How hot is too hot ?

[Los_Control]

I think my truck was parked because it was over heating. I found one T-stat housing stud broken. Which means they worked on it and quit.

I fixed the stud and left out the original old school T-stat that was in it. It quickly warmed right up and went to 200+ degrees like yours.

 

Through the advice of this forum, I removed the water pump and I rodded out the water distribution tube. It was plugged solid. I used a piece of flat 1/4"x1" steel.

I drove it into the tube tapping it with a hammer, and had a hole drilled into the back end so Could connect a slide hammer and pull it back out.

Back and forth just tapping it with the hammer to break up the build up inside of it. It was so plugged, I could not even run a stiff wire through it.

 

Then I pulled the welch plugs, and used wire to reach in and pull out the casting sand that was left in it ... amazed how much was pulled out.

Then used a garden hose in the distribution tube and flushed it all out good.

Put it back together,  Then filled it with vinegar, let it run and warm up through a few heat cycles and after a few days drained it and put in fresh vinegar and repeat. Let it warm up and soak.

Still not on the road driving it, but can let it idle for a hour and it will slowly creep up to 190. fast idle and drops right down to 170. Pretty sure with a T-stat installed it will maintain a steady 180.

 

The distribution tube, which most would suggest to replace, and the left over casting sand in the blocks, is a common mopar flathead 6 issue.

[40desoto]

19 minutes ago, Los_Control said:

I think my truck was parked because it was over heating. I found one T-stat housing stud broken. Which means they worked on it and quit.

I fixed the stud and left out the original old school T-stat that was in it. It quickly warmed right up and went to 200+ degrees like yours.

 

Through the advice of this forum, I removed the water pump and I rodded out the water distribution tube. It was plugged solid. I used a piece of flat 1/4"x1" steel.

I drove it into the tube tapping it with a hammer, and had a hole drilled into the back end so Could connect a slide hammer and pull it back out.

Back and forth just tapping it with the hammer to break up the build up inside of it. It was so plugged, I could not even run a stiff wire through it.

 

Then I pulled the welch plugs, and used wire to reach in and pull out the casting sand that was left in it ... amazed how much was pulled out.

Then used a garden hose in the distribution tube and flushed it all out good.

Put it back together,  Then filled it with vinegar, let it run and warm up through a few heat cycles and after a few days drained it and put in fresh vinegar and repeat. Let it warm up and soak.

Still not on the road driving it, but can let it idle for a hour and it will slowly creep up to 190. fast idle and drops right down to 170. Pretty sure with a T-stat installed it will maintain a steady 180.

 

The distribution tube, which most would suggest to replace, and the left over casting sand in the blocks, is a common mopar flathead 6 issue.

Thank you LosControl. My engine is a fresh rebuilt and a new water distribution tube installed.  Ive had had a similar issue on an older motor I had overheating issues as well.  

[Sam Buchanan]

Simple physics; at sea level water boils @ 212*F, it doesn't expand prior to boiling. "Expansion" is due to steam bubbles trapped in the water resulting from localized temps above 212*. Water at sea level pressure cannot be heated higher than 212* regardless of how much heat you throw at it, it just changes phase (steam). That is why pressurized systems will run at higher temps, the higher pressure raises the boiling point.

 

If water is being ejected at an indicated 175*, then either the gauge is defective or there are areas within the system that have exceeded 212* which is creating steam that is pushing water out the vent.

Edited October 6, 2019 by Sam Buchanan

[40desoto]

I used two different infrared thermometers (to check accuracy)  and both read 175-180 at the rear of the head when guage read 178ish  

at that point, the  thermostat housing read 165 and the top of the radiator read 148.

 

Something just doesn’t seam right.  I will continue to troubleshoot.

 

not sure if its relevant but I did notice even at the first time filling with water after the. Rebuilt when i drained the wAter looked very dirty.  Brownish/red rust color like.

how detailed does a machine shop go in flushing out the water passages when cleaning an engine block before machining? 

 

 

[Los_Control]

Are you sure it is not exhaust blowing the coolant out of the radiator?

There is a kit you can buy, or think autozone will loan, but it detects exhaust gasses in the coolant.

Only way the gasses could be present is a blown head gasket or a crack somewhere.

 

The test is a tube that replaces the radiator cap, there is a dye you put in the tube and it will change colours if exhaust gas is present .... pretty simple test, kit is about $50 last time I bought one ... and handy to have around.

