Temperature Gauge Reads High After New 302
 

For those that don't know, I recently dropped a new 302 T5 etc into my 65 that started life as a 200 3 speed.

Anyway, The temperature gauge reads about 90 percent of the scale and the thermostat wasn't even open. This was the second time we ran it with the radiator cap on. After cooling down it doesn't appear that it took any more coolant in.

Keep in mind that this is all under initial startup with radiator cap off. We didn't have the cooling stystem completely full and were trying to fill it up. This time the gauge was pegged out at max H.

I am wondering if the sending unit is the problem. I have all new stock style gauges. They are the long speedo with the 120 mph speedo and fuel and temp gauges with warning lights for oil and alt. Could it be that the sending unit I got from CJ Pony part number HW1316 is the wrong one? It says 65 all for warning lights etc. I would link to their page, but the links never work for that website. Just search that part number at CJ if you want to see it.

Could the problem also be that my 302 has a 180 thermostat in it? I thought that the older engines had like 160 or 165 stats. If so, what sending unit can I use that will read close to right?

We used an infarred thermometer and could only get 160 degrees at the hotest spot on the motor. I'm not sure how accurate our test was though.

:confused:

make sure the engine is full with water, mayeb you have air pockets
make sure you have the temperature gauge hokked up the right way round. If you have the two cables swapped at the cluster you might run into such a problem.
my cars engine was not cooled properly. the 64-65 radiators are tiny.
i got an aluminum one but still have to upgrade the fan to keep it cool in idle.
what is weird is that you say the thermostat never opens.

the old fords only use two different types of thermo sensors. the one you have 64-65 and a bigger threaded one for 66+. I'm wondering how you got to fit the small one. what intake do you have?

I was thinking that maybe there are air pockets. Would the air pockets create steam which would make the sending unit hotter?

I have an Edelbrock intake and installed the temp sending unit in the front driverside location.

I have an aluminum Fluidyne radiator.

Also on another not the heater doesn't seem to produce much more than luke warm air. I remember years ago with my 6 cylinder the heater didn't put out much heat then, so maybe thats an inherint issue with these heaters. I also noticed that the heater hoses were not nearly as warm as the radiator hoses etc.

It also seems like the thermostat will open and then close fairly quickly.

The sending units are different depending on if you have a lightor gauge. Maybe they sent the wrong one. You might try picking up a gauge at the local parts store and seeing what it says. You dont have the reverse rotation pump do you?

ya. radiator hoses hotter than heater hoses is odd. at the same time, how do you know the thermostat is not opening? if the radiator hoses are hot I'd say it's open alright.
i don't know anything abou treverse rotation pumps but might be somethign to look into

How about getting a real temp gage? Not an electrical one...a mechanical one.

I have a reverse rotation water pump. What would the issue be with this setup?

I discovered that somehow the new heater core is clogged. So, I temporarily bypassed it. The hose I used to bypass it gets just about as hot as the radiator hoses. I ordered another new heater core. I have had that one too long to send it back.

I am trying to keep a somewhat stock appearance and really didn't want a whole bunch of gauges. However, We are probably going to get some aftermarket gauges at some point. Right now the budget does not allow for that. We have spent alot of money on it recently. I may end up picking up a gauge this weekend though.

I would like for the stock gauges to at least read close to normal though.

The fuel gauge seems to read right.

I am still wondering if the fact that I have a 180 thermostat is part of the issue with the gauge reading high.

I remember that ours had a 160 thermostat in it when it was a 200. Didn't most of the older style engines have cooler thermostats?

If this is part of the problem is there a different sending unit that will compensate for this?