318 Running Really Hot

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JLanzino

JLanzino

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The day after I get my brakes fixed, the coolant temp sensor went bad, replaced it and now the gauge is reading really hot, and can feel the heat, I did a thermostat, coolant flush and still running hot.

Bad Rad or Water Pump?? its on the 1960 Dart 318
 
did it run hot before the sender failed ? I asked because this isn't making sense to me. maybe you got faulty sender. If you have a ohms meter... 80 ohms is no needle movement 32 to 34 ohms is 180 to 190 degrees and where most thermostats begin to operate 10 ohms is 250 degrees.
 
Or beg or borrow an infra-red gun thermometer. In other words make SURE it's actually running hot

Is it puking coolant out the overflow?

An engine "properly" running to normal temp with a 190---195 stat on a warm --to -- hot day might SEEM hot
 
Not just any sending unit will work with any gauge. Most are calibrated to the gauge.

Do you have a mismatch perhaps??
 
You've given us so many clues to go on, I just don't know where to begin.
 
RedFish said:
did it run hot before the sender failed ? I asked because this isn't making sense to me. maybe you got faulty sender. If you have a ohms meter... 80 ohms is no needle movement 32 to 34 ohms is 180 to 190 degrees and where most thermostats begin to operate 10 ohms is 250 degrees.
Click to expand...

It was showing 1/4 Gauge movement, It feels the same to me.


67Dart273 said:
Or beg or borrow an infra-red gun thermometer. In other words make SURE it's actually running hot

Is it puking coolant out the overflow?

An engine "properly" running to normal temp with a 190---195 stat on a warm --to -- hot day might SEEM hot
Click to expand...

It is puking coolant out the overflow

Where the needle was before: C--'--------H

Where it is now: C------'----H

When I shut it off to check it C--------'--H
 
Did you recheck the coolant again after you filled it?
Might have been low, because it doesn't make sense that it runs hotter after a sensor replacement.
 
Coolant is full after puking, I mixed it 65/35 for a strong blend, but it seems like its hot, Thats whys puzzling me
 
RedFish said:
did it run hot before the sender failed ? I asked because this isn't making sense to me. maybe you got faulty sender. If you have a ohms meter... 80 ohms is no needle movement 32 to 34 ohms is 180 to 190 degrees and where most thermostats begin to operate 10 ohms is 250 degrees.
Click to expand...

My gauge is Reading 75 Ohms when hot (Hot being C--------'--H) , 71.5 after sitting for 45 Min Its Now Reading C-----'-----H

The thermostat I put in starts at 160F to open its a early one
 
Go ahead and yell at me.....but the thermostat is in facing the correct way?
 
JLanzino said:
My gauge is Reading 75 Ohms when hot (Hot being C--------'--H) , 71.5 after sitting for 45 Min Its Now Reading C-----'-----H

The thermostat I put in starts at 160F to open its a early one
Click to expand...


I was offering values at the factory sender you could compare to thermometer.
I don't know what gauge you have or understand where you are checking.
 
Suddenly just started?

Bad thermostat

bad water pump

Junk suddenly worked up into core (see if bottom hose sucks shut with several seconds of prolonged "high cruise" RPM

gases into coolant, IE blown head gasket, etc
 
Ok, I ended up draining 4 litres out of the rad and put back a 65/35 water mix because I put too much contracted coolant here's where the gauge is

Is this ok where it's at??
 

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Well you need to figure out what the temperature actually IS. A factory gauge won't tell you that. Did it stop puking out the overflow? Does your guts tell you it cooled down?

What was the previous ratio of coolant? Frankly, I doubt you have fixed anything.

OVERfilling a rad will not cause overheating, but it WILL cause puking out the overflow until things get normalized.

Last, what is the ambient temperature there? Humidity? "Hot and dry" = poor cooling
 
My 67 Barracuda new from the factory would belch some coolant after climbing the hill my future wife lived on. It always ran about 2/3's up the scale on the gauge. It now runs about 1/3 up the scale (new motor and sender) but measures 185 with the thermal gun. Go to harbor freight and get one, they work great!!
 
Ill have to get a better gauge setup, it still likes to go to the hot side, for what ever the reason it's not staying cool, a friend of mine is coming up tomorrow he was a licensed mechanic ill get him to look at it and see what we can do to get it fixed! Thanks for the help guys!!
 
Well after the diagnosis, the rad is internally breaking down. We ende up draining the system and flushing, chunks of rust particles came out of the rad.

I will be sending out the rad this week for the rebuild unless you guys know of a better rad to install in the old rads place?

Ill be doing a water pump aswell while I'm in there
 
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