Alright, why is this thing overheating?

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LXguy

LXguy

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Hey All:

Having an overheating problem in my 71 Dart. At idle. When its cold out. Here's the combination.

5.9 Magnum with Iron Ram heads. (MR Gasket LA style head gasket).
RPM Air Gap, 670 street avenger
Hooker comps
new milodon water pump
stock clutch fan with shroud
new radiator (stock one overheated too, was an AC car, so both are the bigger ones)
180* thermostat (works on the kitchen stove)
new coolant/water 50/50 mix

That's all I can think of. Any help is appreciated.

Steve
 
Well two things come to mind.At idel not much air passing through the rad, and slow flow through the engine.Install an black night electric cooling fan,and if not install a water pump for an ac car.Always work on my BB cars mostly chevy tho lol.
 
When is it over heating? At idle or on the highway? Tuning can also cause a car to run hot…….. Timing or Air Fuel Ratio.

Make sure all your tuning stuff is correct before playing with the cooling system.

We have had several of these over heating threads and they can be a pain in the *** to figure out sometimes.
 
You say it's overheating but don't say how hot it is getting.
What kind of temperature gauge do you have?
 
Correct me if I'm wrong but, don't the mag belt drive turn opposite of LA engs

If so, a mix of components could be your problem..............But if the fan was pushing air out the radiator........It would only over heat while driving. Still worth checking it out.
 
Its overheating at idle. its been up to *250. I've got autometer tach/volts/oil/water temp gauges

It has all LA accessories/timing cover/water pump etc on it.
 
Is the radiator cap new? What % of the fan is inside the shroud? Are you sure the fan is pulling air and not pushing (wrong fan)? Sure does seem odd. I guess it could be running lean too but I am not a carb guy!
 
Overheating at idle means your fan is not pulling enough air.
Are you sure the fan is pulling air through the radiator?
 
Wrong fan makes sense. If you have a Magnum why are you running LA head gaskets?
 
Steve I'd first verify that the gauge is reading correctly. I know it's an AutoMeter but you just never know. I have one of those infrared temp guns I use to check temp gauge accuracy with. If it is 250 degrees, that is extremely hot and you will know it as soon as you pop the hood a blast of hot air will hit you.

Other than that make sure you have good air movement through the radiator. Make sure the clutch isn't bad on the fan. Also as 71dartguy asked, how much is the fan sticking into the shroud? It should be about 3/4 to 1 inch from the radiator (in other words most of it should be inside the shroud) and should have just enough clearance around the fan blade to clear the shroud.
 
Does the upper hose get hot. If so, this would prove that the thermostat is opening.

How long does it take to overheat after an overnight cold start?

If it is within 5-10 minutes, you could have a thermostat or air pocket problem.

Some more info on the overheating will help us diagnose this.
 
air pockets could also indicate a combustion leak (bad head gasket, warped head, crack). but if that was the case it would overheat all the time. idle only overheating is lack of airflow.
 
Your - belongs to you
You're - You are
Its - Belongs to it
It's - It is
Brake - Slows your car
Break - Falls apart
There - Not here
Their - Not yours
Here - Not there
Hear - To perceive sound
Lose - To not win
Loose - Not tight
To - Where you're going
Too - It's not where you're going and it's not two, too!


Like that!
 
It's really all pretty simple....use your hand to feel the amount of heat being blown back behind the fan @ idle.....AND the AMOUNT of air as well. I'd run it with the rad cap off until it warms up and see what kind of flow you're getting while revving it up a bit and holding it at around 1500 RPM's, all the while feeling what kind of heat is being given off.....blown back.
 
cudavert said:
It's really all pretty simple....use your hand to feel the amount of heat being blown back behind the fan @ idle.....AND the AMOUNT of air as well. I'd run it with the rad cap off until it warms up and see what kind of flow you're getting while revving it up a bit and holding it at around 1500 RPM's, all the while feeling what kind of heat is being given off.....blown back.
Click to expand...


I think he has a handle on that much...he's just frustrated and missing something.

Now, we have another to add to that list from earlier in this thread!!! Thanx! LOL

RPM!!! - Revolutions Per Minute, No "'s"!!! LOL
 
To see if your not pushing enought air put a fan in front of the car at idle and see if that cools it down.
 
Just a thought but sometimes when the thermostat opens the rush of waterflow collapses the lower radiator hose (broken ,corroded inner spring in hose) thus cutting off water flow.
 
Your - belongs to you
You're - You are
Its - Belongs to it
It's - It is
Brake - Slows your car
Break - Falls apart
There - Not here
Their - Not yours
Here - Not there
Hear - To perceive sound
Lose - To not win
Loose - Not tight
To - Where you're going
Too - It's not where you're going and it's not two, too!
RPM!!! - Revolutions Per Minute, No "'s"!!! LOL
 
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