Over heating

[73Barracuda]

So, I’m starting my cuda project and want to make it a reliable street car first. The jacket water has been rusty since I bought it and from what I can tell the car sat for years before I bought it. But it runs!

On multiple occasions, after draining, flushing and putting new coolant in, the car has over heated. I just replaced the hoses, thermostat, radiator and water pump to try and find a problem. I found rust deposits, but the thermostat looked like it worked, Water pump looked solid, and the hoses were without holes or cracks.

The water temp still climbs. Could the jackets be so rusted that they are clogged? I put a hose in the top and when flushing, water looked like it was running straight through?

Trying to decide on if the 318 is rebuildable or just replace it.

73barracuda....

 

[fasjac]

Well, kinda need some more info. If it’s running ok and just heating up? yea, it’s rebuildable. But, when you say the the water runs straight through. As in leaking somewhere or fast flow past the radiator fill cap? If so , thermostat could be stuck open. As in the water/ coolant flowing too fast fast to cool. You running a fan shroud? Electric fans? Are the hoses possibly collapsing? It actually sound like the stat is open. Need some more details about your set up. You can go down a rabbit hole real quick on heating up issues. Tell us more about the motor.

 

[57fury440]

Are you saying it is running hot based on the temp gauge or is it boiling over?

 

[Cuda Hunter]

If it's the original numbers matching 318 I'm sure it can be rebuilt. Don't get rid of the original motor.
More info about the issue please.

 

[CCKen]

So, I’m starting my cuda project and want to make it a reliable street car first. The jacket water has been rusty since I bought it and from what I can tell the car sat for years before I bought it. But it runs!

On multiple occasions, after draining, flushing and putting new coolant in, the car has over heated. I just replaced the hoses, thermostat, radiator and water pump to try and find a problem. I found rust deposits, but the thermostat looked like it worked, Water pump looked solid, and the hoses were without holes or cracks.

The water temp still climbs. Could the jackets be so rusted that they are clogged? I put a hose in the top and when flushing, water looked like it was running straight through?

Trying to decide on if the 318 is rebuildable or just replace it.

73barracuda....

Have you checked to see if the heater core is blocked. Sometimes that is an issue.

 

[73Barracuda]

Water runs through as in, without being attached to the radiator, water is put in the top and appears to flow through the block passageways, unobstructed.

The rusty water and my lack of knowledge about how long it sat is what worries me.

No fan clutch. I have a thermostat on the radiator cap and it shows hot as well. If ran long enough it will overheat at any speed.

With the quickness the fluid would flash off when driving, I was thinking there could be a break in the line somewhere allowing air in, but I can’t find an opening anywhere.

I know this is a redundant theme and there are many threads, but appreciate your guys input.

 

[fasjac]

Does the oil look good and clean? Not milky..
And you can pressurize the cooling system at the radiator and see if it will hold the pressure on the guage.
You may want to consider a radiator if it been sitting for many years. If it’s all original, you can get another core for the radiator. Heater core can make issues as well. You can flush the heater core at the firewall.
New thermostat and 60/40 ratio of coolant. If you had access to a multi laser thermometer, you could test the temp of the radiator at operating temp.
A manual guage would give you a true reading of “the creeping up” issue.
Just some thoughts.

 

[fasjac]

Let it run/idle and make sure all the air burps out. May take a little while!
And what temp does the cap show?

 

[moparleo]

When you say that you flushed the radiator, did you just run water through it ? Have you used the proper flushing chemicals ? Water won't get anything out but what happens to be loose. It will not break down the rust. That is what the flush chemicals do, breakdown and neutralize rust. The engine has to cast off the heat it develops and can't do that if the water jackets are coated in rust. You never say how hot "overheating" is. What temp and at what speeds ?
The system must hold pressure, have the cap checked as well. At least 16 lbs. If not it will never cool properly. The higher the pressure in the system, the higher the boiling point will be. 200° is not overheating. Temp at idle. Temp at 45 mph. Temp at 60 mph. More info will help a lot.

 

[tonysrt]

You don't say what thermostat rated is in, but you may have a 195* thermostat and your in the ballpark.

 

[Chryco Psycho]

first when does it over heat ? Is it just sitting in traffic idling or running on the highway , the problems are very different , idling is generally lack of efficient airflow through the rad or transfer of heat from the rad so clutch fan & shroud can make a huge difference , on the highway you have lots of air flow so it more related to coolant flow , lower rad hose collapsing , or often timing is not advanced enough .
Years ago a friend went to Carlisle with the intent to buy a better rad & a clutch fan for his Chall , I advanced the timing properly & we sat in traffic going to the fairgrounds & it never got above the thermostat temp so it was all to do with tuning it . I would set the timing at idle to 14-18* with total advance to 36-38* & discard the vacuum advance or dial it back with an allen wrench inside the vacuum pot .