Bought a '94 Explorer, a few small issues/questions

[JasonJ92]

Two days ago I bought a 1994 Ford Explorer Limited, 4WD 4.0L V6. I'm noticing a couple of things that make me a little nervous.

First, of course, the check engine light. It pulled code 551, IAC Circuit Failure.
I'm not sure what that is, does, or how to fix it. I'm not too bad at fixing things once I know what I'm fixing, but with this I'm kind of lost. I don't know what to look for or what to buy.

Second, it has a bit of ticking while it idles, and a knock when it starts. With the knock, it's literally as if it knocks twice as it's turning over. Every time. Two knocks right as it turns over. I'm not sure if that's something troublesome or just something it does. I've never had a Ford and I don't know how they work.

Third, the interior lights won't turn off. They turn off about an hour after I turn the car off/lock it. About an hour later I'll look outside or get in and realize the lights were off, then when I start it, the lights come back on and remain on for the entire time I'm driving and about an hour after I stop. I tried spraying the door latches with WD40 like I read on a few sites, but that didn't seem to help.

Any insight on any of these issues would be greatly appreciated

-JJ


Also, if there are any suggestions of things I should replace or other general maintenance to start off with (oil change, changing spark plugs, etc) I'd greatly appreciate that too. I'd like to get it in good running condition so I don't have to worry about it randomly breaking down on me for something I could've easily prevented in maintenance.

 

[Explorer0204]

How many miles? Depending on the mileage you should do some type of trans fluid change. If it is under 60k since the last full flush (doubt you would know) Then flush it again. If not I would personally do a half change. (drain fluid, drop pan, change filer, refill).

Other than that obviously oil and spark plugs are good.
Don't know on the code sorry but the knocking sound could be a cause of it ya never really know.

 

[FR-425]

The "Idle Air Control" valve (IAC) is this dude right here:

This would be your Problem on the 551 code.

This is the cause of the Predetonation on start up. And other performance issues. It's a MUST repair item!
You won't be able to do any other tune up trouble shooting until this is replaced.

Get the MotorCraft one: Worth the extra coin,
http://www.rockauto.com/catalog/x,carcode,1119631,parttype,6072

 

[FR-425]

Dome light:

You have a bad door switch: "Thinks" one door is still open..

To narrow it down.

Get in, all doors closed.

Use your fob or the door lock switch to lock the doors (turning off the lights)

Then open one door at a time.

Re-lock each time to override the timer.

You'll need a buddy to open the rear hatch for you.

If the light comes on that door switch is ok.

Note: It is most likely the drivers door (most use) and can be intermittent.
The wire bundle going to the door can fatigue over time causing intermittent open/short.

But if the problem is consistent and you have no other issues with locks, power windows, etc is is just the switch.

Oh the switch is just a push button switch in the front of the door jam. Easy fix.

 

[FR-425]

For general maintenance I highly recommend going with manufacturer specs on the engine oil.

5W-30 and only the best. I use Mobil 1 Full synthetic, and the Mobil 1 filter.

When I first got mine there was no telling what was in there.

So I "weened" it off the standard oil, starting with High detergent synthetic blend- to clean out the sludge...3 oil changes in 3,000 miles....

Then go to the full synth.

Oil now remains clean (yellow) for 3,000 miles between changes. Mobil 1 claims 5000 between changes but I'm a bit more conservative on 150,000+ mile engines.

Definitely get new fluid in the trans, and filter of course.

DO NOT TAKE IT TO JIFFY LUBE TO GET IT FLUSHED!

Flushing the a4ld can cause more problems than you care to know!

If you can find a good shop that filters the fluid both in and out and will take the time to flush the cooling system and the trans separate that is the way to go.

These transmissions are sensitive to contamination in the fluid, so if care is not taken when flushing it, it will be a nightmare.

For the rest: dump the diffs and the transfer.

Transfer case uses Mercon transmission fluid.

If your rear is Limited Slip use Royal Purple 75W-140 Limited Slip Synthetic. (synthetic is required for the 8.8 LS.)

 

[FR-425]

Ok, Well I need a nap now.

Welcome to the Exploration!

I love my 94' Limited! She's a keeper!

 

[JasonJ92]

IAC Valve part: what exactly goes wrong when that goes out? It runs a little rough but I've had cars run worse. I guess I'm almost wondering how much better it'll run when I change it.

The knocking: Is it likely that its in relation to the IAC valve?

Dome lights: still no luck with that so far. Today for a minute when I locked it by the fob it actually turned off but after I started it to leave work tonight it went back to the light staying on. Locking it by the fob also does not turn it off.

General maintenance: so from what I understand, do the IAC valve first, oil change, transmission fluid change, new spark plugs. I'm assuming I should probably go to an oil can Henry's or something to have the tune up stuff done.

Any other things to worry about or get done ASAP?

