My car doesn't like hot weather

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I've got a 67 300 with 440 TNT engine and automatic. The car runs fine with no issues as long as the temperature is below 80 degrees. Once it gets hotter than that it has two issues that make it annoying to drive. The first one's been with me since I've owned the car (12 yrs) and the other for about a year now.

If I sit at a traffic light for a few minutes the temp starts to creep up. It's usually 180 rock solid as long as it's below 80. It creeps up to 200 or so within a minute or two. It does go back down to 180 once I get moving. If I sit in traffic or go from stop light to stop light the temp never goes down but continues to go up. It's annoying because I'd hate to get stuck in a big traffic jam in the summer so I try my best to avoid a lot of traffic. The car has a 180 stat, a 3 row core 26" radiator from Glen Ray, a 6 blade fan from Bouchillon Performance with a fan clutch (aftermarket) and the stock shroud. Any ideas or is this normal behavior?

The new issue is once the car is good and hot on an 80 or above day it will usually take off from a stop or a light normally but occasionally when you step on the gas it will BOG down big time feeling almost like the ignition has stopped. Let off the gas and in a few seconds it's fine again.
 

Welder guy

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My car did the same thing. I removed my fan and replaced it with a electric fan that is thermostatically controlled. All of my issues disappeared. I can sit in a traffic jam for a hour and the car will not over heat now.
 

Xenon

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I've got a 67 300 with 440 TNT engine and automatic.

The car has a 180 stat, a 3 row core 26" radiator from Glen Ray, a 6 blade fan from Bouchillon Performance with a fan clutch (aftermarket) and the stock shroud. Any ideas or is this normal behavior?

The new issue is once the car is good and hot on an 80 or above day it will usually take off from a stop or a light normally but occasionally when you step on the gas it will BOG down big time feeling almost like the ignition has stopped. Let off the gas and in a few seconds it's fine again.

Loose the 180 thermostat and replace with a 190.....
This will allow the coolant to stay in rad longer hence run cooler....

The hesitation is more than likely from accelerator pump..
You can try to adjust it but usually when they get old they need replacing....
 

detmatt

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can you post up some pics of the cooling system, shroud etc..?
 

traintech55

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I've got a 67 300 with 440 TNT engine and automatic. The car runs fine with no issues as long as the temperature is below 80 degrees. Once it gets hotter than that it has two issues that make it annoying to drive. The first one's been with me since I've owned the car (12 yrs) and the other for about a year now.

If I sit at a traffic light for a few minutes the temp starts to creep up. It's usually 180 rock solid as long as it's below 80. It creeps up to 200 or so within a minute or two. It does go back down to 180 once I get moving. If I sit in traffic or go from stop light to stop light the temp never goes down but continues to go up. It's annoying because I'd hate to get stuck in a big traffic jam in the summer so I try my best to avoid a lot of traffic. The car has a 180 stat, a 3 row core 26" radiator from Glen Ray, a 6 blade fan from Bouchillon Performance with a fan clutch (aftermarket) and the stock shroud. Any ideas or is this normal behavior?

The new issue is once the car is good and hot on an 80 or above day it will usually take off from a stop or a light normally but occasionally when you step on the gas it will BOG down big time feeling almost like the ignition has stopped. Let off the gas and in a few seconds it's fine again.
Since your question has two parts, I will answer it the same way,
1. Cooling issue this is a classic sign of trying to do the right thing and mixing parts that do not work well together. What is happening is you are not pulling enough air thru the radiator to remove the heat at idle. Your car looks like it doesn't have A/C, so start with these, CHECK your engine idle speed, if it is to low raise it to about 750 rpm in neutral, or 650 rpm in gear. Every "C" body car I have seen without A/C had a fixed fan blade, (no fan clutch), Your clutch could be bad and slipping, Look to see if it has the temp. activated spring on the front. good way to see if it is slipping is to shine a timing light at the fan, if it is you will see it. You may need to go back to the fixed fan blade. Check the distance from the fan to the radiator, if the fan is to far from it , that could be the problem also. The blade should be 50 /50 with the shroud. MAKE SURE THE FACTORY BAFFLES ARE IN PLACE IN FRONT OF THE RADIATOR. These force the air to be sucked into the radiator and not around it.
2. Your second problem sounds like your engine is getting starved for fuel on acceleration. if it were an accelerator pump it would be all the time and would come back after you backed off the gas pedal. It could be a restriction in the filter in the tank. You can check this by running a separate line and gas can to the fuel pump and see if it goes away.(You will need a second person to do this safely).
Let us know what you find.
 

detmatt

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My first thought on cooling systems is that these cars had no issues when they left the factory so why reinvent the wheel. Some of the top engineers designed these cooling systems custom for each model and for different option within each model so all that really needs to be done is to restore the entire cooling system to as close to factory as possible and you should be good to go.
 

rexus31

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My first thought on cooling systems is that these cars had no issues when they left the factory so why reinvent the wheel. Some of the top engineers designed these cooling systems custom for each model and for different option within each model so all that really needs to be done is to restore the entire cooling system to as close to factory as possible and you should be good to go.

You are correct except for the fact these are 50 year old blocks which may or may not have rust/scale built up in the coolant passages restricting the proper flow of coolant. IMO, that's where it needs to start but the only way to fix that is to have the block sit in a tank over the weekend had have the passages rodded out. Anything else, to your point, is a bandaid as best.
 

detmatt

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When I say restored I mean restored, that includes being completely cleaned and returned to its original capacity.
 

