1959 overheating going uphill

[Joshua]

Good Afternoon Everyone,

Just finished rebuilding my transmission and I have successfully road tested it.  However, when I go up a prolonged hill (Cajon Pass - a fairly steep grade in Southern California) the engine will begin to run very hot (up to the 3/4 mark).  The engine was rebuilt and has about 750 miles on it.  All of the hoses were changed and the radiator was rodded out.  The heater core was also replaced as well as a new water pump installed.  All new clamps and gaskets.  New thermostat (160 as per the shop manual).  Factory 7 blade fan, fan shroud, and rubber "cover" at the top of the radiator support bar.

The entire time I was on flat ground, I had the factory air conditioning running and I was doing around 70mph.  As soon as I hit the hill, the engine began to go past the 1/2 way mark, I first turned off the air conditioning.  When the temperature kept climbing, I slowed down to 55-60mph.  This helped a great deal and then temperature slowly dropped to the 1/2 way mark.

I turly do believe that the cooling system was designed to work without the aid of any additional equipment or modifications. 
Have I missed anything?
Has anyone else experienced this?
I really do not like the idea of an electric cooling fan, but has anyone had any success with one?

Thanks in advance for any advice,
Joshua Cross

[Steve W]

I just had my radiator re-done by a very cool, old-school guy in Burbank. (I thing Burbank is a High-holy place for us old car buffs!). He saved the tanks and put in a brand new core...now NO overheating issues even during this heat wave we are having in the SF valley! Never goes more that a HAIR past the 1/4 mark, even with ac on full-blast and me doing 80 uphill!

I don't know what "rodded out" means.

Also..check your timing. Bad timing will make the engine run hotter. Are you pinging going uphill?

I changed to pertronix and ditched the points, had my distrib re-built too.

New fan clutch, water pump, hoses, t-stat, etc.

Before doing all that stuff to my car, it would normally run at 1/2 and get up to 3/4 on a hot day. And it ran hotter the faster I went!

Now...no issues at all!

[Jon S]

I had my radiator rodded several years ago and the gauge never exceeds 1/4. I suspect there is rust or something in your coolant preventing good circulation. Also, are you running a 50/50 mix of anti- freeze to distilled water?  Take a look at the anti-freeze and see how it looks. I find Peak brand flows the best.

[Jeff Rosansky CLC #28373]

One thing often forgotten in a case like this is vacuum.
A prolonged uphill run will take more throttle which will reduce the vacuum. Short bursts are one thing but a long steep hill will deplete the reserve tanks.
No/low vacuum means no vacuum advance so the timimg will be retarded which will make it run hotter.
That may not be the answer but at least worth exploring.
Jeff

[Scot Minesinger]

Also, how is the exhaust system?   What you wrote seem characteristic of this issue.

When you burn a lot of fuel, it has to be expelled thru exhaust.  Many an overheating  problem has been caused by restricted exhaust which really show up during heavy use of fuel.  This is often the subject of "ask the mechanic" sections of car magazines..."car runs hot at 70mph, then slow to 50mph and it cools down..."  To test this put a tee in the manifold vacuum with hose and vacuum gauge, the vacuum should decline if exhaust is plugged.  This also ties into what Jeff wrote about vacuum negative impacting timing (retards it and runs hotter), becomes a catch 22.

[walt chomosh #23510]

Josh,
  I'm with Jeff Rose on this one....motor timing. The vacuum advance diaphragm should be checked for proper operation, not to mention base timing.....walt...Tulsa,ok

[David Greenburg]

I suggest getting an infrared thermometer so you can see where the hot spots are.  Especially with the new radiator there should be a big drop in temp between top and bottom of the radiator.  While not common, I was also recently victimized by a rebuilt water pump that failed internally; the impeller separated from the shaft.  There was no noise and no leaks, so no one suspected it.  With a new 4 row radiator, my car never gets above the 1/4 mark, regardless of weather, traffic or use of a/c.

[Steve W]

What is "rodded" or "rodded out"?
From the term, it sounds like it means having the tubes somehow cleaned out with some type of rod?  But doesn't that still leave some corrosion somewhere in there?

