I have a 1994 F150 5.0 4x4, a couple of weeks ago it got down to -13 here in ohio and my truck died on me coming home from work. Yesterday i went out and it started fine. After letting in run for about 20 min, the temp gauge continued to climb and when i put it in drive the oil pressure guage began to jump from normal pressure to no pressure.

any thoughts? I am not a mechanic but was thinking it could be radiator or water pump?

 

First off check your oil level I know if my truck gets low on oil it does that in the cold also check your anti freeze make sure it the right mix and won't freeze over.

 

that was my first thought as well, when it started to warm up last week i drained the antifreeze that i could out and put new in, and it did the same thing.

 

On the oil pressure suddenly dropping to 0, I'd check the connection at the sending unit. I had no oil pressure one day, lost connection at the sending unit.

Very well could just be your t-stat is stuck closed on the cooling issue. That's where I'd start. See if your upper radiator hose is getting hot, if not the t=stat isn't opening. Another way, remove the radiator cap slowly! when engine is cool! crank it up and watch for flow as engine starts to warm up, again the upper hose should start to warm up as well.

 

Great I will try that this morning. Does anyone know if there is an auto shut off or anything that would make the truck die when it overheats? I still dont understand why I had to tow it home for it to run now that it is home.

 

OK, i did this test and the hose was ice cold even with the temp guage showing overheated and I never saw any flow. How do I fix the t-stat so that it will open properly?

 

No way to "fix it".
Just install a new one.

 

ok, where is the t-stat and how hard of an install is it?

 

Follow the upper radiator hose back to the engine.
It attaches to a 'thermostat housing', this is attached to the engine with two bolts.
First, drain some of the coolant from the tap at the bottom of the radiator.
Remove the two bolts securing the housing, remove the thermostat, scrape the old gasket off both sealing surfaces.
Replace in the reverse order.
(make sure to install the thermostat "right side up")
Open the radiator cap and start the engine. Fill the radiator with coolant.
When the thermostat open the coolant level should drop again. Refill with coolant and fill the coolant overflow catch bottle to the lower "cold fill" line.

Replace the radiator cap, restart the engine and allow it to reach operating temperature.
Check for leaks.

You're done

On edit:
I really don't know about later smallblocks but I do know that some 460's disable the fuel pumps if the oil pressure drops too low.

 

Did you have oil pressure this morning when you had it running?

I recommend picking up a Haynes manual when you get your t-stat. It can really help you out a lot.

Get a good t-stat, like a Stant Superstat

 

The stock oil pressure guage is just an idiot light!!! It will jump right to the middle of "normal" as soon as the sensor reads above 5lbs pressure. you want an accurate reading do not trust that guage. Mine was reading "normal" Installed an aftermarket one i had, and i was really down to 10psi at idle, 15 at 2k rpms. Never would have known if i didnt install a working guage

 

I installed the new t-stat yesterday and the truck is still over heating. It gets very hot after about 15 min of run time. I am thinking radiator. Any thoughts?

Oil pressure seems ok, the truck is having some trouble starting but runs fine once it turns over.

 

Only you can tell if it's the radiator, did you look inside it before when it was low? Did it look all gunked up? Maybe the water pump is bad. impeller came off the shaft or something.

If you run w/o the radiator cap on, do you see any flow at all as it warms up?

 

Yes I can see flow, the water pump is pumping coolant through. It just keeps getting hotter and hotter the longer it runs.

 

Cracked head?