Engine Stalling Problem

[Flashover]

So today I used my A/C for the first time in probably a year or so (I always use the regular blower, never had a problem). I was driving up a little hill, accelerated at the bottom to get up and about half way up I let off the gas because of the stop sign. Before my brakes finished stopping my car the engine stalled out and stopped me. There was a little red battery icon that went on in the dash. I got the car to start up again by tuning off the A/C and car lights.

I finally got home and I experimented with the blower/A/C for a little. Whenever I turn on the blower (or A/C) the headlights would dim a little then come back on. Also now whenever I choose a setting the blower sounds like it's pushing the air out forcibly for about 5 seconds then works as normal but the RPMs seem like it's acting wierd (jumping around and going really low). Then when I turn it off there's a clicking noise that sounds like it's from the passenger side.

I have a 1998 Explorer Sport, V6 SOHC, Automatic Transmission (I can provide any other information that's necessary).

Can anyone help me out? Thanks.

 

[rickybobby]

i would recomend getting the alternator tested

 

[Flashover]

The whole alternator system was replaced about a 1.5 years ago so it's pretty new.

I remember a mechanic told me once (not sure if I remember correctly) that the RPMs lower because there's this little red disc on the engine that takes a little load off the engine when the blower's going and causes the jumps in RPMs. I'm thinking it's more of an engine problem.

I don't really know too much about cars but I'm just speaking my mind to see if a "diagnosis" can be found...

 

[rickybobby]

there is nothing that takes load off the engine. the rpms go up to compensate for the extra load. the alternator only being 1.5 years old doesnt always mean anything, i have seen a couple bad out of the box

 

[techieman33]

Maybe he meant it put more load on the engine when the ac compressor clutch engaged?

 

[rickybobby]

could be

 

[rickybobby]

it could also be the iac, idle air controller

 

[jlsparky7]

IAC sounds like the problem.

 

[Flashover]

On my engine (not sure if it's the same on everyone else's) there's a small red disc thing that is on a belt. If you stand infront of your car with your hood open it's a little to the right of the center. The disc spins about every 45 seconds or so for a few seconds, stops, and repeats. When that disc spins the RPMs start to jump (not dramatically, maybe about 500 RPMs up/down).

I think I'll check the IAC first since it seems like a simple job. I found this article (http://www.explorerforum.com/forums/showthread.php?t=84220) but would any of you happen to know where the IAC is located in a V6 SOHC engine? Can't find it in the manual...

 

[techieman33]

I can't think of any red discs, but i'm not super familiar with all the workings of a sohc. The IAC is near the throttle body. If you start your way at the air filter box and work your way down that tube you'll run into it.

 

[rickybobby]

i think he's referring to the copressor clutch engaging and disengaging. there are a lot of threads on here for cleaning and replacing the iac

 

[techieman33]

i think he's referring to the copressor clutch engaging and disengaging. there are a lot of threads on here for cleaning and replacing the iac

Yeah it has to be the clutch, the red disc part has me confused though. I guess someone could have painted it or something.

 

[rickybobby]

can you post a pic of the red disc thing?

 

[Flashover]

It's 3am here so I'll post the picture up in the morning and check the IAC at the same time.

 

[Flashover]

Here're 3 pictures for the red disc:

I looked for the IAC but can't seem to find it...

 

[rickybobby]

The red disc is the compressor, and the iac is under the cover thats says 4.0 sohc

 

[Flashover]

I see 4 bolts on it and it looks like the cover will pop off easily. Is the cover just a plain cover or is it one of those "important" parts and is there anything I should know before taking it off?

 

[rickybobby]

I beleive its just a plain cover. iirc ive seen a couple driving around without it

 

[Flashover]

I believe the ones without a cover are the OHV version, either the V6 or V8. I'll try taking it off and see what I get, thanks for the help by the way.

 

[Pontisteve]

LOL> The AC compressor clutch is black. It's only red on your truck because you've run straight water in the cooling system in the past, and it's spilled over onto the clutch, staining it with rust. Be very sure your cooling system now has coolant/water mix in it, and not straight water. That will lead to some serious problems over time that you don't want.

When the AC compressor engages, it drags the motor down because of the extra load/strain it puts on the engine. The engine computer senses this load and raises the rpms up a little to compensate for it. To you, this should feel pretty much seemless. At most, you might notice a quick dip in rpm when the compressor clutch engages, and then the rpm should be right back to normal.

Your problem sounds to me like it could be just a battery going bad. You'll figure that out pretty quick if I'm right. But the symptoms are dim headlights, hard or no starting, a clicking noise when you try to start your car (instead of an engine starting noise), and everything electrical that you turn on will make the situation worse.

The alternator could be bad (despite being only 1 year old). Generally speaking, if it runs just fine when it does run, but then won't restart, it's the battery. If it has all the battery issues of no starting, plus a poorly running engine, dim headlights, etc then it's more likely your alternator.

For what its worth, most aftermarket alternators are junk compared to the factory one. The fact that you replaced it and it's bad again seems almost likely if you didn't buy a factory alternator last time.