[darsky]

I have had an intermittent problem for some time that has recently become quite regular. I will hear a moan (either while driving or idling) that starts quiet and gets louder. If I let it run its course, the engine will smoothly/calmly stall. Then I can start it up again right away with no hesitation and it runs fine.

If I give it some throttle rather than letting it run its course, it will not stall and the sound stops with the engine still running well.

I have cleaned the MAF sensor and air filter (K&N). But that did not help.

I have not found this exact behavior discussed anywhere online. Any idea what might be causing it?

Thanks for any help.


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[VIC-TIM]

can you get an audio/video of it?

 

[golf4283]

my guess is fuel pump.

 

[Ezekial]

$10 says it's the IAC (Idle Air Controller)


Mine recently sounded like a fog horn. Mostly happened at cold temps / cold starts. A blip of the throttle normally solved it for that driving session.

If you search Google, there are lots of hits actually lol
https://www.google.com/webhp?sourceid=chrome-instant&ion=1&espv=2&ie=UTF-8#q=fog horn mustang

 

[sganow]

I was thinking IAC also.

 

[darsky]

$10 says it's the IAC (Idle Air Controller)

Mine recently sounded like a fog horn. Mostly happened at cold temps / cold starts. A blip of the throttle normally solved it for that driving session.

That really sounds like my problem. On another forum, someone called it an IAC "Hoot". So I cleaned the IAC yesterday. It was so dirty inside, I couldn't remove all the grime. It seemed better for a little bit. But last night it got worse.

I am definitely going to replace the IAC right away and report back here.

 

[VIC-TIM]

why I was asking about hearing it. IAC's I have heard were more of a growl than a moan.

 

[Ezekial]

This is the IAC I bought. The plug is in a different location than factory, but fits fine: Amazon.com: Motorcraft CX1808 Idle Air Control Motor: Automotive

This one I think is the same part, but the plug in (possibly) the OE location: http://www.amazon.com/Motorcraft-CX1917-Idle-Control-Motor/dp/B000C5HI30/

Either one should work fine to my knowledge.


I also grabbed a new gasket: http://www.amazon.com/Motorcraft-CG758-Gasket/dp/B00130J34K/

 

[darsky]

why I was asking about hearing it. IAC's I have heard were more of a growl than a moan.

I tried recording the sound. But it is only happening randomly while driving. So I have not had any success.

 

[darsky]

This is the IAC I bought. The plug is in a different location than factory, but fits fine: Amazon.com: Motorcraft CX1808 Idle Air Control Motor: Automotive

Thanks. I happened to buy the same unit from Amazon this morning. It should arrive tomorrow.

I do know that the position of the plug differs between the GT and the Bullitt. My car is a Bullitt but the unit on it is for GT (with plug facing up). I replaced it myself a few years ago. The new one is specifically for the Bullitt. I had noticed the position pointing up results in the plug wire being stretched tight. That can't be good. So the correct replacement will be better in that regard.

As for the gasket, I didn't order one. But I will probably just make my own. It is a simple enough gasket.

 

[Ezekial]

Thanks. I happened to buy the same unit from Amazon this morning. It should arrive tomorrow.

I do know that the position of the plug differs between the GT and the Bullitt. My car is a Bullitt but the unit on it is for GT (with plug facing up). I replaced it myself a few years ago. The new one is specifically for the Bullitt. I had noticed the position pointing up results in the plug wire being stretched tight. That can't be good. So the correct replacement will be better in that regard.

As for the gasket, I didn't order one. But I will probably just make my own. It is a simple enough gasket.

Cool

The original gasket may very well be fine. I just grabbed both at the same time

 

[dancad]

Curious as to how many miles were on the car when this started to happen and has anyone been able to clean and replace ? After you did clean it, did you disconnect the battery to allow the computer to clear before restarting ?

 

[VIC-TIM]

cleaned and replaced mine on two different cars. no need to disconnect the battery. worked fine afterward.

 

[Warlock]

$10 says it's the IAC (Idle Air Controller)
Mine recently sounded like a fog horn. Mostly happened at cold temps / cold starts. A blip of the throttle normally solved it for that driving session.



Had the same sound. Did it 3 times between 47K and about 54K. Nothing in the last 3K. Now if I fix that small a/c leak.

 

[sganow]

When mine was acting up I tried cleaning it but it didn't do much good. I replaced it and it has been fine since.

 

[darsky]

Hi, everyone.

Thanks for all the responses to my question. I am back with a final update.

To answer dancad about miles on my car when this started happening... It is at 218k now. I think this actually started back around 180k. But it was so infrequent, it didn't concern me enough to deal with it. It only started happening more often within the last 1000 miles. And it became a sure thing within the week when I posted my question. I had removed and cleaned it with the battery disconnected. But that only brought on all the bad IAC symptoms that I wasn't experiencing before. But that was fine by me. I felt more confident in replacing it.

RESOLUTION: I ordered a new IAC (the one meant for the Bullitt, not the GT) from Amazon on Friday with guaranteed delivery on Saturday. It arrived before noon on Saturday and I swapped it out. I also disconnected the battery while doing this. So all bases were covered. It has been running perfectly since.

There are definite differences between the GT and the Bullitt IAC valves. So, while the GT will work on a Bullitt, I suggest making sure to get the correct item for your Bullitt (Motorcraft CX1808 Idle Air Control Motor) when replacing an IAC unit.

 

[sganow]

Glad you got it resolved and that it was an easy fix.