Maybe it's just me, but if I had a '59 (one can DREAM, can't they?) and I re-built the motor and transmission, I would have a re-cored or new radiator installed for maximum efficiency!

And, yes, it seems like whatever the cars had on them when they were new worked just fine!  It's just that over the decades, some of the components wear out or get clogged up,  and a lot of replacement parts get added and modded to fit. And, honestly, I was thinking about electric fans/different radiator combinations, etc before having my radiator re-cored. Glad I didn't go through all that stuff!

And correct timing is essential!

[Jeff Rosansky CLC #28373]

If the car is nice and cool under normal conditions, and it only heats up when going uphill and better when flat, then something with the hill has to be the culprit.
What happens when you go up a hill? Yes the engine works harder, but not that dramatically more......... You have the throttle opened wider than normal for a longer period of time.  what happens when the throttle is open wide? This is what you have to ask yourself.
The reason I think vacuum is that we know when the throttle is open the vacuum goes down. No problem when it is only a short burst. But a long hill will bleed down the accumulators so the entire system loses vacuum.
That is my thinking on the earlier post.
Jeff

["Cadillac Kid" Greg Surfas 15364]

Joshua,
I would check the vacuum advance module (canister) and verify it is working and that the vacuum lines to it are leak free.
Greg Surfas

[The Tassie Devil(le)]

What is "rodded" or "rodded out"?
From the term, it sounds like it means having the tubes somehow cleaned out with some type of rod?  But doesn't that still leave some corrosion somewhere in there? 

Rodding out is where the top and bottom tanks are removed, and the operator uses a "rod" as in a flat strip of steel that fits through the coolant tubes, and physically removes any gunk that is blocking the tubes.

And yes, if there is gunk in the radiator, then there is likely to be gunk in the water jackets inside the block/heads.   This can be cleaned out by removing the welsh plugs, and poking around inside the block with a wire to dislodge that stuff.   Then wash that out.

Bruce.

[55 cadi]

If you want to make sure it doesn't clog again,  look at my post about clogging radiators. In General discussion

Quick note, google "gano" filter

I used it and works great, and then remove and replace hose when nothing else is running through.

Jason

[Glen]

Before doing anything drastic with the radiator check the lower radiator hose.  I know you said it was replaced but did the replacement have a “spring” in it?  The “spring” is to keep the hose from collapsing under the suction.  Those springs rust out and sometimes they are missing in new hoses. 

It is easy to check.  Just squeeze the hose by hand.  If you can squeeze it or any part flat, that maybe your problem.   

[V63]

A few other suggestions:

FAN CLUCH. I do not trust them since we had a very bad relationship once! I opt for a 'flex' fan every time! Many flex fans  sold off the shelf are too aggressive, noisy. Cadillac offered them in the 70's and I love those versions.

FAN BELTS: don't forget they DRIVE  your cooling system!

LEAN FUEL MIXTURE: a lean enough fuel mixture can cause over heating!

BRAKES: could your brakes be dragging? I place my hands on all the wheels to feel for excessive heat after an extended drive. Very good practice with trailers at every fuel stop.

GAUGE: are you getting symptoms of overheating other than your gauge, sometime the original equipment should be thought of as 'Just a suggestion', temporarily install an aftermarket gauge until issue is resolved

TRANSMISSION: could this be related to your transmission rebuild? Monitor your fluid for discoloration and odor.

PRESSURE: Verify your cooling system against pressure leaks.

COOLANT: remember that water alone is the best coolant! Antifreeze is a necessity, however some people think 100% coolant is better to eliminate corrosion. This is not a good idea.
50/50 is generally accepted.

[55 cadi]

V63,

Dont you mean water alone is "NOT" the best coolant

[Bobby B]

V63,

Dont you mean water alone is "NOT" the best coolant

No,
He's right. Water is the best coolant. Way better heat transfer than coolant, or when mixed with coolant. Problem is that most of us have to deal with some form of freezing temperatures and you would still need a lubricant for your water pump.
                                                                                                                                         Bobby

[55 cadi]

Wow 

Ok, I have always been told to not do all water because if it starts heating up once it starts to steam or boil it happens fast to most of it and you loose a lot more at a faster rate.

This and then the battery thing, I'm questioning if anything i know is true.

