D

I will order a new thermostat and radiator cap tomorrow and do a check on the clutch fan and radiator allignment.

I have the kind of coolant gauge that tells the freezing point, maybe I could figure out the mixture buy using that…

While I owned my car I have never noticed any sign of boiling although I was surprised how quickly that big engine got warm and how hot it can get inside the car with the heat on.

Radiator looks fresh on both inside and outside, water pump looks like replaced not too long time ago. All hoses and clamps look good as far as I have seen.

[Robroy]

Went out and had a look in the garage, radiator alignment looks ok as far as I can see. Tried spinning the fan and it moved like half a lap, don’t know how much resistance to expect?
Since the temp stayed the same driving as standing still would mean the fan is working properly I guess….

[EEE]

My car used to run around that, and it would go up to 220-230 when sitting still in traffic on hot days. This would be a problem if you turned the car off, and then tried to re-start it, it would barely turn over. I think it got fixed when I changed the thermostat.

[centurion 455 ragtop]

One last thought. If the timing is advanced too much, you may like it as the performance increases, but the trade off is the car will run hotter, and the hot starts will be tough slow cranking.

[Robroy]

My car used to run around that, and it would go up to 220-230 when sitting still in traffic on hot days. This would be a problem if you turned the car off, and then tried to re-start it, it would barely turn over. I think it got fixed when I changed the thermostat.I have my hope on that a new thermostat will do the trick too; do you remember what temp it was on the one you installed?

[Robroy]

One last thought. If the timing is advanced too much, you may like it as the performance increases, but the trade off is the car will run hotter, and the hot starts will be tough slow cranking.
My timing is like 4*, just by the book. I have been looking forward to mess with it though to get a little extra punch as well as a better mileage since I run 95 octane, gone replace the pointers with a Crane-unit as well as the springs for the weights, new coil, new wires and plugs.
I guess all that fun will have to wait now :bawl:

[The German]

Rick, I also thank you for all this detailed information. It could be of good help for everyone of us in case of problems with our engine cooling system and - better - to avoid such problems.

Big thanks for spending your time to give us this volume of special information here and in some other threads too !! You are a good teacher, Rick, especially for us "green horns" (new vintage Buick owners). I (guess I could say we all) really appreciate that very much ! :xyxthumbs:

[centurion 455 ragtop]

Thanks Rolf, I like to think of this board with fellow Buick guys as an extended family.

One other thought with the timing. By advancing it up beyond the factory settings you will gain performance like I said, BUT you will most likely need to run a higher octane fuel. She will ping under load with the timing up there. And I know gas here is at $4. and more for the higher octane, Lord knows, you poor guys across the pond getting hammered at the pumps especially for the high octane stuff.

[EEE]

I think the thermostat I installed was rated at 180f, but I'm sure someone else here would have a more precise answer to what to use.

[Robroy]

I just ordered a 160 as well as a 180*F thermostat and a new radiator lid.

What do you guys think, can you run the engine warm with the radiator lid off without getting coolant all over the place? I’m thinking on measuring the temp on the coolant with an ordinary thermometer just to check how correct my new temp gauge is.

Also just heard that some gauges may need to be calibrated which in such cases can be done with a set screw on the back on the gauge, need to find out if mine is that kind…:rolleyes:

[centurion 455 ragtop]

I just ordered a 160 as well as a 180*F thermostat and a new radiator lid.

What do you guys think, can you run the engine warm with the radiator lid off without getting coolant all over the place? I’m thinking on measuring the temp on the coolant with an ordinary thermometer just to check how correct my new temp gauge is.

Also just heard that some gauges may need to be calibrated which in such cases can be done with a set screw on the back on the gauge, need to find out if mine is that kind…:rolleyes:

What you might want to do before you change anything.

1. Work with the car being cold it had not been running.

2. Remove the cap (lid) and just top off (fill up) the radiator with water so that it is about an inch or so from overflowing. Also fill the overflow to proper level.

3. Start the car. And watch the fluid level and movement in the radiator. If the level drops then re-fill it up. It shouldn’t though. You should see little to no water movement in the radiator. Once the temperature rises to the thermostat temperature setting, the thermostat will open. You should then see the water level drop a bit and most of all, water movement. This will indicate to you it opened and the water is at the thermostat temperature. Before doing anything else just watch it. Because once it opens the cooler water in the radiator will now pass into the engine and the thermostat may close until that water is up to temperature again. If your water level drops a lot re-fill it so that you can see it and reach it with an external gauge.