Thanks for the insight so far. I really want this car to run nicely and last me a good while.
Oh and it has 169k miles on it.

 

[FR-425]

As I said the IAC is a must replace.

Your just lucky right now that it doesn't keep stalling at idle. But soon it will.

Again, as I already said.

The predetonation (knocking) is related to the IAC.

With the IAC out you won't pass emissions either.

OIL CAN HENRY's??? Just sounds disreputable.

Think that's the sort of place I mention by another name (jiffy lube)

 

[Explorer0204]

For general maintenance I highly recommend going with manufacturer specs on the engine oil.

5W-30 and only the best. I use Mobil 1 Full synthetic, and the Mobil 1 filter.

When I first got mine there was no telling what was in there.

So I "weened" it off the standard oil, starting with High detergent synthetic blend- to clean out the sludge...3 oil changes in 3,000 miles....

Then go to the full synth.

Oil now remains clean (yellow) for 3,000 miles between changes. Mobil 1 claims 5000 between changes but I'm a bit more conservative on 150,000+ mile engines.

Definitely get new fluid in the trans, and filter of course.

DO NOT TAKE IT TO JIFFY LUBE TO GET IT FLUSHED!

Flushing the a4ld can cause more problems than you care to know!

If you can find a good shop that filters the fluid both in and out and will take the time to flush the cooling system and the trans separate that is the way to go.

These transmissions are sensitive to contamination in the fluid, so if care is not taken when flushing it, it will be a nightmare.

For the rest: dump the diffs and the transfer.

Transfer case uses Mercon transmission fluid.

If your rear is Limited Slip use Royal Purple 75W-140 Limited Slip Synthetic. (synthetic is required for the 8.8 LS.)

Good call forgot to mention the diffs and trans case.

I am by no means a dealer person when it comes to.. Well.. Anything. That being said I had them flush my trans. I just couldn't trust anyone else. It was way too expensive. 200 some bucks bit they did a good job and it runs great so I'm not complaining. From now on I may do full flushes every 30k or pan drops every 15k not sure yet. These transmissions last a lot longer on good fluid. I love when someone is like
"The transmission in that thing is **** it broke at only - - - miles" then I ask when is the last time you changed the fluid. That blank stare tells it all. Nothing is foolproof but take care of the vehicle and it will take care of you. Good on the op for being one of the few people who does.

 

[FR-425]

Good call forgot to mention the diffs and trans case.

I am by no means a dealer person when it comes to.. Well.. Anything. That being said I had them flush my trans. I just couldn't trust anyone else. It was way too expensive. 200 some bucks bit they did a good job and it runs great so I'm not complaining. From now on I may do full flushes every 30k or pan drops every 15k not sure yet. These transmissions last a lot longer on good fluid. I love when someone is like
"The transmission in that thing is **** it broke at only - - - miles" then I ask when is the last time you changed the fluid. That blank stare tells it all. Nothing is foolproof but take care of the vehicle and it will take care of you. Good on the op for being one of the few people who does.

Amen!

 

[FR-425]

$200 sounds cheap did they only flush the trans?

That would be really cheap if they did anything else.

But high for just a flush. But money well spent in the long run.

 

[Explorer0204]

Woops. Double post

 

[Explorer0204]

$200 sounds cheap did they only flush the trans?

That would be really cheap if they did anything else.

But high for just a flush. But money well spent in the long run.

Just a flush. No filter. So Yea it is high but again I didn't know who else to trust so I just sucked it up and did it. My local amco does full flushes for 140 but I have had a bad experience with them in the past so I just preferred to not risk it over 60 bucks. I specifically did NOT do the filter because my trans had 54k miles on it. That is a pretty high amount of miles to a a full flush and filter change. I didn't want to shock the Trans too much by hitting it with so many changes at once. It was recommended to me to do just the flush then, in 15k a pan drop and filter change or a filter and flush in 30k.

I take good care of my ex but I do work her pretty hard towing Sometimes and hauling, driving in the winter, off road.. Etc. I would rather invest a little money in the Trans to keep it in good shape as long as possible rather than having to buy a new one at 1400 bucks after the core charge for a remanufactured one

 

[JasonJ92]

Good news, changed the IAC valve yesterday and it seems to be running smoother and the check engine light has stopped showing its ugly face. it's still doing that double knock though. :/

 

[Aeromax]

It's good you changed the IAC. I had the same problem with it threatening to stall the engine LOL. Changed it and it runs soo much better... As for the knocking you're hearing, hmm... Can you upload a video?

 

[Explorer0204]

It's good you changed the IAC. I had the same problem with it threatening to stall the engine LOL. Changed it and it runs soo much better... As for the knocking you're hearing, hmm... Can you upload a video?

I think we need a video for this one for sure.

 

[JasonJ92]

Didn't even think about a video, I'll do that tomorrow. Thanks guys, stay tuned

 

[FR-425]