[76eldo]

The water only thing is a myth.
Many years ago I replaced a water pump on one of my cars and the radiator too.
I figured I would text the system by driving it to work on straight water and if there were no leaks I'd put the antifreeze in it the next day.

It overheated.

A 50/50 mix is best. It's coolant and antifreeze for real.

Brian

[Bobby B]

The water only thing is a myth.
Many years ago I replaced a water pump on one of my cars and the radiator too.
I figured I would text the system by driving it to work on straight water and if there were no leaks I'd put the antifreeze in it the next day.

It overheated.
A 50/50 mix is best. It's coolant and antifreeze for real.

Brian,
   Straight from the Redline Website:
Water has amazingly superior heat transfer properties compared to virtually any other liquid cooling medium - far superior to glycol-based coolants. As shown in Table 1, water has almost 2.5 times greater thermal conductivity compared to glycol coolants. Mixtures of glycol and water have nearly proportional improvement due to the addition of water. Most heat is transferred in a cooling system by convection from hot metal to a cooler liquid as in the engine block or from a hot liquid to cooler metal surfaces, as in the radiator. The convection coefficient of liquids in a tube is a complicated relationship between the ther- mal conductivity, viscosity of the liquid, and the tube diameter which determines the amount of turbulent flow. Since 50/50 glycol solution has about 4 times the viscosity and only 70% of the thermal conductivi- ty of water, the thermal convection coefficient for a 50/50 glycol solution is approximately 50% of the coefficient for water. Water in the cooling system is capable of transferring twice as much heat out of the same system as compared to a 50/50 glycol coolant and water solution. In order for a 50/50 glycol mixture to reject as much heat as water (amount of heat rejected is independent of the coolant), the tempera- ture differentials at the heat transfer surface must be twice as great, which means higher cylinder head temperatures.

Would I use use straight water in my own car? Absolutely not....Unless I wanted a internally rusted mess. I understand the purpose of coolant and it's properties. The point was fact, not myth, that water has better heat transfer than ethylene glycol.
                                                  Bobby

[J. Gomez]

Joshua,

Just finished rebuilding my transmission and I have successfully road tested it.  However, when I go up a prolonged hill (Cajon Pass - a fairly steep grade in Southern California) the engine will begin to run very hot (up to the 3/4 mark).  The engine was rebuilt and has about 750 miles on it.  All of the hoses were changed and the radiator was rodded out.  The heater core was also replaced as well as a new water pump installed.  All new clamps and gaskets.  New thermostat (160 as per the shop manual).  Factory 7 blade fan, fan shroud, and rubber "cover" at the top of the radiator support bar.

The entire time I was on flat ground, I had the factory air conditioning running and I was doing around 70mph.  As soon as I hit the hill, the engine began to go past the 1/2 way mark, I first turned off the air conditioning.  When the temperature kept climbing, I slowed down to 55-60mph.  This helped a great deal and then temperature slowly dropped to the 1/2 way mark.

I do not need to tell you that Cajon pass is a killer for old cars especially about ¼ to ½ way up the hill on either direction during the summer time.

From what I recall way back they had signs at several intervals for drivers to “turn off the A/C to prevent overheating”.

Even with modern cars V6, V8, VXX you will be up and down shifting with normal traffic and speeds. (Now if you get stuck with traffic heading to Sin City or coming back then that will be a different story.   )

As folks had mention above vacuum as the possible issue, well they are “right on”!

When you are going uphill you may going from ½ to full throttle and in between to keep the 70mph speed, these changes will affect the vacuum.

As vacuum starts to drop and goes below the distributor vacuum advance breaking point it will be retarding the spark timing. Once you drop down to 55-60mph the vacuum increases and spark timing will be advancing back to normal. Granted the centrifugal weights will try to keep the spark timing advance but at that high rpm and with a full throttle it will be mood point.

If I recall    there was a modification offer for the old mechanical distributor’s weights and springs for cars driving in steep hill areas. 

I personally thing your engine is functioning normal under normal driving conditions, as you mention when you drop back to 55-60mph everything goes back to normal. 

Just stay away from Cajon pass or Tejon pass during summer time. 

Just my 1/2/ cent.