440 Overheating 230 degrees

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standup303 said:
How do I verify coolant is circulating. Pop the cap and let the car get to temp and see if it starts moving
Click to expand...
You have a second cap in the top hose iirc.

Take the cap off

If you have no restrictions the coolant will stay below the level of the cap while ideling. Once the thermostat opens you will see flow.

To reduce a potential mess get a piece of rad hose that's big enough to go around the cap opening and is a few inches long to extend the hight a bit.

Now if coolant starts flowing out of the cap hole on the hose you might have a very restrictive rad.



Some questions...

No particular order.

  1. How much coolant did you put into the engine?
  2. Did you test the new thermostat
  3. Is the thermostat installed correctly
  4. When ideling is the fan coming on
  5. Is the pump housing designed for the inlet to be on the lower passenger side. I'm assuming you have a cross flow rad.
Reasons for some questions

  1. You could have a big trapped air pocket. It happened on a 318 I had. I filled the rad till coolant came out. Put the cap on and went for a test drive. The temp gauge rapidly got to the oh **** range. I headed home and shut it off. I could hear boiling on the engine. After it cooled off I was able to add about 3/4 gallon of coolant.
  2. Should always test before putting it on. Boiling water here in CO is more than hot enough for a 180 or even a 190 stat to open
  3. The bulb of the stat should be facing the block, can the stat open on the pump housing and the t stat cover? I recall an engine ( Ford?) that required a specific stat or it could not open. Take your previous stat and force it open with a wedge of some kind and set it in the housing opening, does it sit flat in the housing
  4. I think you answered that already is the airflow the correct direction
  5. If you have a cross flow rad and the inlet and outlet are on the same side the rad has to be internally baffled to force the coolant to snake through the rad. If the internal baffle is missing the flow will go from inlet to outlet without going through the core
 
Last edited:
Dana67Dart said:
You have a second cap in the top hose iirc.

Take the cap off

If you have no restrictions the coolant will stay below the level of the cap while ideling. Once the thermostat opens you will see flow.

To reduce a potential mess get a piece of rad hose that's big enough to go around the cap opening and is a few inches long to extend the hight a bit.

Now if coolant starts flowing out of the cap hole on the hose you might have a very restrictive rad.



Some questions...

No particular order.

  1. How much coolant did you put into the engine?
  2. Did you test the new thermostat
  3. Is the thermostat installed correctly
  4. When ideling is the fan coming on
  5. Is the pump housing designed for the inlet to be on the lower passenger side. I'm assuming you have a cross flow rad.
Reasons for some questions

  1. You could have a big trapped air pocket. It happened on a 318 I had. I filled the rad till coolant came out. Put the cap on and went for a test drive. The temp gauge rapidly got to the oh **** range. I headed home and shut it off. I could hear boiling on the engine. After it cooled off I was able to add about 3/4 gallon of coolant.
  2. Should always test before putting it on. Boiling water here in CO is more than hot enough for a 180 or even a 190 stat to open
  3. The bulb of the stat should be facing the block, can the stat open on the pump housing and the t stat cover? I recall an engine ( Ford?) that required a specific stat or it could not open. Take your previous stat and force it open with a wedge of some kind and set it in the housing opening, does it sit flat in the housing
  4. I think you answered that already is the airflow the correct direction
  5. If you have a cross flow rad and the inlet and outlet are on the same side the rad has to be internally baffled to force the coolant to snake through the rad. If the internal baffle is missing the flow will go from inlet to outlet without going through the core
Click to expand...
1. I filled the engine, let it warm up with rad cap off and then added coolant to the top of the rad after it cycled for a few minutes.
2. Yes I did test this EMP stat and it opened fine.
3. The bulb is facing the block.
4. Yes fan is coming on at idle.
5. I believe the pump housing is designed for this setup. It is a passenger side specific housing.

I see what you’re saying with the inlet hose cap. I’ll give that a shot when I’m home tomorrow. I’ll grab a video of how much it’s flowing.

This radiator came with the car and worked OK with the 360LA but when it was above 85 outside the temps would get high on that setup as well.

Been researching radiators. So much info. Probably going with Cold Case if they get back to me on some fitment questions. I’m already wired up for electric fans but tough to find a radiator/electric fan setup to clear my water pump pulley. It would be so much easier to get a radiator in there with a clutch/fan setup.
 
To verify the radiator's effectiveness, you remove it and take it to a professional radiator shop and let them test it. They will flow test it and see if it has a restriction. It certainly seems from your IR gun test that's what the problem is.
 
RustyRatRod said:
To verify the radiator's effectiveness, you remove it and take it to a professional radiator shop and let them test it. They will flow test it and see if it has a restriction. It certainly seems from your IR gun test that's what the problem
Click to expand...
26” Cold case being delivered today. I’ll find out the expensive way if it’s the radiator or not!
 
Last edited:

new radiator is in, went with a Derale 16” flex fan since that’s all that I have room for. Car was right at 197 going 60mph, then about 205 at 40 mph. Then got back onto the highway doing 60 and temp kept climbing. Gauge was maxing out at 260. Second I pulled in the garage I put the temp gun on random parts of the radiator, near gauge sensor, metal near inlet and outlet of rad, nothing read above 200. So may be a gauge issue. Probably going to take it to a shop because I’m really sick and tired of dealing with this car at this point.
 
Does your stock temp gauge work?

If so put it back to functional and see what it does.

On a side note.

If the sender is designed for a specific gauge and it's not the gauge you have, that could skew the gauge readings.

For instance of the gauge needs 72 to 10 like the stock sender, but the gauge needs 50 to 5 (just a number i made up) the gauge will read significantly higher then the actual real temp.

Easy to check.

When the temp gauge reads 220 or there abouts, remove the temp sender wire and measure the resistance between the tip of the dented to a good ground. if you get around 10 to 15 that would indicate a correct

You can check the OEM sender if it is still installed on the car.

Resistance between the sender and ground sender wire removed from sender.

The resistance values on the left relate to the temp on the bottom. If you measure
20 ohms the engine coolant temp should be around 225 deg


Screenshot_20250720-133238.png
 
Dana67Dart said:
Does your stock temp gauge work?

If so put it back to functional and see what it does.

On a side note.

If the sender is designed for a specific gauge and it's not the gauge you have, that could skew the gauge readings.

For instance of the gauge needs 72 to 10 like the stock sender, but the gauge needs 50 to 5 (just a number i made up) the gauge will read significantly higher then the actual real temp.

Easy to check.

When the temp gauge reads 220 or there abouts, remove the temp sender wire and measure the resistance between the tip of the dented to a good ground. if you get around 10 to 15 that would indicate a correct

You can check the OEM sender if it is still installed on the car.

Resistance between the sender and ground sender wire removed from sender.

The resistance values on the left relate to the temp on the bottom. If you measure
20 ohms the engine coolant temp should be around 225 deg


View attachment 1716432371
Click to expand...
It’s a mechanical gauge with the capillary tube and liquid.
 
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