Explorer shuts off out of no where....(weird)

ok guys i have a weird issue that ive never experienced in any vehicle

what im working with is a 2003 4x4 w/the 4.6 V8

when its cold out(well its 38 degrees today thats cold for orlando) after the explorer warms up after about 10 minutes of driving and i have the heat on it will just cut off.

now it only happens when stopped, either parked or at a stop light. when it happens i can throw it back in park and turn it right back on and it starts right up. or if its parked i just turn the ignition of then right back on and it starts right up either way.

it has only happened to me when the heater is running but my wife has said it happened to her just when it was cold and the heat was off.

does anyone have any idea why this might happen? im not so concerned right now, unless you fellas give me any insight as to why i might need to be, because it starts right back up every time.

so help me out guys if you have any ideas

thanks


MODS - feel free to move this, i just wanted it where guys with 2003's will see it - thx

most Ford vehicles have a fail safe system. ie. headlights start flashing or it shuts itself down. usually it is a failing circuit or a short in the wiring.

zukman said:

most Ford vehicles have a fail safe system. ie. headlights start flashing or it shuts itself down. usually it is a failing circuit or a short in the wiring.

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great.... so i have a short somewhere.

How are your battery terminals? That would be the first thing I would check

macknos94 said:

How are your battery terminals? That would be the first thing I would check

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they are clean and tight. and the battery is only 1 year old.

nice truck BTW

also the only mod is K&N cold air intake and remote start. i dont think that would have anything to do with it though

Your 03 has FMEM. You should get a wrench light and some codes thrown if its' the system.

Taking a complete stab at the dark here, it *almost* sounds like the vehicle heats up to a point that a sensor somewhere changes state, and that causes the stall condition.

That is a weird thing though, never heard it, and I listen a lot to 02-05 issues.

Go get codes pulled, but I'd be careful driving it, that would suck to stall in a curve.

.... which reminds me. I had a P71 crown vic that did the same thing. You'd be at 95, get in a curve (hence my warning), and it would die. But it was hard to start. Turned out crap in the gas tank was sloshing and choked the car out. another piece to think about - an abrupt drop in fuel pressure could do that w/o a code or warning.

Shawn

shawn,

thanks for the info. it seems to only do it when in an idle state. regardless, i have been very careful while driving it. we are a one car family so my options are limited.

What is an FMEM - and i get no wrench light. it just says "check charging system" once it cuts off

but as far as the heating up thing, it never does it in the summer even when its 100+ degrees and the AC is cranked as high as it can go. only on cold days and when the heat is running?!?

i think i will run by autozone and try and see if i can get the codes. and i am def going to take it to my mechanic on monday morning. hes a great guy and the thing is still under warranty so i might as well.

i will post results here when i get it to the shop in case anyone else has this issue.

You might want to have advanced auto test your alternator. If its starting to go out stalling can happen. It may not be pushing enough amps so when you heat radio plus your other stuff used to run the vehicle could be pulling more then the alt can handle

macknos94 said:

You might want to have advanced auto test your alternator. If its starting to go out stalling can happen. It may not be pushing enough amps so when you heat radio plus your other stuff used to run the vehicle could be pulling more then the alt can handle

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you know you might be the winner here.

i noticed a bit of a squeal a couple weeks ago. listened under the hood and came to the conclusion it was most likely the alternator or alternator pulley.

i will go have that checked also. thanks for the help.

you know what though, now that i think about it.

i remember this explorer doing this the day after i bought it in NC when it was snowing i had the heat on and was sitting in a parking lot and it just shut off. it only had 19k miles on it then.

that probably would make it something other than the alternator.... right?

After I put in my hi output alt. In I never had any issue. Mine shut off a hand full of times hut now its not an issue. Have them check it out hey its free so worth a shot

macknos94 said:

After I put in my hi output alt. In I never had any issue. Mine shut off a hand full of times hut now its not an issue. Have them check it out hey its free so worth a shot

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oh yea i def am going to get that checked out. i was just spit ballin why i thought there was a chance it might not be that.

if it is the alt. then i am definitely going with a high output replacement.

where did you get your high output alternator. they dont seem to sell them at the local autozone

so i got my alternator and battery tested at auto zone and there are no issues. both are good.

the guy said he had never heard of anything like that before. b/c it doesnt sputter or anything before it cuts out. its just like someone has flipped a switch and it turns off.

any other ideas???

bump for advice, help, any kind of lead .......

FMEM= failure mode engine management. Your vehicle is totally run by a computer. It even has a local area network, no **** (google CANbus).

Without codes, it is hard to help you.

I am a little surprised that the switch wasn't the issue, or the battery. If the batt is low when the idle drops, the switch cuts from alt to batt, and the batt can't take it and the vehicle stalls.

I would also check fuel, that's something that can kill the car without setting codes.

Best thing to do is to get a in flight recorder. Some places rent them. You can see *exactly* what was going on when it died.

You could also have an intermittently failing PCM.

Dunno, what you have doesn't appear to be too common; I try to keep up with common failure modes on the 02-05 series...

Shawn

so i wrote an email to the "magic mechanic" i know i know. well this guy has a sat afternoon radio show and is pretty on point and has a good rep.

this is what he said:

If the check engine light isn't on I would suspect low minimum idle air flow like a restricted idle air control or restricted throttle body, Let us know if you want us to take a look at it, 407-629-2661
Larry

so its not getting enough air at idle? how could that be with the K&N and if so why only when the heat is on????

huh

yeah, if its' getting choked out, then it could. If the vehicles MAF can't understand the new filter, it may be calibrated to flow so many CFM at certain butterfly positions, but the new filter could be dirty or clogged, and its' not providing it.

The heat issue - your PCM is right next door to the plenum. This *could* be a short that happens when the PCM box gets hot. There are a LOT of flaky brains in the 02-05 series, and heat tolerance is an issue, regardless of what the official line is.

You could try starting the vehicle, letting it warm up, then hitting the pcm with a hair dryer and see what happens? (shrugs)

Shawn

i experience the same thing in a 2003 explorer 4.0. K&N intake. with my heater on and vehicle stopped, mine sputters a bit before shutting off. its also easy to crank right back up. turning the heater off makes the idle return to normal. My guess was low on freon and compressor on and off was causing it.

Does your engine idle smooth?
Mine did this one time when I first bought it with 68k miles. I ran two 12 oz bottles of chevron techron and it has not done it since. This week Advance auto in our home area has buy one get one free.I do not run ethanol gas. Today ethanol gas today has detergents to prevent the varnished injectors. Years ago ethanol gas would cause idle problems after a few years of running it. I don't hear about these idle problems much anymore. I did read on here about someone installing a K&N and having idle problems.
Sorry I can't help you more.

i'm wondering if has something to do with the throttle position sensor? now that i think about it if that was bad or off then it could cause the engine to shut down correct?