Overheating mach 1! Help pleaseee :P

[klx_boy]

Hey everyone, im the proud owner of a 1970 Mustang 351 Mach 1 Cleveland.
First things first, when the cars cold it starts fine and dosent skip a beat.
When the cars hot it dosent want to run and "chuggs". Then when i take my foot off the gas or put it in neautral after 10 or so seconds the car stalls and the engine is red hot.
It has an auxillary(electric) fan aswell as the original that runs off the motor.
Any suggestions of why it may be over heating? its a new car so i am going to flush the system but need your thoughts and oppinons as over here in the U.K people dont know much about them.
Thanks for all your help in advance, another new mustang owner

 

[19stang66]

I'd just like to say welcome and I know that someone will answer your question. I dont know a lot about your style of car/engine.

 

[jdowen2]

Get a new radiator cap.

 

[grego37]

if your electric fan is in front od the radiator , id get rid of it. Allot of times a fan up front hurts air flow.
i'd concentrate on the engine fan, and make sure it has a proper fan shroud.
Id start there and see what happens.

is it hot all the time?
how hot is it cruising around town?
how hot s it above on the highway?

other causes:
bad radiator cap
a leak in the system (wont hold pressure)
Faulty thermostat
bad waterpump
underdrive pulleys
carb. too lean.
to name a few.

 

[TOM B]

A few thoughts, distributor timing is way advanced,,, this could be why it runs so good cold and then overheats and stalls when hot.
2)check that the engine fan is on correct and not installed backwards, it should also have a fan shroud with about 1/4 of the blade sticking out of the shroud. 3) no thermostat,, someone may have taken it out, a thermostat is there to hold back the coolant till the engine gets wormed up then opens just enough to let the hot coolant out and the cool in, if someone took it out then the engine just keeps on getting hotter and hotter because there no control there to keep the coolant in the radiator long enough to cool down.
4) radiator cloged up, look into the radiator cap and see if hard white deposits are cloging the tubes.
5) check you radiator hoses, when hot see if the are collapsed,is that spelled right)
6)water pump shot, when COLD take off the radiator cap and start the engine, you should see the coolant flowing a little from the bypass hose.
7) blown head gasket, if you have a blown head gasket, air or compression might be getting into you radiator and it wont cool right, one way to check
this is to take off the radiator cap when cold and start the engine, look to see if there are air bubbles in the coolant or when the engine is cold start it first and wait 20 seconds the take off the cap SLOWLY and if there is pressure the you have a leek.
8) head gaskets on wrong.
LOOK FOR THE SIMPLE THINGS FIRST
The last owner had a overheating problem and thats why he added the electric fan.

 

[klx_boy]

Thanks for all your help. As i didnt feel safe driving it 300 miles back to my house on mostly jammed busy motor ways i have it coming up to my house on a low loader(I get it friday) so will get the radiator flushed and check that the radiator cap is fine.

 

[klx_boy]

bump

 

[Gud T.B. Blown]

another simple thing to check is to see if you have the correct thermostat. it's not uncommon to ask for a cleveland thermostat and get one for a windsor instead. the windsor thermostat will fit in the housing but will not open.