4. Once you see the constant movement stick in a thermometer or temperature gauge. And check your readings.

That is far as I would go. Once you do that re-install the radiator cap (lid). If you happen to turn off the engine with it off you will get some overflowing.

This test will at least tell you the thermostat is working. If you get a good reading on your thermometer it should be what the thermostat setting is at.
I would not worry if it is slightly off between the two also compare it against your temperature gauge inside the car.

As for the gauges being calibrated. In the past I have just bought some good brand name gauges. Always remember you get what you pay for. Cheap gauges and you will get cheap crapping results. You don't have to buy exotic oil filled gauges, just make sure they are of a good brand name.

Per, start with the easiest and cheapest tests and try them out before going to the next step. If you change everything at once you may never know what was the cause. Once you check the coolant mixture and replace the cap and doing a visual inspection, including the above test, take the car out for a drive and get stuck in some slow traffic, try to get the temps up on purpose. Also keep a note of what the gauge says. After a nice test ride park it and leave her running. Pop the hood and turn off the engine. If you get engine run on, you either got poor octane gas, the car is running way too hot or the timing is too advance. If she shuts down with no complaints, observe and listen over the engine. If you’re running real hot close to a boil over, you may hear some bubbling. If you do, a problem still exists. If all is quiet, you may have solved the problem.

If not, next step is to change the thermostat and flush out the coolant system. Then do another test drive with a look and listen again.

[Robroy]

What you might want to do before you change anything.

1. Work with the car being cold it had not been running.

2. Remove the cap (lid) and just top off (fill up) the radiator with water so that it is about an inch or so from overflowing. Also fill the overflow to proper level.

3. Start the car. And watch the fluid level and movement in the radiator. If the level drops then re-fill it up. It shouldn’t though. You should see little to no water movement in the radiator. Once the temperature rises to the thermostat temperature setting, the thermostat will open. You should then see the water level drop a bit and most of all, water movement. This will indicate to you it opened and the water is at the thermostat temperature. Before doing anything else just watch it. Because once it opens the cooler water in the radiator will now pass into the engine and the thermostat may close until that water is up to temperature again. If your water level drops a lot re-fill it so that you can see it and reach it with an external gauge.

4. Once you see the constant movement stick in a thermometer or temperature gauge. And check your readings.

That is far as I would go. Once you do that re-install the radiator cap (lid). If you happen to turn off the engine with it off you will get some overflowing.

This test will at least tell you the thermostat is working. If you get a good reading on your thermometer it should be what the thermostat setting is at.
I would not worry if it is slightly off between the two also compare it against your temperature gauge inside the car.

As for the gauges being calibrated. In the past I have just bought some good brand name gauges. Always remember you get what you pay for. Cheap gauges and you will get cheap crapping results. You don't have to buy exotic oil filled gauges, just make sure they are of a good brand name.

Per, start with the easiest and cheapest tests and try them out before going to the next step. If you change everything at once you may never know what was the cause. Once you check the coolant mixture and replace the cap and doing a visual inspection, including the above test, take the car out for a drive and get stuck in some slow traffic, try to get the temps up on purpose. Also keep a note of what the gauge says. After a nice test ride park it and leave her running. Pop the hood and turn off the engine. If you get engine run on, you either got poor octane gas, the car is running way too hot or the timing is too advance. If she shuts down with no complaints, observe and listen over the engine. If you’re running real hot close to a boil over, you may hear some bubbling. If you do, a problem still exists. If all is quiet, you may have solved the problem.

If not, next step is to change the thermostat and flush out the coolant system. Then do another test drive with a look and listen again.
That sounds like real good advice to me and I truly appreciate your interest in my “case” Rick! That’s one of the great things with this site that we can help each other by sharing experience and knowledge to crack problems as well as finding parts :beers:.

My triple gauge set was like 100 dollars, far from premium quality but still good enough I hope. I will follow your advice and start her up with the lid off and observe, and then measure temp before rushing into doing a lot of changes.
I hope to get on this tomorrow evening since there’s a big car show/cruise for American classics this Saturday in my hometown that I’ve been looking forward to. I’m going there either way but was hoping to bring the Centurion.
It’s been a busy week in general for me since I have been entertaining two American colleagues/friends that’s on visit here, we’ve been out pretty much every evening :D:beers:

[73 Centurion]

A couple of fun cooling system facts:

1) A typical water antifreeze mix will boil at 220-230. Anti-freeze lowers the tempurature at which the mix freezes, but it doesn't raise the boiling point much.

