greystallion66

Hey guys, I recently installed a Hot Rod Air electric fan that is rated at 2500 cfm, a 160 degree thermostat, and have an aftermarket 4 core radiator (not aluminum). My problem is that my car still tends to heat up. I just flushed the radiator and added the correct mixture of antifreeze and distilled water, along with water wetter. The car heats up when I am constantly driving, and when I am in traffic. Is there any way to get my car to run extremely cool? I am going to be driving my car daily soon. It needs to be able to run in 110 degree weather, because it gets that hot on july and august days where I am at. Any help would be appreciated.
Thanks

Aussie66Fastback

is it a 6 or 8
when you say "flushed" the radiator, do you mean tanks off by a rad shop or just stick the garden hose in?
Do you still have the original fan in place?
is the electric fan wired in reverse?
does it cool down at highway speed or still a problem?

most electric fans only assist at low speed and the car's forward movement makes the fan redundant at speed.
if you replaced the rad on an old motor that has been sitting around, chances are that the heater core or block has let loose a heap of gunk that has reblocked your radiator.

the other problem is, for unknown reasons, many replacement thermostats fail. it could also be installed back to front. havev you tested it?

when you refilled it, did you allow time for the engine to warm up and check it again? there will often be an airlock until the thermostat completely opens and then the coolant level "drops" requiring top up.

sure sounds like a blocked system

greystallion66

I have a 289. And I used the garden hose to flush the radiator out. I was driving around my town anywhere from 30 to 60 miles an hour and the radiator would be right at midline then creep up, then return to midline, and again creep up. I did check the radiator after a 20 min test drive. The system did not require me to fill anymore radiator fluid to it. The engine does not have the original fan on there. The electric fan was put inplace of the factory fan. As far as the rotation of the fan I will have to check that. I had a local shop install the fan for me since I am a bone head with wiring.

Soaring

Get a 180 degree thermostat, an overflow tank, and a shroud. Also check your rad cap to make sure it is 13 pounds.

Cannonball888

If your HotRodAir fan is for a '65-66 Mustang and has a intergral shroud it is actually made by Derale. HotRod Air just adds brackets, a thermostat, and a relay. I have the same unit and it works great. Your problem isn't the fan unless it's just not coming on.

slickman

You must have something going on with the radiator regarding a blockage. Check that the heater core is flowing well and that you're water pump is good. I'm running a 3 core aluminum, high flow water pump and a 160 therm and it has NEVER gone above 165...

dodgestang

Please define heats up. What is the temp it is reaching. If you start typing....."the needle gets close to the H" please go buy an accurate temp gauge.

As soaring pointed out you should be running a 180 or a 195 thermostat. The purpose of the thermostat is to regulate the flow of water into the radiator and in a perfect world opens and closes all the time. Water heats up to 180...thermo opens.....hot water goes into radiator....cold water comes out of radiator....temp goes down...thermo closes.....hot water in radaitor cools down in air flow....temp goes up..hot water goes into radiator...colder water comes out....and on and on and on.

So with the 160 you are attempting to regulate water flow at a temp berlow the thermal capacity/mass/what ever catchy phrase fits of your system which is cause it to run hot.

Since you have said 'heats up while driving or in stop and go traffic' you possibly have multiple problems or just one.

1. Accurate gauge that reads temp is required

After that is installed you can better troubleshoot.

However.....

Heating up in traffic is caused by:
a. not enough air flow over the radiator
b. not enough water flow in the system
c. not enough physical capacity in the system to cool the engine

Heating up at highway speed is cause by:
b. not enough water flow in the system
c. not enough physical capacity in the system to cool the engine

Now the 65/6 mustangs are notorious because of their small radiator design but a good 4 row brass core radiator is more than enough to cool a 289 so you should be able to eliminate c from the list

That leaves a and b to address.

You say you have a new high flow fan. Did you install this is a pusher or puller position?
When was the last time you replaced the water pump? If you recently replaced it, did they give you a later model 302 version that spins the wrong way? If you can't remember, replace it.
When was the last time you had a full cooling system flush? Radiators rust, so you put a new one in. Guess what...blocks rust to and all the old drud from the old radiator also finds its way into the block. Get the whole system cleaned out.
Do you have a spring in your lower radiator hose? This is a common and often overlooked and hard to trouble shoot item...the thermo opens water starts flowing and a pressure is built up in the system sucking the lower radiator hose closed if it doesn't have a spring and/or sufficient internal rigidity.



Please also note that this is simple troubleshooting for the cooling system...and with the information provide we all have to assume this where the problem is.....however....

Poorly tuned car with timing screwed up will cause overheating all the time
Poorly tuned carb with poor idle mixture and jetting will cause overheating all the time
Performance auto trans with high stall constantly run below stall speed (3k stall, running at 1800 RPM) will cause heat up and if plumbed into the radiator will cause the car to overheat because of thermal capacity issues
Rattle can rebuild of a radiator done wrong will cause heat up (look I painted it black so it looks nicer)
10 billion bugs in the fins will cause heat up
etc