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Trying to solve engine not cooling down

Started by blown motor, January 20, 2023, 12:46:24 PM

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blown motor

I've posted about this before but gave up trying to find the thread. My Charger has a 440 with A/C. If I start getting on it the engine temp goes up and won't come back down (A/C turned off). I can't recall offhand if the A/C is Vintage Air or Classic Air but the A/C rad almost fully covers the engine rad. I'm wondering if this is blocking too much airflow so, to test this, I'd like to pull the A/C rad. Can I just pull the rad, tape up the hose ends and then reinstall and recharge the system? Is there something more involved or will doing this create other issues?
Who has more fun than people!
68 Charger R/T    74 Challenger Rallye 
12 Challenger RT Classic    15 Challenger SXT
79 Macho Power Wagon clone    17 Ram Rebel

Rich G.

You should replace the receiver dryer if you can't completely seal the ends , and vacuum the system down before recharging it.

Dakota

As stated above, you have to open the system to remove the a/c condenser ("radiator"). I can't speak for Canada, but in the U.S. venting refrigerant directly to the atmosphere is a federal crime*.  Most repair shops here can suck out the refrigerant for about $100-120.   I agree that you should change the receiver/drier once things are opened.

*R-12 refrigerant trashes the ozone layer.  134a doesn't hurt the ozone layer but has a global warming potential 1400 times that of carbon dioxide. 

I bought a vacuum pump from Harbor Freight for leak checking and drying out my a/c system, and recharge things myself, or you can pay a shop to do this for you. 


Dakota


As stated above, you have to open the system to remove the a/c condenser ("radiator") Can't speak for Canada, but in the U.S. venting refrigerant directly to the atmosphere is a federal crime.  Most repair shops here can suck out the refrigerant for about $100-120.   I agree that you should change the receiver/drier once things are opened.   

I bought a vacuum pump from Harbor Freight for leak checking and drying out the a/c system, and recharge things myself, or you can pay a shop tondi this for you. 

dodj

It's pretty easy to see if the A/C rad is blocking airflow. I'd be more inclined to look at t-stat, water pump, verify the engine is actually hot etc. Unless that was all covered already in the other thread?
"There is nothing your government can give you that it hasn't already taken from you in the first place" -Winston Churchill

blown motor

Quote from: dodj on January 20, 2023, 05:50:18 PM
It's pretty easy to see if the A/C rad is blocking airflow. I'd be more inclined to look at t-stat, water pump, verify the engine is actually hot etc. Unless that was all covered already in the other thread?

Engine is hot, verified by multiple shots with temperature gun. Thermostat works, verified by temperature gun shots on each side of thermostat. Water pump turns and belt is tight so can't see why it wouldn't be pumping. The cooling system will maintain a temperature but if I get horsing around and it goes up to 200 or 210 it won't come back down to the 180s.
@dodj  How do you suggest I see if A/C rad is blocking airflow?
Who has more fun than people!
68 Charger R/T    74 Challenger Rallye 
12 Challenger RT Classic    15 Challenger SXT
79 Macho Power Wagon clone    17 Ram Rebel

Filthy Filbert

210 isn't hot.  I wouldn't worry until you're north of 230.

I bet it does eventually come back down but you're just not giving it enough time. 


blown motor

15 minutes of easy driving should be lots of time. If my small block gets warmer than normal operating temp it will come back down in a few minutes. With the big block and easy driving it's about 180. Play with it 190, 200. Play some more 210, 220. It keeps going up but doesn't come down. Now I can't play anymore.  :Thud:
Who has more fun than people!
68 Charger R/T    74 Challenger Rallye 
12 Challenger RT Classic    15 Challenger SXT
79 Macho Power Wagon clone    17 Ram Rebel

BFM_Cuda

Do you have a radiator shroud and have you checked the fan clutch?

Dmod1974

Those symptoms do point to a cooling capacity issue with the radiator.....  But, I would rule out the fan clutch and shroud first.  Also, just because the water pump pulley is spinning doesn't mean the impeller on the other end isn't spinning on the shaft, worn/damaged, or the water pump housing cavitated.  What radiator are you running?  Stock, cheapo aluminum, tube size/number?  What ambient temps is this occurring?

Most A/C condensers do take up all of the front cooling package space with no issue.  Is it a stock style, or an aftermarket kind?  The aftermarket kinds flow air pretty freely, so I doubt that is the issue.  If you really want to remove it, you could always draw down an empty refrigerant tank with a vacuum pump and recover the refrigerant yourself, avoiding venting it to atmosphere or having to waste time with a shop.  That's how I do it when I have to discharge an A/C system at home.

Filthy Filbert

I think we can rule out fan/shroud/fan clutch issues if he goes from spirited driving to straight and level cruising as long as he's above 40 mph.

But I agree that water flow would be a concern. 


MoparLeo

One major fact that we didn't get. Is this a stock built 440 or is there more to this story ? And why do you think 200-220° is hot ?
What exactly does " when I start getting on it " , or "get horsing around " mean ?
Do you have a coolant recovery system installed on this cooling system or just overflow dump ?
How many lbs is you radiator cap rated at ? Have you had the radiator cap tested ?
Done a cooling system pressure check ?
What type and  mix of coolant are you using ?
Is this an automatic car with a high stall convertor or a manual transmission ?
As you can see there are many variables to your question.
The more detailed info we get, the more educated possible answers we can give.
No different than going to the Dr. with an issue. More info, better diagnosis.
moparleo@hotmail.com  For professionally rebuilt door hinges...

dodj

Quote from: blown motor on January 20, 2023, 08:15:44 PM
@dodj[/url]  How do you suggest I see if A/C rad is blocking airflow?
I just think it's easy to look through the ac rad. If you can see through it...it's not blocking.
Have you taken any steps to deal with this in the previous thread? Tested the clutch etc?

"There is nothing your government can give you that it hasn't already taken from you in the first place" -Winston Churchill

blown motor

Three core aluminum rad with shroud. Edelbrock top end kit estimated to make about 475 hp. Replaced fan clutch with new one, no difference.
@MoparLeo  Getting on it and horsing around means anything that will put back in the seat. Thought you could have figured that out.
Who has more fun than people!
68 Charger R/T    74 Challenger Rallye 
12 Challenger RT Classic    15 Challenger SXT
79 Macho Power Wagon clone    17 Ram Rebel

BFM_Cuda

Quote from: blown motor on January 21, 2023, 08:38:30 PM
Three core aluminum rad with shroud. Edelbrock top end kit estimated to make about 475 hp. Replaced fan clutch with new one, no difference.

Does your fan match up well with your shroud? In other words, does the fan sit inside the shroud properly front to back? How much gap is there between the fan blades and the shroud?

I went through this same issue on my 70 Coronet. I bought a larger diameter fan from Summit to get the blade/shroud spacing down to a minimum. It made a noticeable improvement on the amount of air being pulled though the radiator over the smaller fan I started with.

Just trying to think of things to look at that haven't been mentioned yet.  :alan2cents: