need more heat; stang runs cool

Charlie1 · 10-21-2009, 03:06 PM

I got my 66 convert with a 200 cid six about 5 years ago. I did a heavy chem flush on the cooling system and replaced antifreeze since PO couldn't remember the last time he changed it. I put in a new water pump and a 180 thermostat. Radiator was replaced about 10-15 years ago, it appears. Since I did that work, on the temp gauge, the needle consistently has been at about the one-fourth mark into the operating range, great for summer in Minn. In cool weather (40s), it runs a little cooler than that, barely into the operating range.

Heater never throws much more than luke warm air, as a result. Last week, I put in a 195 thermostat (standard equipment) and engine ran cooler yet. I figured it was defective, got another one, and got some improvement (back to just into the operating range), but not much.

What's going on? Would my antifreeze mixture influence operating temp? I might have too strong a mix in there, like 80/20. Or is the whole system just too efficient now?

This ad is not displayed to registered or logged-in members.
Register your free account today and become a member on Mustang Forums!

nba1341 · 10-21-2009, 03:20 PM

i wish my car would run too cool lol!

THUMPIN455 · 10-21-2009, 03:24 PM

Do you have a candy thermometer? If not you can pick one up at the grocery store. Put a pot of water on the stove, drop in the thermostat and heat it with the thermometer in the pot. Note the temperature that the thermostat begins to open, with the 195 it should start to open at 195. If it opens sooner, then get another one. I have the same problems sometimes, and finding the right thermostat that actually works like its supposed to usually cures it. You cant have too efficient of a cooling system, the thermostat is supposed to keep the water flow moving at the speed that keeps the engine in the right operating range. When its too hot it opens allowing more water through, too cold it closes and holds the water in the engine longer.

Where do your heater hoses connect to the engine? Or does one connect to the radiator? I dont have any straight sixes so I dont know the layout. One should come from the back of the head, and the other around the water pump if its like most engines. If its connected to the radiator and water pump, it wont get warm enough water to heat the car. If you dont have AC you could also have a vent open in the car, or the cowl could be letting cold air in through rust holes.

It never got warm here in the UP this year, only had three days all summer over 85. I think its gonna be a rough winter with lots of snow.

2+2GT · 10-21-2009, 04:16 PM

First and foremost, these engines were designed to run on a 190° thermostat, so get a genuine Ford unit and use it.

sixt5 · 10-21-2009, 05:44 PM

possibly an air pocket in the system. had this happen to my old toyota pickup. ran fine, just no hot heat.

tx65coupe · 10-22-2009, 05:17 AM

When my 65 was still a I6 with a 3 speed (before the V8), it did just about the exact same thing your talking about. I just decided to live with it since it wasn't overheating. It was setup the same way.

If you really want to know what temp it is running at get an infarred thermometer like this. I have it and think its great to have. I think Advance has something similar.

http://www.summitracing.com/parts/SID-MT-100/

Even now with the 302 T5 conversion, it runs warm and about right when its warm weather. When its cool outside the heater blows warm but not hot air.

kalli · 10-22-2009, 07:15 AM

ya. check with a thermometer. Who knows what your gauge is showing ...
infrared thermomers are cheap. if it runs too cold then get a different thermostat

4reboy · 10-22-2009, 02:11 PM

I think I have a 160° one in mine and it still runs warm and almost over heated a few times in the summer.

Weird how things like that vary among cars

eZ · 10-22-2009, 03:44 PM

I would increase the HP output of the motor to get it running hotter LOL

rmodel65 · 10-22-2009, 07:21 PM

whats a heater and why do you need one?