Idling hot

[340GTSport]

I’m going to go try and help a friend fix his 69 dart . that is over heating while parked or at a light.

After we do a few things to try and fix it. How long would think we should let it idle . So I can make sure it’s not going to get hot
On him once I’m no longer there . Or the next time he drives the car to go someplace ?

Car is a 69 dart ,340 auto , no a/c

 

[toolmanmike]

Until it overheats, or doesn't. A properly working system should be able to idle for days and not overheat. Does he have a radically built engine? Many questions about what fan. shroud, bad radiator cap, or thermostat. And that's just the beginning.

 

[340GTSport]

Until it overheats, or doesn't. A properly working system should be able to idle for days and not overheat. Does he have a radically built engine? Many questions about what fan. shroud, bad radiator cap, or thermostat. And that's just beginning.

Are u ok !!!!! Wasn’t sure if something was wrong with u or what ! Any way im just saying how long would u wait to see if it get hot ? So u would wait 10 mins then leave a say it’s good . A let some one blow a head gasket or worse ?

 

[toolmanmike]

Are u ok !!!!! Wasn’t sure if something was wrong with u or what ! Any way im just saying how long would u wait to see if it get hot ? So u would wait 10 mins then leave a say it’s good . A let some one blow a head gasket or worse ?

No, I was serious as a heart attack. First, is it heating up at stop lights, temp just rising but not boiling over? How hot does it get before your friend pops it in neutral and revvs the engine to get more air flow? I haven't seen any answers to my questions above. Idle it 5 min, may be 10. Will it overheat at 15? You don't know until you try.

 

[CRUZE 418]

There are several things to know here, how long should it take to overheat isn't one of them.
Radiator, cap, aluminum or copper
Fan clutch type or straight fan
Water pump type and brand
Thermostat
Built 340, stock
Has it always overheated, or something new
The engine should idle forever without out overheating, or the camshaft fails, or runs out of gas.

 

[340GTSport]

Ok I’ll try a find out more , cause I don’t know all the ends an outs about the car . He liked mine a ran out a bought a car .

 

[Newbomb Turk]

Ok I’ll try a find out more , cause I don’t know all the ends an outs about the car . He liked mine a ran out a bought a car .

Until you know more about the car everything is a guess. I don’t think there is ever a need for the engine to see over 200. Im in the minority for sure.

You have no idea what his idle timing is and thats a first place to look. Is the radiator plugged? How fast is the water pump turning relative to the crank?

 

[George Jets]

Please tell me he does not have an Electric Fan.

And the accompanying flat cookie sheet flat shroud blocking any air that should be flowing through the radiator.


☆☆☆☆☆

 

[RustyRatRod]

Tons more info needed. You may as well have said "Help, my friend's car is overheating. It's red".

 

[Inertia]

Take a temp gun, and shoot the temps at the top and bottom rad hose fittings, - not hoses, - when it gets hot.
That'll tell us if the rad is working .

 

[Illahe]

I’m going to go try and help a friend fix his 69 dart . that is over heating while parked or at a light.

After we do a few things to try and fix it. How long would think we should let it idle . So I can make sure it’s not going to get hot
On him once I’m no longer there . Or the next time he drives the car to go someplace ?

Car is a 69 dart ,340 auto , no a/c

Start by confirming that the initial timing is in spec. And put a fan in front of the car after you know your "timing is in spec for the camshaft duration @.050." Look at:FBO Ignition - Home of the HRR688 - Racer Brown Cams for initial timing specs. I have had pretty good luck with this chart.

 

[Dana67Dart]

To answer your question...

As long as it takes for the temp to stabilize. Let's say it takes 10 minutes to get to 200. If it stays at 200 for another 10 minutes I would say it's good.


But many factors are in play.

If it's an automatic have it in drive, that way transmission heat is added to the system. An automatic is rarely put into neutral under normal driving conditions.

The outside air temp can have an effect. So if it's 50 deg outside maybe it gets to 190. If it's 90 deg outside maybe it gets to 210.

The key is what does it maintain in drive at a standstill.

And testing will be the only way to know

 

[AJ/FormS]

Just so you know what's possible;
once up to operating temp, my system runs at 207*F exactly, no matter what; never more. I can even parade it, in gear and pulling itself, at 550rpm, with just 5* Adv.
My "secret" is in
the Thermostatic clutch, and the overkill
7-blade, hi-attack angle, all-steel fan.

When you are driveway testing, close the doggone hood.

 

[crackedback]

Lack of initial timing will drive up exhaust temps, transfer into heads/water. If you don't need to pass smog testing, throw the "book" numbers in the trash and give the engine what it wants for intial and tailor the rest of the ignition curve. Doing it right takes work, it's not going to be loosen a bolt, twist and move on exercise.

Fan shroud is important too.

 

[mbaird]

Lack of initial timing will drive up exhaust temps, transfer into heads/water. If you don't need to pass smog testing, throw the "book" numbers in the trash and give the engine what it wants for intial and tailor the rest of the ignition curve. Doing it right takes work, it's not going to be loosen a bolt, twist and move on exercise.

Fan shroud is important too.

What he said ….
Probably factory timing and vacuum advance hooked up to ported instead of manifold. Try hooking the VA to manifold vacuum first .
If you increase the base timing and use ported vacuum then you will have too much total mechanical and will have to recurve the distributor.

 

[340GTSport]

I’m sorry I guess I should have worded the post differently . I’m not asking how to fix it . I’m just worried that , I will think I have it fixed . Then he take it out a blow a head gasket or worse .

How long should I let it run to see if it’s gonna get hot ?

I think we got it fixed . Put a new radiator cap and thermostat gasket as it was leaking. A flushed system it was nasty. Then let it idle for about 25 minutes. It doesn’t seem to got hot now but I just worry .
How long do u let it run to see if u have got the problem solved ?

 

[Dana67Dart]

How long do u let it run to see if u have got the problem solved

Post 12 is what I do.

If in 25 minutes it raised tona temp and stayed there it's probably good

 

[340GTSport]

Post 12 is what I do.

If in 25 minutes it raised tona temp and stayed there it's probably good

Thank u , sorry I just replied an had not been back on since post 8. A see all the people responding a wanted to clear things up . Before more people replied.

 

[mbaird]

Take it for a drive then let it idle for 5 minutes. Driving will bring it up to temp faster . And it will be fun !

 

[Bewy]

If 'nasty' [ post #16 ] means there was a lot crap coming out when you flushed the system, then there is a good chance that the rad core is blocked & causing o'heating.