How to: IAC valve cleaning thread (w/pics)

[FNFAL]

This thread fixed my problem, thanks!

99 sport with 4.0 SOHC, ran fine till today, got very cold last night, first real cold of the season. Ex would start right up but would not idle without dieing, have to keep at least a light touch on the accelerator or it would die. Even after it was well warmed up by being driven for 5 miles it would die. Cleaned the IAC valve and it runs fine now.

The plunger or disc thing was stuck closed on mine, I let it soak in electric contact cleaner for 10 minutes and then forced it open with a qtip. It was stuck tight.

 

[W3HOG]

01 Sport trac start and idle prob, esp when wet out

I've read most of the posts here an I apologize for my slowness here. My 01 Exp Sport Trac seems to have a problem staying started, especially after a good rain. I can keep it running by gassing it, but it takes quite some time until I can come to a stop or even take my foot off the gas for turns, for it to stay running. I'm just wondering if this seems to be the simple IAC unit and wether I should just try removing and cleaning it or just buy and replace.
One other ? is how do I know what model # to purchase if I need to replace? Is it Standard or do I need to remove it and try to find numbers on the IAC unit itself? I just replaced the trans, so I'm not giving up on this truck yet!!
Thnax in advance for your answers and understanding! I really appreciate this site and the people on this!!
DAN

 

[cwall32]

I am trying to get someone to tell me how to get to my IAC. Can anyone help

 

[TANSTAAFL]

I am trying to get someone to tell me how to get to my IAC. Can anyone help

I have a 98 Explorer, it is located (AKA hidden) under the plastic cover (four retaining screws) on top of engine at front.

 

[sjdurb]

Accidently sprayed WD40 into IAC, immediately realized i was holding the wrong can and grabbed the CRC Elec. cleaner and blasted it all out... Think it did any damage?

 

[BrooklynBay]

It didn't do any damage.

 

[sjdurb]

Thanks... I felt like a doofus.

 

[AwwPhooey]

Awesome Post! Fixed the issue

Boy, day after Christmas and all of a sudden my ride won't idle- soon as I get off the pedal, dead... All I can think at the time is, crap, I just spent all my money on Christmas for the family, this flippin' really figures, you know? First thing that comes to mind is, fuel pump, and since I'm not experienced enough to do that myself, second thing that comes to mind is, don't have the 600.00 + to pay for the shop put one in, how am I going to get to work???

Came to this thread from online, read the blow by blow, took a deep breath and dug in. Found the IAC, right under the plastic manifold cover, took it off and found it to be really really dirty, with the plunger thingy all stuck. Grabbed a can of parts cleaner (cost 5.99), squirted liberally, cleaned with paper towel and Q-tips, let sit for 5 hours, and put it back in around 11pm.

WUUHHAAAMO- baby started right up and idled GREAT! Runs better than it has in years- man I never thought it'd be this easy, epecially with the lack of experience I have.

So THANK you to the person who posted this 7 years ago, and to all of you for the great advice! You saved me from a quick depression!

Phoo

 

[AwwPhooey]

One thing I noticed

On the pictures shown, his IAC has what looks like a black cap on the top of the unit- I believe some of you said this was removable, and contained some small filter.

My IAC was solid body one piece, no cap. What's the different between the two?

Phoo

 

[RupertExplore]

I think the black cap is for OHV engines, and the no-cap is for SOHC engines. I could be wrong. I got a replacement IAC valve (Delco, IIRC) that did not have the black cap, and it didn't fit on my OHV because the opening was a different shape than the one on the intake.

 

[gravy]

Sorry I'm not that smart when it comes to mechanics but... what is that thing under the IAC called. It has 2 tubes leading down somewhere in the engine and has an electrical socket aswell?

I believe that is called an EGR Transducer...hope that helps someone

 

[Carlos99]

Thanks !!

My '94 Explorer wouldn't start and I had all of these symptoms. Everyone I talked to said it sounded like everything but the IAC valve which was exactly what it was. After a good spraying with cleaner and multiple q-tips (it was filthy) my truck started on the first hit without ever even touching the accelerator. I'm not much of a mechanic but this thread really saved me money. I appreciate you guys for posting this information!
I'm not knowledgeable enough to ever start a thread, but I will definitely be back!

 

[sjdurb]

Hmm, I cleaned my IAC twice, and started getting that Moosecall only -after- I cleaned it. So I bought a new IAC valve and i'm getting the same moosecall, only a little bit lighter? Anyone got any ideas?