2) Each pound of pressure raises the boiling point around 3 degrees. So that simple little 15 pound radiator cap raises the boiling point around 45 degrees.

3) That's all at Sea level, as you go up in altitude the boiling point goes down, so a little trip to the mountains could cause a problem for a marginal system.

The hot engine light comes on at 245 degrees, but a good working cooling system will be OK. The stop engine light (I've never seen that one) comes on at 265 because you're about to exceed the boiling point (220 + 45 = 265).

Any weakness in the cooling system will turn into a geyser when you pass 230.

If your cooling system exceeds the boiling point and you remove the pressure from the system it will shoot out a nasty mix of steam and liquid that will ruin your day. Remember the temp varies throughout the system. A hot spot in the engine can easily exceed the boiling point and if you release the pressure it will turn to vapor and shove anti-freezer out any opening.

That little rubber gasket under the radiator cap is worth about 45 degrees of insurance against boiling over. It should be checked at least once per year and replace the cap if the gasket starts to harden.

So a properly working system will be fine at 212 but you're at the upper end of the range.

John.

[Robroy]

Thanks John for adding these very interesting facts!

This evening I had the car stand and idle out on the driveway with the radiator lid off. The Radiator was pretty full even as cold and during the whole test a little coolant spilt out every now and then. After a few minuets the gauge inside the car showed 122 *F ( 50* C). A little later the upper radiator hose started to feel a slightly warm and I could see small movements in the radiator, I then started to measure the coolant in the radiator with a digital thermometer. First I got 116 *F and later 131*F, then it went down again (just as you predicted Rick) and then up to 143 *F. Then it started to swing between 125-142 *F. I was never able to measure any higher than 143 *F in radiator and I had the engine running for 20 minutes. The gauge inside the car stayed steady at 206-212 *F except for a short while when it went up to 230 *F for maybe 30 sec and then it went back to 212 again.
Outdoor temp was 70 *F this evening. After I switched the engine off I held the thermometer against the brass fitting on the intake (metal to metal) and got 180 *F.

What conclusion can be made from this? To me it seems like the thermostat might not open fully and also as I might have purchased a crappy temp gauge (inside the car)?
Think I’ll go ahead and replace the thermostat, need to decide to go for 160 or 180 though…:confused:..and I will also replace the radiator lid since I have a new one anyway (16 Lb).
Thoughts?

[centurion 455 ragtop]

What conclusion can be made from this? To me it seems like the thermostat might not open fully and also as I might have purchased a crappy temp gauge (inside the car)?
Think I’ll go ahead and replace the thermostat, need to decide to go for 160 or 180 though…:confused:..and I will also replace the radiator lid since I have a new one anyway (16 Lb).
Thoughts?


After you replace the thermostat, DO NOT throw out the old one. Take it inside get a pot of water on the stove and place the old thermostat inside it. Wait and watch until it starts to open and take the temp of the water. When it fully opens take the temp again. At least you can see if the thermostat was working properly. If it is the work was not wasted, at least you installed a fresh one that you know will be working. The problem child may very well be the gauge.

Remember do not force those two bolts on the thermostat housing if they refuse to be removed. Use heat to loosen them if they are jammed.

Clean the housing and where it mounts very well before you re-install otherwise it will leak.

Can't hurt to use a small amount of silicone sealer on the gasket and anti-seaze compound on the bolt threads

The book calls for only 20 pounds on a torque wrench to tighten them up. You don't have to use one, but just remember not to muscle the bolts too tight, you will strip the threads.

The book also calls for a 15 pound radiator cap, your 16 pound cap should be good enough. Factory thermostat is 190 degree, I would use a 180 instead.

[The German]

Per, I´m still far from being an expert in car´s mechanics - you know - but in this case one can only think logical and here are my thoughts:

1.) The difference between the digital thermometer and the gauge was too great, so I´m sure that you have to adjust or replace the gauge anyway. That´s why I would do this in a first step.

2.) The thermostat opens with increasing temperature; that means it opens slowly and the cold water goes into the engine´s hotter water cooling it down so that the thermostat will hesitate to open further for a while. You measured the temp. during engine idling only, so the temp. came not to significant higher level which probably would have opened the thermostat full. 180°F measured at the engine´s metall shows that this could be the reason. On the other hand you saw that the thermostat opened early enough, so that here could not be a problem. That´s why I wouldn´t change the thermostat at this time. I would first test how temperature would develope with the correct gauge when driving the car in normal traffic on a higher temperature level. If temperature would rise higher than normal (let us say higher than 205°F [96°C]) I would start thinking about starting a next step ! And I guess this level for such a decision could be a little bit higher than 205°F - guess start the next step if temp. would reach 212°F [100°C] would be on the sure side also.

