29 chrysler overheating

[mikzjr@aol.com]

I need help with overheating problem took the car out for the first time in two years fresh 100 oct leaded fuel let it run in the driveway for a hour temp was normal, took it for a mile run a couple times temp was normal, so off I went didn't take it over 30 got 5 miles down the road temp over heated, water was gargling out the top of the rad., shut it down waited 10 min. temp was 220 started it up temp dropped down to 160 off I went as I got back to the house temp was over 200. It is a open system no thermostast. Drained the rad I pulled the water pump looks great.  will not over heat in driveway any thoughts.

[Guest]

Probably needs a thermostat or at least a washer to restrict the flow where the stat would be.  At speed the water passes through the rad too fast to be cooled.

[mikzjr@aol.com]

It never had a thermostat and never overheated took it on many long trips at speeds 40 and above.

[Curti]

Is there a water distribution tube running the length of the block behind the water pump? Many times these become plugged.

[hchris]

If its the original engine there would not be a water cooling tube fitted; have you started by simply giving the radiator a good flush out ?

[mikzjr@aol.com]

yes flushed the radiator removed the water jackets flushed them out all holes are open.

Edited September 27, 2015 by mikzjr@aol.com (see edit history)

[frank29u]

Could the fan belt be loose?

[mikzjr@aol.com]

I checked the belt twice.

Edited September 27, 2015 by mikzjr@aol.com (see edit history)

[Matt Harwood]

I don't know if it's related, but maybe the high-octane fuel could be the culprit? Ancient electrical systems don't make much electricity and the energy needed to fire the plugs with 100-octane fuel in there might be too much and it's running incorrectly as a result. I've always had the best results with the cheapest, lowest-octane gas I can find (my 1941 Buick owner's manual says to use 71 octane for best results). The lead is good (but it's not neessarily bad if you don't have it), the lack of ethanol is good, but the high octane rating might be stressing your electrical system and maybe the cooling system.

 

Also, do you trust the gauge? Water gurgling out might just be the system finding its own level, as my 1929 Cadillac pukes water if I fill it to the top. Fill it only to the top of the tubes and it's fine. If it wasn't actually overheating, maybe just the gauge is faulty? It will spike when you park it and the fact that it cooled off quickly when you started means that the radiator is doing something.

Double check temps on the radiator and hoses with an infrared heat gun (not expensive) and maybe double-check your ignition timing. Sounds like you've tackled the hard stuff, this should be something easy-ish.

 

Good luck!

[Matt Harwood]

Oh, while you've got the water pump off, make sure the impeller is firmly attached to the shaft. I had a 1941 Cadillac with a brand new water pump in it that overheated. I chased it for weeks and eventually found that the impeller was spinning on the shaft, so no coolant was moving except by convection. If you've got the pump off, make sure everything is right there.

[mikzjr@aol.com]

I'll check with infra red this week   as for the fuel it over heated with ethanal also.

[Guest Bob Call]

When your 29 was new the octane rating of gasoline was about 60. You are wasting money by buying premium grade. Buy 87 octane "regular unleaded" and maybe add a little diesel, about 10%, to lower the octane. I think you will find the engine runs fine, maybe better than on the high octane.

 

Since you have cleaned and flushed the radiator and engine block, I am thinking you have a circulation problem. Without a thermostat it is common that the coolant circulates through the radiator too fast to transfer the heat to the air. Solution, add a 160 deg. thermostat or otherwise restrict the coolant flow. Another problem is the lower radiator hose. If it is old it may be collapsing and stopping the coolant flow. Run the engine at a fairly high speed and observe the lower hose.  As Matt stated the radiator should be filled to just above the tubes. This gives the coolant room to expand when it gets hot and stops the "puking". Last I would suspect the water pump impeller being loose on the shaft.  If it is a rebuilt pump it may not have the correctly shaped impeller vanes and not moving enough volume of coolant.

Edited September 27, 2015 by Bob Call (see edit history)

[HarryJ]

Check for heavy sediment in the water jackets...possible sediment/clogs in the radiator

[jrbartlett]

We had a '29 Desoto roadster with a similar overheating problem despite freshly boiled out block and clean radiator. We solved it by inserting into the top radiator hose a round block of wood with a half-inch hole drilled into the middle. Yes, the water was circulating too fast. I don't know if a thermostat would have helped -- it might have. This was back in 1964, and I was just a teenager who helped with my father's cars.

[mikzjr@aol.com]

I checked the radiator with a infra red took it out for a short ride to heat it up top of the radiator was 187 the bottom was 177. the head was 187, the inlet at  the pump was 150 how much differential should there be between the top and bottom of the radiator or inlet and outlet.