70bigblockdodge

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Does it go over 210 and keep climbing or does it get hot and just hang at 210 and below. If it just warms up and hangs out around 200 in traffic I would say you are doing okay as long as it cools as soon as you start moving. 200 is not overheating as long as your cap is good. A electric pusher fan on the front is not a bad idea but if you get a thermostatic controlled one it will still get warm kick on and then kick off when temp goes down. Direct drive fans are noisey, fuel wasters and for what 20° drop in idle temp.
Another may be the idle time settings, timing and fuel mixture if it is laboring to idle it will cause more heat, I suggest tuning your idle with a vacuum guage higher vacuum it idles easier.
 
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Thanks guys! My car doesn't have A/C and originally had a fixed 4 blade fan with the 26" rad with shroud. The fan and the original rad are lost. Probably foolishly trashed when my car was in a shop for 6 months while the engine was overhauled and other work was done. Sort of a partial restoration.
It's had the cooling issue ever since (10 yrs now). The fan is half way in/out of the shroud and with the clutch in front the blades are probably 1 1/2" from the rad. Car is at my mechanic's now so I'll have to have him check that to be sure but that's what I remember measuring. Not sure what type of clutch it is, whether thermal or torque. It's a Hayden clutch supposedly for my application. I DO have a couple of fan clutches in the garage that are thin with a flat face and a thermal spring in front. Is this the kind I should be using?

Now, not sure about the factory baffles in front of the rad. It does have a seal between attached to the hood that fits between the rad and the rad support. There is also a seal over the bumper support, but its just a small one. Should there be any other seals?? If so can someone post a pic so I have an idea of what I can do.
 

bluefury361

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Thanks guys! My car doesn't have A/C and originally had a fixed 4 blade fan with the 26" rad with shroud.

A non air car with a 4 blade fan and 26" rad doesn't sound right to me. The clutch should be the thermal type and spaced 1/2" to 1" from the radiator.
Have you checked for debris in the cooling fins of the rad, especially in the lower portion. And a collapsed rad hose can cause this issue.
 
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Though it sounds funny because of this post, my car came with the "heavy duty" cooling system! That included a 26" rad, 4 blade fixed fan and a box shroud.
You say the thermal clutch; which one is that? The one with the spring on the front face?? Anyway, no debris in the rad and I have a spring in the hose to keep it from collapsing. Maybe the spring could be blocking the flow??
 

bluefury361

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[QUOTE="67 chrysler300,
You say the thermal clutch; which one is that? The one with the spring on the front face?? QUOTE]


YES.
 

traintech55

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Sorry I did not get back with you yesterday on this. As Bluefury 361 stated, yes the fan clutch with the thermal spring is the one to use, the spring senses heat and make the clutch engage when the temp. gets to high. The spring in your lower radiator hose would have to be and inch thick to restrict the coolant flow so that is not it, it is there to keep the hose from collapsing at high RPM'S. From everything posted after my first post I am certain it is your fan clutch. Use the timing light like I said, and you will see the difference in rotation between the pulley and the fan blade, (funny how the strobe light effect brings this out).
 

70bigblockdodge

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Also if you turn your curb idle up to 1500-1800 or somewhere the fan noise is evident it should cycle it's speed, faster slower, faster, slower you can hear in the noise as the spring does its thing
 

Big_John

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Use the timing light like I said, and you will see the difference in rotation between the pulley and the fan blade, (funny how the strobe light effect brings this out).

I've always been trying to figure out how to check a fan clutch. Thanks for this bit of info!

One of my friends went through some minor over heating issues similar to this. He did some research and tried a few things. He discovered that Hayden made fan clutches that slipped less and drew more air through the radiator. He started using their heavy duty and severe duty clutches and his cars run cooler. As he says, "now the fan will blow your hat off".

Hayden - Fan Clutches and Fan Blades

I replaced mine last year with an aftermarket part. It was a last minute thing I did before Carlisle last year and I didn't have time to order a good one... It was one that was on hand locally. I've noticed, that while it was better than the old one, it doesn't move as much air as I think it should. I'm probably going to replace it this year.
 

bluefury361

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When I started towing Connie with the Admiral I swapped for a 7 blade fixed fan. Usually they are noisier but I didn't notice much difference. They will effect fuel mileage, but in a minimal way. NO issues with overheating, even towing in the mountains with the A/C on.
 

MoPar Maniac

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Another way to test it is with the engine cool spin the fan. It should be diftficult aka not spin freely. When warm it should spin freely.
Also wiggle the blades. If there is play the clutch is shot.
 

Snotty

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Concerning the temps, it sounds normal to me. Apparently you have a degree gauge. If all you had was the idiot light you would not know the temperature; you would probably keep driving without noticing a thing.
 

tbm3fan

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The 200 degrees is normal to me. Both my F100 and Park Lane specify 195 degree thermostats. After I rebuilt the engine in the F100 I early on had heating issues with the engine during break in and afterwards just running at high idle of 1000 rpm. Large radiator, with correct 5 blade fixed fan and shroud. Part of it was the coolant leak into the engine, pegging the temp gauge, from somewhere which took a year to deal with. The other had to do with using the trucks own gauge which lead to an aftermarket gauge. Turned out the aftermarket gauge is not that accurate. In fact it was 19 degrees off the whole time.

So I got smart and stuck a thermometer in the radiator opening and watched the temperatures. At idle of 750 rpm the temp eventually reaches 204 degrees while the aftermarket gauge says 223 degrees and the OEM gauge isn't quite half way. I am comfortable with 204 as the 390 tends to run a little hot. For piece of mind, given all that I went through with that engine, whenever I run it I double check with a thermometer. It is the only way to know exactly where you stand.
 
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