So based on your measurements I´ve got the impression that your cooling system could be okay, only the gauge seems to be not what it should be.

Probably you could save money and time and enjoy driving your blue giant instead working at.
BTW: I still have the nice pic of your car from the calendar on April´s page in my mind; - for me it was like a window to spring time because we had cold and rainy weather during the first weeks of April and your blue giant was to be seen in bright sunshine in front of a sun-color-yellow painted house with some little green bushes - the right picture at the right time for me !:)
(Now we have Rick´s car at a car show for this month, which is the time when the car shows season starts - also placed to the right time.) I love this calendar, but that´s another story ... .

Hope the things will clean up for you, Per, GOOD LUCK ! :xyxthumbs:

[Smartin]

THe coolant in the radiator will probably not read as hot as the coolant in the intake, so I would guess that your gauge is correct.

[The German]

The coolant in the radiator will probably not read as hot as the coolant in the intake, ... ...

I´m sure that there has to be a difference, but isn´t it a pretty high diff. what Per measured ? And he measured 180°F at the metal of the intake which couldn´t have such a difference to the coolant temperature only half an inch behind the wall; as we all know temp. goes through metal very good ! ===>?:rooleyes2:

[Robroy]

I´m sure that there has to be a difference, but isn´t it a pretty high diff. what Per measured ? And he measured 180°F at the metal of the intake which couldn´t have such a difference to the coolant temperature only half an inch behind the wall; as we all know temp. goes through metal very good ! ===>?:rooleyes2:
That’s what I thought too, the difference in temp between radiator and intake feels like a bit too much (68 *F). Since the water pump looks replaced not too long ago, circulation should be ok, so I suspect the thermostat is not operating properly.

Thinking on testing my temp gauge (inside the car) by removing the sender unit on the intake and then put it in a cup of water that just came from a kitchen water boiler. Then put the digital thermometer in the same cup and match the reading on the thermometer with the gauge. That should tell how correct it is I think...

[The German]

... ...Thinking on testing my temp gauge (inside the car) by removing the sender unit on the intake and then put it in a cup of water that just came from a kitchen water boiler. Then put the digital thermometer in the same cup and match the reading on the thermometer with the gauge. That should tell how correct it is I think...

Guess that´s a good idea, Per !

[Robroy]

Just installed a brand new 180 *F thermostat. It was a 195 *F that sat there.
Followed Rick’s advice regarding the threads where the bolts go in. I let the bolts go in and out several times to release the dirt and then used compressed air to clean the bolt holes. Put on some cooper grease and tightened with a prayer.
Tomorrow I’m gone do the gauge test (post 22) and then fill up the system with coolant again, and if everything seems working allright, I’ll then go on a car show with 900 other American classics :beers: :)

[Robroy]

A new thermostat (180*F) and radiator lid really made a difference!
When I did the first test run the gauge stopped at 176*F (80*C) as the thermostat probably opened full there. Went down to the gas station to fill her up and had the engine running since my battery was pretty weak. Bumped in to an old school mate there and before I took off the car had been standing idling in the sun for about 10 minutes and the gauge was now up at 194*F (90*C). I then headed for the car show and the gauge kept at 194*F (90*C) and after like 20 minutes it reached 203*F (95*C) where it stopped. Yesterday was really hot (78*F) here for this time of year so I still feel pretty ok with 203. When I drove back home late in the evening the gauge stayed steady on 180*F (82*C) all the way, outside temp had then dropped to 55*F (12*C).

I did do that gauge check too with the sending unit hanging down in a cup of newly boiled water together with the digital thermometer. There was a diff on 5*C which could be expected with a little margin for error on them both. It was a bit tricky since I had to ground the sending unit with a piece of jumper wire and at the same time hold the thermometer as well as the sending unit.
Conclusion is that the gauge is not super exact but fairly correct as could be expected for the price I paid.

I want to thank all of you who helped me to crack this! Your friendship really adds an extra dimension to this hobby of mine. :beers:

[centurion 455 ragtop]

Any time Per. Thats what this is all about:xyxthumbs:

[The German]

:xyxthumbs::xyxthumbs::xyxthumbs:

I´m glad that this story ended without greater problems for you, Per !

Enjoy your car ! Hope we´ll get a real summer this year, but the start is promising - in Germany we have the 2nd week without rain now (Centurion-weather :D) !