I have been looking for a water temp sensor with 1/2" threads to fit my edelbrock intake without an adapter. I found one that has this description:

ADDITIONAL DETAILS
Connector Gender: Male
Functions: Switch
Terminal Gender: Male
Terminal Type: Blade
Temperature (Deg F): 210 Degree


I guess that means that is the max the temp gauge can handle (210).

I can't find the overheating temp of a 302 or a manual to look at (I found a lot of overheating temps, but they are different for different engines.) My gauge has l to H and so I don't know if this will work for that application. Thanks!

 

Well, the 302 in this error came with a 185 degree thermostat. I run a 160 degree one as I am in the southwest and never need to warm the truck up. 210 is right at the border line of overheating. At that temp, you would normally here the coolant moving into the overflow.

 

I don't understand why you seem to be looking at generic sending units and not ones designed for your engine?

 

Just like the fuel gauge sender, the temp and oil pressure senders need to be designed for the particular dash gauge they are wired to.

A sensor having one set temp sounds more like a temperature switch rather than a sending unit. The switch will close at 210F while a sending unit that drives a gauge will have a variable resistance.

After all that, you are going to have to use the stock sending unit for your truck and use a adapter, I know of no way around it. If it were me and I cared about my truck and it's well being, I would ditch the useless factory gauges and go with something aftermarket with real numbers on the face of the gauge.

 

Because my engine is a 79 LTD II and gauge is a '86 Bronco and the intake manifold is 1/2" opening (without adapter) and I don't know which will work for all of those specifications. Would a 86 Bronco sender that works with the gauge also work with the LTD II engine?

 

And the original Bronco engine was a v6 1 barrel 4.9 liter.

 

Stock sending units are not accurate unless dialed in with an aftermarket sensor / gage. Period...

230-240'ish is when damage starts to occur in a 302. Usually the head gasket is the first to go.

It's become obvious to me that most of the folks (from colder climates) think that running hotter is ideal for combustion due to hear-say. In the south it is far proven the opposite for a non-emission vehicle. I too have hopped onboard with everybody else around here that runs 160.

The reasoning: Keep in mind that the temperature at the inlet is ALWAYS cooler than the rest of the motor due to the thermostat starts to open up at it's rated temp and the rest of the motor doesn't feel the cooling until later. The entire motor is inconsistent when it comes to temperature. The damage for a 302 mostly occurs between #2 and #3 and between #6 and #7 cylinders. That is the furthest point of quench from the water passages. So if your thermostat malfunctions and doesn't start to open til 210, the quench is not felt between the cylinders and can reach the damage point before it feels the quench.

Not until You tube / recently that technology has proceeded to turn the vision of (some) die-hard mechanics around to see the light when it comes to thermostats and engine temps. Although very obvious by law of common sense, it's only begun to be proven recently by people placing temp sensors in weird places. I'd say even 80% still think you need a 195+ degree thermostat. It is strictly a regional matter. When temps reach 100 in the south, the air is more like 105-110. Direct metal from the vehicle can reach 120+ and carry on into the engine compartment. So the outside temperature becomes a huge factor.

210 is most commonly used for a redline due to the delayed quench reaching more like 230+.

 

If it was a 4.9 it was a inline six, just to let you know. The sending unit from the six will work fine with your LTD 302. Just use an adapter and it usually goes in one of the holes on either side of the themostat in the intake manifold. The probe on the sending unit dips down into the coolant flowing across the intake coolant ports on the front.

 

So do I need some kind of adjustable sender? I found some for a 86 Bronco, but don't know if they will work. I got a new 185 thermostat, but I'll trade that in for a 160 now. I'm in Alabama and today the heat index is 107. Trying to work on that truck (which is in dead sunlight where I can work on it) is warm to say the least. I think the direct metal gets more like 200! I can't believe its not cherry red.

 

I would not run a 160 thermostat. The engine needs to warm up enough to boil off the water and fuel out of the oil. It's a known fact that a engine that runs too cool wears faster.

 

Where are you located? I, too, am in Alabama and have no problems running the stock 195F thermostat [with my 4.9L engine].

 

Just East of Montgomery. Radio said heat index 107 and to limit exposure outdoors.

 

Where do I look for original parts such as the temp sensor? Do I just enter my truck somewhere like RockAuto?

 

Any on line parts stores. They may not be Motorcraft but they should work for your truck.


Now you just told us the truck had a 300/4.9 six and you are installing a 78 302/5.0 from an LTD (not that that make any difference) as a 302 is a 302.


Now as some one said you can use the senders from the 4.9 in the 5.0 and not worry if they will work or not as they should have when the six was in the motor bay.


With all after market intakes you will need to use an adaptor for the temp senders unlike the stock intake.
Put a little sealer on the threads do not use sealing tape on the threads as it will keep the sender & adaptor from grounding and work.
Dave ----

 

The engine does not care which sending unit is installed. Use the one that matches the gauge.