Fox 1991 302 Fox Running Hot

Adam B · May 22, 2016

I have a 1991 LX with a 302 with B cam, C4 trans. Just a basic bolt on car with nitrous. When the car sits at idle for about 10 minutes it will get up to around 230-250 degrees. If you run it down the road it cools down some but will warm back up, even when cruising at speed it will get back up to 220-230 degrees. The car has new headgaskets, new water pump, electric fan, aluminum radiator, new thermostat, new radiator cap. Is there something I could be missing here? The car isn't loosing coolant, the top radiator hose will suck itself together sometimes after the car sits after driving it but not all the time.

Any help will be greatly appreciated.

Thanks

mikestang63 · May 22, 2016

if the car runs hot at idle or in stop and go, then it is most likely an air flow or water pump.

A few questions
1 was all the air burped out of the system
2. what fans are you using
3. are you running underdrive pulleys
4. do you have an overflow bottle

a91what · May 22, 2016

And....... sorry have to ask... which direction did you face the spring on the thermostat?

Adam B · May 23, 2016

mikestang63 said:
if the car runs hot at idle or in stop and go, then it is most likely an air flow or water pump.

A few questions
1 was all the air burped out of the system
2. what fans are you using
3. are you running underdrive pulleys
4. do you have an overflow bottle

I thought water pump too, this is the 3rd one we have changed. No underdrive pulleys, I did delete the A/C though. Yes, there is a overflow bottle on the car. I have a attached a picture of the fan on the car, I am wondering if it needs a better shroud? What is your process on burping the system?

a91what · May 23, 2016

Uhh yeah. You need a shroud and at least 1800 cfm of air movement.

mikestang63 · May 23, 2016

Adam B said:
I thought water pump too, this is the 3rd one we have changed. No underdrive pulleys, I did delete the A/C though. Yes, there is a overflow bottle on the car. I have a attached a picture of the fan on the car, I am wondering if it needs a better shroud? What is your process on burping the system?

that fan is most likely your problem.
1. it doesnt cover 1/2 the surface area of the radiator
2. there is no shroud
3. I bet it doesnt pull sufficient CFM You want at least 2500 cfm. The stock clutch fan pulls 3000.

I didnt ask about A/C delete. If you are running an underdrive crank and water pump pulley, remove them and put the stock ones back on. They are a waste of money and cause cooling problems.

EIther put a stock clutch fan back on or get a mid 90's v6 3.0liter Taurus fan and a flex a lite 33054 controller, and I bet your problem will be solved.

These cars are nottorious for trapping air in them If you don't burp the air out of the system. Go and get a Lisle funnel and then with the car cold

using the proper cap opening adapter attach it to the radiator opening and fill the funnel up with 50/50.leave the plug for the funnel out
start the car, turn the heat and fan on high and let it get up to operating temperature. it will take a few minutes
when the thermosat opens, you will see the level drop in the funnel when the thermostat opens and bubbles come up.the upper hose will be hot when the stat opens
fill the funnel up as needed. do not let the funnel drain out or you will suck in air
when the system does not produce any more bubbles, turn the car off
put the plug into the funnel and remove the funnel
put the radiator cap back on the radiator
you are done

Much easier than having to jack up the front of the car

aztecgwynn · May 25, 2016

I agree with mikesstang63 buy the Lisle funnel and do what he suggests!
My 5.0 was doing the same but used Lisle funnel 1 morning and was amazed all bubbles that came out and it took me about 45 minutes to clear air bubbles out. Now my mustang has no cooling issues only when sitting at light for long periods of time and I mean long periods of time!!

cleanLX · May 26, 2016

are you running with the spout out and locked timing?

Adam B · Jun 11, 2016

Did the Taurus fan and FAL controller. Seems to have fixed my cooling problems. Let the car sit outside at idle for an hour and it never went over 180*.

Thanks

mikestang63 · Jun 11, 2016

glad it worked for you. The invoice is in the mail

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