Yesterday I leave the house and 200 yards down the road my oil pressure/heat light comes on in my truck. I stop, shut truck off (still in the hood) pull out the scanner and scan for codes even though I figured it would have none. It didn't. Start truck back up and it stays off. Late for a meeting - drive 4 miles to said meeting - spend 5 hours there - drive home. Check oil it's 3/4 way up on the hash marks, I don't add any oil - clean and looks great on the stick. Check coolant level after 3 hours sitting and cooling and it's maybe an inch low from minimum cold level. Fill it up the rests of the way and call it good for now. Today does the same thing, shut truck off, restart never comes back - drove for 20 miles or so; stop and go.

Recent things done to truck.

1. 2 weeks ago flushed coolant, and replaced. - Assuming I had a little air still burping out so that's why I was a tad low but no way the engine could be hot since I had gone 200 yards. Temp gauge was barely off the bottom yet.

2. 2 days ago I sprayed the entire under body of my truck with fluid film to protect from winter salted roads. Could I have soaked the sensor a little too much? Where the heck is it, looked briefly but am not finding it with my eyes, and have a computer down so my Ford manual is not functional - CD only works on the big computer not the laptop.

3. Not really service but, but been having electrical issues with only the #3 fuse in my truck. Keeps blowing. Controls OBD and the dash power port. Been meaning to address that but haven't had time. Work just won't let up and allow me much time lately.

So if this happens again tomorrow do I head down 1, 2 or 3 as the most likely cause? Throw in a #4 coincidental cause if you got one....

 

Our trucks don't have a oil pressure light so I assume you mean the coolant temp light, My guess would be sticking thermostat,,,

 

This is the light, and what my in truck owner's manual shows the light means. So if we don't have sensors why is there a oil can with a drop of oil out of it, and a description of an oil pressure issue? I hate those idiot lights.

 

Because I totally spaced out and forgot about the oil pressure gauge and light, Mine is in storage for the winter so I haven't driven it for a while to jog my memory. With both lights coming on I don't think it is a stat issue now but more of a PCM or wiring issue. I guess I would fix the problem with the OBD / power point issue and go from there...

 

Does it go into limp mode when the light comes on ?

 

Nope. Was just 200 yards down the road wasn't even warm yet both times. Felt fine. Shut truck off and restarted it - light didn't come back on and didn't notice any performance issue. Coolant was about an 1" low the 1st day but no way it could have been hot yet in that distance - outside temp was about 35 degrees at the time.

Edit: that first day I went to a meeting it sat 3-4 hours started it again no light - drove home. Then this morning after sitting all night it was back on if that adds anything to the equation IDK.

 

Air in the coolant lines after the flush? No clue; just making a guess.

 

Sounds like limp mode you didn't say it runs slowly after it quits and restart. Try taking the hose off the intake manifold pass side front and add water until it comes out there to burp, also change your thermostat. If it sticks it will quickly heat up, the temp gauge will peg itself, the oil light will come on, and the engine will shut down. When you restart it it will be in limp mode. Search "limp mode". Mine went into limp mode in one mile and the thermostat wasn't even sticking, it just opened too late.
You said it's just a light problem but if you keep driving it like that it might shut down or go into limp. The first time it happened to me I just got up on the freeway a mile away and it suddenly shut down at 60 mph and when I pulled over to my surprise it was idling so I took off and it was running on 5 cylinders, shut it down, restart, and it was fine for another mile and repeated it. If it is going into limp your engine is actually very hot inside but there are no signs of it.

It might just be a pre-limp glitch, mine did that first coming to think of it. Running low on water will put into limp so I would burp it first.

The oil sending unit is at the front of the block on the drivers side.

 

Just remove the hose and fill it with distilled water until it come back out the same hose I just removed? Just want to be clear on what you meant?

I thought about ordering a OEM thermostat and just changing it with my flush, I read all your posts on the issues and the problem you had with the thermo, but I didn't do it. Will try the add water thing before I leave tomorrow, if it does it again I will get a new thermo on order. Order only so will take a day but that's fine, I can drive the F150 if it acts up.

 

The OEM thermo is the only one you can trust since they are more elaborate nowadays with the double valve and they are only a dollar or 2 more.

Remove the hose from the pass side front of the intake manifold, add water into the reservoir until it comes out of the vertical pipe, replace hose, fill to line. If you reservoir is already up to the line water (and hopefully air) should come out of the pipe when you remove the hose so just put it back on. You can do a partial drain to save your antifreeze when you change the thermo and if it still won't stay near the line you can have the cap checked at O'reilly's or maybe Autozone.

The new aftermarket thermo I had in it when it was limping or fail safing had a bottom valve that wasn't long enough to reach the bottom hole and it was opening at over 200* (new one!).

 

I know nothing about the V-10 and it's sensors.....

With that said, if she only drove 200 yards from the house and the engine wasn't warm yet, how can the thermostat cause the light to come on?
Is there a sensor that monitors coolant flow? What was the coolant temp?

I'm not being argumentive, just trying to learn something.

 

A hot spot will set it off.

 

The dash light indicates:

coolant TEMP to hot -AND/OR- Low OIL Pressure

Likely an open (or short) will fool the computer into thinking one or the other is at fault - in lieu of your recent work likely a false alarm.

 

Update, leave this morning - no light at startup - out of the hood - couple miles down the road, I'm thinking all good now - just a fluke random light or I was a little low after my flush......

2 miles into my drive - pop - red light on my dash. This time I can't stop immediately like I did the 1st time, I'm on a divided road, median in middle one lane on each side and I got to get to the next cross road. By the time I pull over about 300 yards later, she's almost pegged on the temperature gauge and I can feel it starting to chug, around that last corner. Actually kind of reminded me of when I blew the plug in my other EX - well minus the HUGE BOOM. Like it had a misfire. Shut it off just as she starts to puke coolant all over the place. Let it cool for a little bit (probably not as long as I should have) but I also brought a really long pair of channel locks for that reason. Stood back and opened it up, put some golves on then pulled the thermostat, - hooked it back up, topped with distilled water (which I brought with me, again just in case) and drove it back home. Which was a whole 2.7 miles away. Got the F150 - went to Oreilly - got a new Motorcraft Thermo - they did have it in stock.

Came back - installed it - topped it off with some 50/50 antifreeze and distilled water and off I went. Now an hour late.

Sorry no pics - was too rushed - but it did happen.

So Money-Pit to answer your question - apparently you can get your engine too hot in just a few hundred yards if your thermostat is bad, or at least hot enough somewhere to trip a light. Took a mile or two to start spewing fluid though. And no the temp gauge wasn't reading hot, barely off cold, but I shut the truck down within 10ft of the light coming on the 1st two times. I'm guessing the last two days it was sticking then working, sticking then working...... and that's why it didn't go into limp mode and actually over heat. Today it apparently decided it was done and it was only doing the "sticking" part.

But for now will call this one solved - unless it continues to give me issues.

BTW Brent - thank you! You were spot on

EDIT: what's bugging me though it what are the odds? I just flushed it two weeks ago, wonder if what I did caused a thermostat that was at the end of it's life anyway to fail. Just think the flush and what happened the last 2 days have to be related somehow.

 

Hey I said sticking thermostat before Brent...