 

[baez23]

This has been soooo helpful for someone who has no mekanikul skillz.

But seriously, thanks for this writeup.

1996 Explorer Sport 2WD 4.0

For anyone who could use this info about symptoms and fixes -

Problem -
* The moose call in temps above 98 (I'm in the desert)
* Uneven idle. Not too violent but just a gentle change in rpm every so often, as if someone is randomly turning on the AC on, then turning it off.
* Recently a slight, ever so slight 'jerk' I'd sense (not hear or see on OEM rpm gauge) at around 37-42-ish mph. I have THE WORST shocks in the world (163K, same set in there. Guess what my next project is?) so I wasn't sure if I was feeling every bump in the road because of my soft shocks or if it was some sort of mixture problem.

What I tried
* For the Moose call
- replaced old radiator fan assmbly thinking it's the fan clutch making the sound.

RESULT - It wasn't.

* For the idle jumping and ever so subtle jerking
- Brake cleaned the MAF sensor.
RESULT - 50% reduction in idle jumping.

- Brake cleaned IAC valve by throttle body.
- Popped off that stupid black cap (which I hear is the culprit) to find no velvet 'filters' in it. Kinda cracked it while trying to pop it off. We can guess our RESULT.

RESULT - Engine wouldn't stay running for more than 3 seconds.

- Bought new IAC valve at store.
RESULT - Even more reduction in idle jump. Now the jump cycle is more frequent, but less prounounced. Engine runs sooo much smoother now.

CONCLUSION - Clean/buy new MAF sensor and IAC valve. DON'T break that dang black cap off. (With needle nose, pull straight up, mmm'kay?)


THE PLAN (feel free to comment on it)
Will start doing the carb cleaner spray tests around the vac tubes (PCV hose has no holes, from what I can tell), may check O2 and IAT sensors.

 

[SoNic67]

I did try to clean that stupid IAC valve too, but till I didn't replace it with a new one didn't solve the problem.

Is the AC "ON" while you feel those "jump cycles"? It might be from there.

 

[aatomicdawg36]

Iac valve gasket missing??

Hmm, I cleaned my IAC twice, and started getting that Moosecall only -after- I cleaned it. So I bought a new IAC valve and i'm getting the same moosecall, only a little bit lighter? Anyone got any ideas?

Question, when you first removed the IAC, do you remember or not if you had a gasket on there? I have a 2002 4.0L, and I took mine off this morning, cleaned it and replaced everything. I did it because of the rough idling in the morning, in the rain, in the cold, in the heat, well, you get the picture. Now, it SEEMS to run better, but I am just NOW starting to hear that whining sound everyone else has been complaining about too. So, long story short, I'm wondering if that's because I since I cleaned everything, and I didn't have a gasket on there to begin with, that maybe that's why I'm getting the whinning sound? Does anyone else know how IMPORTANT it is to have that gasket on there ??? I never seemed to have had one to begin with.

 

[soltero]

Had the humming noise for a few weeks on my '96 explorer, then I recalled having the same problem a few years back and how the noise went away by replacing the IAC VALVE (had to, since I messed up cleaning it). This time I didn't even tried cleaning it, I just went ahead an bought a replacement, the noise went away instantly an car ran a lot more smoother. However, the noise is back after a week, only this time is a very mild humming noise. I know it comes from he IAC valve, but I don't know why. Any Ideas?

 

[javari78]

Changed IAC, check engine light still on

I have a 2000 Ford Explorer Sport and I changed my IAC valve last week because the check engine light was on and the test at Autozone said that was the problem. So I replaced it and my check engine light went off for a couple days but has now come back on. I went back up to Autozone and found that the light is on for the same reason.

Could it be something other than the IAC valve?

I noticed a pipe that appears to be open when the engine is off

but when the engine is on the pipe tightens up and looks closed

Could this pipe or whatever it's connected to be the problem?

 

[That911guy]

great thread, and great how-to. now that its cold my car is idling so low its stalling, and the humming is defeinatly present, i just got the explorer a week ago and didnt know if that loud humming was something id have to get used to.

just ran the part through the autozone website and its $43. so i may go pick one up today. i dont think i can keep my 9 month old daughter entertained long enough to clean it (single dad).

 

[jcquads]

Where is the IAC Valve located on a 04 Ford Explorer XLT 4.0 . I just must be blind.Any help would be greatful.