[Friartuck]

I don't know exact numbers, but a difference of only 10 degrees from top to bottom of the radiator sounds like a small amount. I would expect something like a minimum of 30-40 degrees difference.  In doing the infrared measurements were the edges of the radiator higher than the center. To me that might indicate blockages in the side passages. Have you had the radiator professionally boiled out? Either insufficient air is not getting through the radiator and/or blockages are preventing the heat from dissipating. Also, suggest retorgueing the cylinder head to ensure some minor compression isn't getting into the circulation system. The 177 at the bottom and 150 at the water pump inlet is suspicious, how could it drop that much?

[mikzjr@aol.com]

177 outlet 150 inlet

[hchris]

" how much differential should there be between the top and bottom of the radiator"

 

Ideally you should have about a 30° differential between radiator inlet and outlet, given that we are talking about an older car 20° may be acceptable on the road but marginal in traffic.

[rsb]

I've seen this type of thing before in the older cars. The radiator seems to have good flow but when you feel around the core, the center is hot and the sides are cool. Rust accumulates in the bottom of the core and plugs up the passages. Having it professionally cleaned is hit or miss. The only sure fix is a new radiator core.

[mikzjr@aol.com]

I'm looking into having the radiator recored, mine is honeycomb need help locating the core.

[Friartuck]

A replacement honeycomb is going to be expensive. If boiling out at a commercial shop is not an option, may I suggest cleaning using the Electrolysis method. Use a kids wading pool, large Rubber Maid tub/trash can or similar large container and Arm and Hammer Washing Soda and DC current electricity. Two articles on this topic:

 

http://www.secondchancegarage.com/public/electrolytic-rust-removal.cfm

 

http://www.secondchancegarage.com/public4/gas-tank-cleaning-1.cfm

 

I would try this before spending $3K (or more) for a new radiator. The bottom of the household hot water heater should be fitted with a 3/4 inch hose valve to obtain a stead supply of hot water to flush. Back flush from the bottom. The down side is you may uncover some leaks which can be repaired. Is 2-3 days of your time worth saving this expense? And in full disclosure, I wrote the second article and have personally applied this method for difficult problems.

[hchris]

I'm looking into having the radiator recored, mine is honeycomb need help locating the core.

Ouch, honeycomb is usually prohibitively expensive; have seen some where a blanked section of honeycomb is retained in front of an otherwise conventional replacement core. 

[lozrocks]

I need help with overheating problem took the car out for the first time in two years fresh 100 oct leaded fuel let it run in the driveway for a hour temp was normal, took it for a mile run a couple times temp was normal, so off I went didn't take it over 30 got 5 miles down the road temp over heated, water was gargling out the top of the rad., shut it down waited 10 min. temp was 220 started it up temp dropped down to 160 off I went as I got back to the house temp was over 200. It is a open system no thermostast. Drained the rad I pulled the water pump looks great.  will not over heat in driveway any thoughts.

If the car will sit at idle in the driveway for an hour and not overheat, what happens when you bring the revs up whilst sitting in the driveway? 30mph is not exactly a heavy load on the engine.

[Owen_Dyneto]

First thing I'd do if I could find the specification is to check the gravity flow rate of the radiator. My guess, you'll find it way below spec.

Edited October 2, 2015 by Owen_Dyneto (see edit history)

[WHSEWARD]

Since you have taken the car on trips in the past and have not had the problem, it may be the water pump.  On my 31 Lincoln, a brass shear pin holding the impeller on the shaft sheared without my knowing, the same as Matt mentioned earlier.  It caused a serious overheating problem which had not occurred on a road test prior to my purchase.  If you take the pump apart it's easy to see and was easy to fix on my pump at least.

[mikzjr@aol.com]

took the radiator out today will be sending it out to be tested

[Guest jimstulga]

Hope mikzjr is still watching as I just noticed this topic. Have a '30 Chrysler CJ that had the same honeycomb radiator problem. Honeycomb rad prices were outrageous if you could even find one, so  I had a skilled radiator guy (now deceased) slice the honeycomb into a thin veneer to show at the front and he refashioned a newer style tube and fin radiator behind to do the cooling. Also used the original tank at the top. Can't tell except with close inspection looking in the engine area. Been cooling great for years now. Good luck. 

[mikzjr@aol.com]

Got the results back radiator is pluged getting prices on a new core.

[cahartley]

Get it UNplugged.

Get a few containers of MACS Radiator Flush at a NAPA store and do it yourself.

It contains lye so be careful.......but lye it what it takes to REALLY clean out a core.

If it's that plugged I'd start with at LEAST a 4 × stronger solution and go from there.........unless you have 5-10 grand lying around.

That stuff saved me from having to replace the plugged heater core in my '65 Mustang........NOT a fun job anyone wants to do.

[Spinneyhill]

Do you need to neutralize the caustic sodium hydroxide when you finish?