 

When I called autozone to ask if they had a kit, they offered to loan me one ...

Edited October 6, 2019 by Los_Control

[40desoto]

Thank you Los Control.  Here's my update.

I flushed out the water from the radiator and block. filled with water and coolant.  Filled radiator all the way to the top.

ran the car and about 13 minutes in the car guage spiked to 210.  At about 180 I noticed a bit of coolant trickling out of the overflow tube on radiator.

when it got to 210 it was flowing out pretty fast.    When it hot to 190 I turned on the electric fan and the temp kept rising and did not stop at 210, when it got to 215 I just the motor off. When I shut the motor off the coolant continued to gush out pretty consistently for another minute or so.

 

Keep in mind that I used a non-pressurized cap.

 

Until I get the kit to measure any exhaust leaks in the car, Im going to concentrate an another part of the car to get mind off of it for a bit and stay sane.

 

Thanks to everyone for all the advise and insight.

 

 

 

[Sam Buchanan]

Perhaps you need to start the fan when you start the engine? It is much easier to keep an engine cool than recover a hot engine......

Edited October 7, 2019 by Sam Buchanan

[Los_Control]

21 minutes ago, 40desoto said:

Until I get the kit to measure any exhaust leaks in the car, Im going to concentrate an another part of the car to get mind off of it for a bit and stay sane.

Sounds like you have a good plan. This is suppose to be a fun and relaxing hobby 

 

Yesterday I thought later I did not explain it right.

The kit will tell you if you have compression from your engine getting into the coolant system, the compression will blow the coolant out of the radiator.

The exhaust gas is simply a by product from the compression leak. And a sure way to test for the leak.

Your engine will overheat under this condition, mainly because the compression blew all the water out and it is low on coolant.

This does not sound like what you describe above.

 

I am back to thinking you do not have any flow. I am sorry for not reading the whole thread and need to go back and do so.

For example, I do not know why you are running a electric fan.

I just redone the cooling system on my neighbors 1954 shoe box, 5.0/AOD and it is running a electric fan ... they work fine.

 

I am thinking a  T-stat stuck closed, a water pump that is not working .... A radiator that is plugged.

I would trouble shoot this, First thing is pull the bottom hose from Radiator, put water in the top ... is the water coming out the bottom as fast as you are putting it in the top?

1, start it cold with radiator cap off. Do you see water circulating ... as it reaches operating temp, does the top hose get warm as the T-stat opens? Is it circulating?

2, If you do not see water circulating, I would pull out the T-stat and run it without one, see how it reacts .... I need a T-stat in my engine to raise the temp up, does not overheat with it removed.

3, If still running hot, I would remove the water pump, and put a hose in the distribution tube and and check the flow coming out. Is it coming out as fast as it is going in?

Also check the drain plug on the side of the block, if you open it does water flow out? If full of sand it would probably be plugged and not flow.

 

I worked with a guy, the propeller shaft on his water pump broke. The water pump did not leak and gave no indication it was bad, but it did not circulate water ... Just saying I have seen bad water pumps.

 

[greg g]

The water pump impellor is secured to the shaft with a pin. If the pin shears, the pump can spin with out spinning the impellor or turning it too slowly for sufficient flow.  You can check this by removing the heater return thingie from the top of the pump, inserting a screwdriver to block the impelors movement, then trying to turn the pulley. If the pulley moves but the impellor doesn't, you may have found your problem.

[kencombs]

Just a few observations after rereading all of this: (and assuming that the engine is on a stand with a box fan of some sort blowing through the rad)

1.  Running under no load an engine doesn't generate all that much heat so reaching 210 in 10 minutes is indicative of something very wrong.  Low water or air flow would be my first suspects.

 

2.  On the other hand 210 isn't necessarily 'too' hot, just not under those conditions.

3. Water overflow due to cold to hot expansion should be minimal.  Lots of overflow could be hot spots in the head or block, combustion leaks or??  The early discussion of stud leaks makes me sort of suspect the latter.

