So, i finished my timing chain replacement, new water pump; had the radiator to the shop and repaired the lower neck, which was very weak where it attaches, installed it with new hoses, top and bottom, as well as the hoses from the water pump to the thermostat and heater core, etc. The issue is that the radiator won't pressurize, no coolant leaks, i have a 205-degree thermostat installed, temp only goes to about little past 1/3 from cold.; there is heat from the heater, won't roast you out, but i am in Pa. and it's plenty cold here lately. This is nothing new though, i have had the car for 25 years and the hoses always felt like they had very little pressure in them, even in the summer months. I would also say that the rad cap is not new, but i switched it with another used cap, both 16 psi caps, and no difference. I welcome any comments and or suggestions,,,

 

First, I'll be amazed if you really have a "205 deg" thermostat. Stock t-stat in 1966 was 180 degree. Second, how exactly are you determining that the radiator won't pressurize? Have you used a cooling system pressure tester? And I'm sorry but I don't follow what the temp reading has to do with the pressurization.

 

Yes, as i had stated, this has been on-going for a long long time, I know the factory was 180 degrees, i keep upping it over time to get more heat into the cabin. I know it doesn't pressurize because the hoses don't feel like they have pressure in them after, well after, the engine reaches operating temp, I don't' need pressure tester to tell me that. If i run the car for an hour, i can then open the hood and remove the radiator cap without any fear of coolant blowing out; that is how i know it is not pressuring; thanks

 

I appreciate the suggestions/questions Joe provided. I have two of my own.

(1) You don't know what the temperature is in your system because you haven't measured the temperature in your system with any device. Installation of the incorrect 205°F thermostat provides absolutely no indication of the temperature in your coolant system. I suggest you actually measure the temperature as opposed to guessing; and,
(2) You replaced all of those components and you installed a "used" radiator cap? I'm sorry, that makes no logical sense to me. Install a brand new radiator cap, please - they're all of what $8.00 I believe.

Finally, I am not certain of the heater core valve on a 1966 Toronado, but I suggest you ensure you have the correct 1966 Toronado heater core valve & it is installed correctly. There have been others who installed the incorrect heater core valves into their system - ensure yours is correct.

 

I probably missed it somewhere, what was the stated temp reading?

 

When you live 20 miles from the nearest auto parts store (40 mi round trip), you used what you have on hand, i replaced the original rad cap with a cap from my '64 Studebaker Avanti, which had no issues and that system pressurized fine, so i felt being a 16-psi cap, it was worth trying. As far as temperature, the dash gauge reads slightly more than 1/3 off of the cold mark; hope this helps and may stimulate some good suggestions,,,thanks for your reply

 

Forgot to ask, you states that 205°F thermostat provides absolutely no indication of the temperature in your coolant system, isn't that what the temperature needs to reach before opening; isn't that an indication of temperature in the cooling system?,,,thanks

 

It "should" be, yet it provides no indication of what the temperature "is" - so, it's a complete guess.

I can only think of two things which influence what I perceive from your statements to suggest you have no "pressure" in your system, they operate together:

(1) The system must be "closed". If the system is not closed you will not develop pressure, yet this requires a (2) water pump which is capable of circulating water throughout the closed system. If you're not circulating water, the thermostat isn't going to "open" at any temperature. With the car running at nominal normal operating temperature, you should be able to completely fill the radiator to the very top & see water circulating in the radiator. Yes, it's supposed to be filled I think ~1" below the top (optimally), but there should be an overflow/discharge hose on the radiator emanating from the radiator neck. Can you visualize water traversing the radiator core tubing and see it flowing? I'd top off the radiator to the very top, replace the radiator cap, you should get pressure in the system and water should overflow from the discharge/drainage tube. If the system is not pressurizing you have a faulty water pump or an "open" (non-closed) coolant system incapable of pressurizing.

 

Norm, a faulty water pump would result in almost immediate overheating due to no coolant flow through the radiator. I had that happen when the stamped steel impeller fell off the water pump shaft.

 

The water pump is brand new so i would hope that is not the problem; I'm not sure what was meant by an "open" (non-closed) coolant system incapable of pressurizing". If i have no coolant leaks, new water pump, heat/hot coolant circulating into the hear core inside the cabin; I'm at a loss for an explanation!
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I say put a temperature gauge in there. Under dash even. Then you will know.

 

Would an air pocket in the system cause this?

 

I suppose it could but being i have had this same issue long before i did the new timing chain, water pump, etc., and now after changing all these things including new hoses, and had the radiator repaired and pressure tested, i would think i have another problem,,,thanks for your suggestion

 

Yeah, well, I'm at a loss, as well - attempting to think this through. Kenneth brings up a valid point, a failed water pump would overheat the system - I didn't think that through clearly. I'm trying to validate what's going on.

Ok, my simple take is the thermostat is remaining open, it isn't closing (there is no restriction to coolant flow). When the engine begins to warm up, the thermostat should remain closed until it reaches normal operating temperature "range". When it reaches normal operating temperature "range", the thermostat should open either slightly or fully open, depending on engine heat - sitting at idle, WOT, etc. If the heater is blowing cool air the thermostat is not closing to allow the temperature to increase to normal operating temperature range; and, the heater will continue to deliver cool air until the thermostat begins to close - increasing the temperature of the cooling system provides the proper cooling/heating range of the cooling system, thus providing for warm(er) air to the heater. I think you need to lower the thermostat to 180°F and ensure the thermostat is working.

 

I guess it should w/o saying, but I'll say it anyways. Depending on the type of thermostat, and the type of thermostat housing, thermostats need to be installed in the correct orientation. I don't know what that orientation is for your thermostat housing. It should be described with most likely a diagram demonstrating the correct orientation of the thermostat during installation in your CSM.

 

I think Norm may be on the right thought about coolant flow not being restricted by the thermostat, which would result in the coolant not heating up and therefore not pressurizing the system. Back in the 80s I removed the thermostat and the coolant temp stayed around 140 degrees and the system did not pressurize. While I do not know how this may be happening in your engine, the symptoms seem to fit. As suggested, actually measuring the coolant temp will help to diagnose the problem.

 

PS: The question about the air pocket? Air pocket could be at play. Run your motor with the cap off. Let it get warm but not to hot. Let it gurgle. Check the color of the fluid coming up. If good run a little more fluid to bring it up to the top and like said let it overflow for a minute. See what you have. I am not sure that a Toronado has mad pressure in the system. Make sure you have good flow. Put a gauge on there.

 

PS: In a cold State like yours and where I live. Colorado. Bring that thermostat down to the 180 area. Especially in the winter. The degree of the thermostat is where the fluids flow in your engine. That is the lesson. It will get warmer than that temperature but the coolant is flowing. Equals warmer heater...

 

The absolute best, no question there is no air, method to burp all the air from the cooling system is to raise the front of the car. Make the radiator fill the highest point of the cooling system. Elevate the side of the car with the radiator cap a couple feet overnight with the radiator cap off. If there is any air in the system, gravity will naturally work it out.

Cooling system pressure testers are cheap at harbor freight, it would be a worthwhile investment. If you can pressurize the system with the tool, and it holds pressure, safe to say you have no leaks.

Next time your in town, get a radiator cap.

I’m not familiar with the Tempmatic climate control system on the Toronado/big cars, but if there is a noticeable diff in temp between the heater hoses and the rest of the cooling system, the heater core is most likely restricted. Either by debris in the core, or by the heater control valve.

 

As stated above, I would pressure test the system to insure there are no leaks. I would also place a piece of cardboard in front of the radiator and see if the temp rises and therefore builds pressure.