[cahartley]

Just a good flush with clear water.

Lye, potassium hydroxide, is used every day in the boiler industry for removing oily deposits left over from the manufacturing processes which would be severely detrimental to the metal when under high pressure.

It works faster when heated, but not to boiling, which is why I used a much more concentrated solution when I cleaned out the heater core in my Mustang because it was a cold solution.

You should have seen the crap that came out of there....... 

[mikzjr@aol.com]

I'll look into that thanks for the reply.

[cahartley]

Should you decide to flush it yourself it's very helpful to back flush under some pressure if you can.

Whatever got in there got there flowing in one direction.

Pushing it out the opposite way can help.

I got nowhere with my Stang heater core UNTIL I put air pressure to the core forcing the liquid opposite from its normal flow pattern

Then something let loose and it improved from then on.

If you get a reasonable improvement, and I think you will, I'd install the radiator, use more MACS and run it for a week or longer as heat definitely speeds up the process.

[mikzjr@aol.com]

Thanks for the tip

[Friartuck]

Thought this post on another site provides some numerical data to compare:

 

http://starship.org/Bugsby/Adventures/2009/Radiator-Flow2/Radiator-Flow2.php

 

A 1924 Kissel radiator was measured at 13.5 Gallons Per Minute (GPM).

[ron hausmann]

I couldn't repair my honeycomb 1918 Kissel Sedanette radiator, and didn't want to spend thousands by having a new Kissel configured radiator custom made. Instead, we blanked off the original honeycomb front side which was aesthetically correct and put in a standard radiator behind it to create the right thickness. This new one works better than a honeycomb anyway. Unless your judge is a real stickler, this is a very good solution and you will likely be the only person who is aware of the difference.

Ron Hausmann P.E.

[racertb]

Does this car have a water pump?  I don't know (which is why I'm asking) but my '29 Plymouth (thermo-siphon) had an overheating problem and it was due to lack of water.  Don't get me wrong, the radiator was full, but I went with a 70% water to 30% coolant ratio and that fixed it.  I've read that these old systems need more water to operate properly.  Again, this is on a thermo-siphon system.

[Restorer32]

In the absence of cavitation the speed at which water circulates thru the rad has no effect on cooling. Heat transfer happens at the molecular level. The rad doesn't care how fast water is circulating. Its rate of heat transfer remains the same. If you doubt me ask your local physicist.

[countrytravler]

In the absence of cavitation the speed at which water circulates thru the rad has no effect on cooling. Heat transfer happens at the molecular level. The rad doesn't care how fast water is circulating. Its rate of heat transfer remains the same. If you doubt me ask your local physicist.

I would differ on this comment. I'm not a rocket scientest and know all them fancy words. Just made it through the 9th grade with a d average. We moved 18 times with the last move was 7th grade. Built many race cars and if I ran with no stat, car would overheat with the water circulating too fast. Install stat, problem solved. Had another car that somebody put a 4 row in and it would over heat, installed a factory 2 row, problem solved. Someone said that the rad was too much volume for the water pump to circulate the water.

[C Carl]

In the absence of cavitation the speed at which water circulates thru the rad has no effect on cooling. Heat transfer happens at the molecular level. The rad doesn't care how fast water is circulating. Its rate of heat transfer remains the same. If you doubt me ask your local physicist.

I am not a physicist , but I think I could play one on T.V. for six seconds to sing. Let's see : we have a liquid cooled heat source. The heat will be dissipated through a liquid to air heat exchanger. Given : HEAT TRANSFER RATE IS A FUNCTION OF

TEMPERATURE DIFFERENTIAL. Ambient air temperature is constant. Flow rate of the coolant liquid is variable. Illustrate the problem by imagining two very different flow rates at the extremes. Number one : one gallon per hour. Number two : one hundred gallons per minute. - O.K. , My six seconds are up. Think carefully , and figure out which of these two cases transfers more heat to ambient air through the heat exchanger. You will be graded on your answer. Hint : in the case of the high flow rate , the liquid coolant will be almost isothermic. In the low flow rate , there will be a substantial thermal gradient between the coolant at the heat source , and the coolant in the heat exchanger. - Just an amateur engineer , - Carl

Dave , I have talked to you a few times on the phone , and I know you know what you are talking about. Both you guys know much more about cars than I do , as obviously anyone who works on them all the time knows more than someone who just tinkers occasionally. Man , I would really like to know how a larger radiator does not cool as well as a smaller one. But ya just can't argue with real world experience. Seriously , this is starting to drive me a bit nutser. I gotta go talk to some old hotrodders.Maybe someone here on the forum can explain exactly how this works. I hope so , because now I am having great difficulty trying to wrap my head around all this , since I read your posting. - Confused , Carl

Edited December 4, 2015 by C Carl (see edit history)