 

4. The discussion or welch plug failure due to a pressured system is confusing to me.  Welch plugs have been in use in every engine for ever and I've never heard of or seen a pressure related failure.  Lots of rust sure, but these 1 5/8" plugs have just over 2 square inches of surface area.  with a 10PSI cap you would only have 20 lbs total pressure pushing on the plug. You can push that hard with your finger!    I just can't conceive of that pushing a properly installed/expanded plug loose.  The plug is convex before install and concave after.  That changes its diameter a little bit.  but, if driven too far it will begin to shrink again.   My plan is to use a modern heater core and run a 10-12 lb cap on mine when complete.  I'll be adding AC at some point and the higher boiling point will be useful in traffic.

 

5.  If I were working on your setup, I'd probably put a pressure tester on the radiator cap and pump it up to 12-15 lbs.  If it holds for several minutes, then let it set overnight.  Pull the coil wire and crank it over several times.  Then pull the plugs and check for evidence of water.

 

6.  newer or rebuilt pumps often have impellers made of plain steel sheet.  I've encountered more than one that had all the fins corroded away.

 

OK,   I'm through rambling.

 

edit:  well I thought I was through but forgot something.  You stated that the cap opens and releases water into the overflow res.  That is normal, While the water doesn't expand a lot as it heats, the air over the water  in the radiator does, and creates  pressure.  The outflow of air will take some water with it, especially if newly filled and slightly overfull.

 

reedit: one more thing, I have heard of more than one new radiator having a shipping plug in the inlet or outlet.  I mean completely in it, as one inserted and followed by another.  the installer pulled the visible plug and got results similar to what you're experiencing.

 

 

 

Edited October 7, 2019 by kencombs

[Dodgeb4ya]

Have you checked the  top to bottom of the block and radiator with a infrared thermometer continuously as the engine and rad warm up?

The rad should have no cool spots anywhere on it once the engine is up to 200+....if the engine heats quick to 200... the lower 1/2 of the rad is still say 80 degrees, upper half warm to hot... that generally means no coolant circulation.

Once the thermostat immediately opens the whole rad will get hot...upper 1/2 warmer than the lower 1/2

I can tell this easily with my hand. As for how good does a machine shop clean out the block coolant passages.....I don't think ever well enough.

It's possible the new radiator is blocked..

Why don't you pull the hoses off it ......Plug the lower outlet..fill it full... pull the lower outlet plug...you should see a 6" thick high stream of water immediately pour out and empty the rad completely...and fast!

I ran this Mopar six for 45 minutes...just a good old running engine and it runs about 170 degrees in the hot summer heat... stock fan ane a way too small rad.

Edited October 8, 2019 by Dodgeb4ya

[rvannoy1]

Back in the sixties I had a 47 P15 with a 54 - 230 bored 0.060 and it never, ever got hot. It had stock radiator with no pressure cap and all.

Now I have a 48 P15 with a 56 Chrysler 354 Hemi and it runs about 190 - 205 on a hot summer day it has an aluminum radiator, electric fan, 11 psi cap and shroud. But it also has an air conditioner condenser in front of the radiator. I have been considering trying to remove the modified inner fenders completely to see if that might allow more air to get out from the engine compartment.

Did you put the water distribution tube back in the block after your rebuild? That will really mess with the cooling system if you didn't.

 

Ron

[mlozier76]

It may have been addressed already, but flush your system if not done so already.  I literally spent an hour with a hot pressure washer and the freeze/welch plugs out to get mine cleaned.  I elevated it both forward and backward.  I drove it around for a year or so before I pulled the motor to clean because I was so concerned about it overheating.  I have several grades around here that I go up and down everyday when I drive the car, from 2700ft to 750ft elevation, with one at 7% grade. I highly recommend doing this if the car has sat for a while.  Mine hadn't been driven regularly sine 1969.

[40desoto]

On 10/7/2019 at 3:09 PM, kencombs said:

Just a few observations after rereading all of this: (and assuming that the engine is on a stand with a box fan of some sort blowing through the rad)

1.  Running under no load an engine doesn't generate all that much heat so reaching 210 in 10 minutes is indicative of something very wrong.  Low water or air flow would be my first suspects.

 

2.  On the other hand 210 isn't necessarily 'too' hot, just not under those conditions.

3. Water overflow due to cold to hot expansion should be minimal.  Lots of overflow could be hot spots in the head or block, combustion leaks or??  The early discussion of stud leaks makes me sort of suspect the latter.

 

4. The discussion or welch plug failure due to a pressured system is confusing to me.  Welch plugs have been in use in every engine for ever and I've never heard of or seen a pressure related failure.  Lots of rust sure, but these 1 5/8" plugs have just over 2 square inches of surface area.  with a 10PSI cap you would only have 20 lbs total pressure pushing on the plug. You can push that hard with your finger!    I just can't conceive of that pushing a properly installed/expanded plug loose.  The plug is convex before install and concave after.  That changes its diameter a little bit.  but, if driven too far it will begin to shrink again.   My plan is to use a modern heater core and run a 10-12 lb cap on mine when complete.  I'll be adding AC at some point and the higher boiling point will be useful in traffic.

 

5.  If I were working on your setup, I'd probably put a pressure tester on the radiator cap and pump it up to 12-15 lbs.  If it holds for several minutes, then let it set overnight.  Pull the coil wire and crank it over several times.  Then pull the plugs and check for evidence of water.

 

6.  newer or rebuilt pumps often have impellers made of plain steel sheet.  I've encountered more than one that had all the fins corroded away.

 

OK,   I'm through rambling.

 

edit:  well I thought I was through but forgot something.  You stated that the cap opens and releases water into the overflow res.  That is normal, While the water doesn't expand a lot as it heats, the air over the water  in the radiator does, and creates  pressure.  The outflow of air will take some water with it, especially if newly filled and slightly overfull.

 

reedit: one more thing, I have heard of more than one new radiator having a shipping plug in the inlet or outlet.  I mean completely in it, as one inserted and followed by another.  the installer pulled the visible plug and got results similar to what you're experiencing.

 

 

 

Thank you Ken!  Great advise.  I will be renting a pressure tester and doing the pressure test along with checking that the water pump is circulating water.  I have a feeling its not because the water temperature varies drastically around the block and radiator.

 

 

[40desoto]

Update-

About a month ago I started the engine, idle seemed fine but quickly climbed to about 210 with fan running in front of radiator,  The lower rad hose came off of the water pump outlet and sprayed hot water on me and all over the garage.  I was having a hard time reaching into the switch to turn it off the noticed that water was sitting on top of the air cleaners and the motor suddenly shut off.  Im assuming that radiator water got into the carburetors, shut the engine off and decided to let the engine set aside for about a month..

 

This weekend I removed the head, thermostat, and water pump in order to check to make sure the water pump was spinning freely and to make sure that the new water distribution stick was installed. When removing the head I noticed that there was water in some cylinders and water in some of the intake valve chambers.  Since I started removing the head nuts before draining the water, Im assuming that water got into those areas when loosening the head?  It did water get into the intake valves from the carburetors?

 

I tested the 160 degree thermostat, air blew the water out of the chambers, resealed and tightened the studs into the block and put a new head gasket on.  Torqued in the proper sequence

40, 45, 50, and 55

When I ranked the engine it started right away but was idling a lil rough, the good think was that it didnt get hot so quickly and when the thermostat opened it slightly cooled the water and when reving it a bit the temperature went down.  The temperature maintained at 190 for about 20 minutes but the idling got rougher.

 

Heres the interesting part- I let the engine cool for a couple of hours, re-torqued the head in sequence back to 55.   When I started the engine after re-torquing it puurred really smooth for about 20 minutes, after 20 minutes the temperature went up to 200 and the engine started idling really really rough again.  I shut it off again and it has not been started again since.

Keep in mind that this is without a fan blowing into the radiator, just the stock fan.

 

Is this normal?  The only think I can think of is that the head is not torqued enough and Im thinking of going to 60 to make sure its sealed.

 

 

 

 

[James_Douglas]

Try this and report.

 

1. Make sure the engine is dead cold overnight.

2. Remove the radiator and the fan and the thermostat.

3. Put the T-Stat housing back empty.

4. Put the radiator hoses back on the engine side.

5. Stick a garden hose into the water pump intake hose.

6. Turn it on and let water flow out onto the driveway.

7. Start the engine..

8. Let it run and keep an eye on the temp.

9. Record the temp every 5 minutes for 30 minutes or until it gets over 200F.

9a. Shut it down and take out all six plugs, line them up and photograph them.

10. Come back here and report the results.

 

If the engine temp gets over about 160F then there is something wrong in the engine. Either the water pump is not doing its job or the water distribution tube was not put in correctly or the block was not cleaned correct or something in the compression chamber/cylinder is blowing into the water jacket. The last possibility is that the thing is running WAY to LEAN and it is getting hot from that. If it is a lean condition then the plugs will show the tale.

 

James.

 

 

[40desoto]

Thanks James, unfortunately in California I cant let water run and drain for 30 minutes.

Maybe Ill adapt a hose to run to my home plumbing drainage.

 

by flushing water through the water pump input as you stated- would it just flush out of the pump without it flowing through the engine?

I will look into giving it a shot and see.

I have a plumbing drainage bladder that Im thinking of using to make sure the water does not spill over.

 

[Sniper]

I just retorqued my head, pretty sure the spec was 70 ft/lbs.

[40desoto]

13 hours ago, Sniper said:

I just retorqued my head, pretty sure the spec was 70 ft/lbs.

Hey Sniper Im using studs. For studs with the finer thread the torque is 55 for bolts its 70.

I am temped to go to 60 or so but I heard it can cause damage

[Dodgeb4ya]

7/16" X 20 fine thread at the top head studs should be torqued to 55 ft lbs.

Regular 7/16" X 14 tpi course threaded head bolts are torqued to 60-70 ft lbs.

[soth122003]

On 1/3/2020 at 1:08 PM, 40desoto said:

About a month ago I started the engine, idle seemed fine but quickly climbed to about 210 with fan running in front of radiator,  The lower rad hose came off of the water pump outlet and sprayed hot water on me and all over the garage. 

I've read this whole thread again. From your first entry you said you have a 3 core aluminum radiator. Do you still have the original radiator for your car? If it is in decent condition you might give it a try. Reason being if you aluminum radiator flow rate is to fast your water won't stay in long enough to cool down properly before going back into the engine. How fast did your radiator drain when the hose came off?  lightning quick or was it steady at about 10-20 seconds for the drain? If the radiator is good then I would say pull the water pump, t stat housing and freeze plugs and flush the living snot out of the engine. If you have no leaks of water to oil or oil to water, you have a flow problem. Either to fast or to slow. 

 

Joe Lee

[Lloyd]

On 1/3/2020 at 1:08 PM, 40desoto said:

Heres the interesting part- I let the engine cool for a couple of hours, re-torqued the head in sequence back to 55.   When I started the engine after re-torquing it puurred really smooth for about 20 minutes, after 20 minutes the temperature went up to 200 and the engine started idling really really rough again.  I shut it off again and it has not been started again since.

Keep in mind that this is without a fan blowing into the radiator, just the stock fan.

 

Ive had blown head gaskets that acted just like that. I know you replaced the gasket but has the head been checked? May be uneven, cracked or even a crack in the block.

Few things to check, color of exhaust smoke will be white, oil may be contaminated with water making it a milky looking color, water on a spark plug, oily mixture on bottom of radiater cap.

Since the engine ran well cold then idled rough at 200 a compression check before and after the engine has warmed up can help as well.

 

[Sniper]

5 hours ago, soth122003 said:

Reason being if you aluminum radiator flow rate is to fast your water won't stay in long enough to cool down properly before going back into the engine.

 

Doesn't work like that at all.  Go read up on thermodynamics and heat transfer.

 

But to sum up, Newton's law of cooling states that the rate of heat loss of a body is directly proportional to the difference in the temperatures between the body and its surroundings.

 

Time is immaterial, faster water flow promotes more turbulence that allows the coolant to be as fully exposed to the heat source (engine) and the heat exchanger (radiator) as is reasonable within the constraints of the system. 

[James_Douglas]

If you have a lawn or a tree or a shrub...just run the output of the water over that area and do the test...

[40desoto]

On 1/5/2020 at 4:15 AM, Lloyd said:

 

Ive had blown head gaskets that acted just like that. I know you replaced the gasket but has the head been checked? May be uneven, cracked or even a crack in the block.

Few things to check, color of exhaust smoke will be white, oil may be contaminated with water making it a milky looking color, water on a spark plug, oily mixture on bottom of radiater cap.

Since the engine ran well cold then idled rough at 200 a compression check before and after the engine has warmed up can help as well.

Hey Loyd one thing that I thought it can be would be an uneven head or deck on the block.  Im praying that its not.  Im going to run it through  couple more heat cycles and retorquing it each time it cools down with hopes that it stabilizes.