Whinning noise when idling for a while.

[Mkrucejr]

The last couple days, I noticed when my X was idling for a while (5-10mins) after running for a while, there is a whinning noise coming from the engine. It sounds like the passenger side somewhere. When I hit my gas, it goes away. But when the RPM's come back down, it comes back. Once I start driving, it's gone for good. Any Ideas??

 

[xdviper]

I also have the same problem with my 97, when the weather is over 85*F, and I've been driving for about 5-10mins, mine will come on also. I've gotten it checked at numerous places, and they told me nothing is wrong with it.
In the winter, you won't hear it, but when the summers heat comes along, you'll hear it... :exp:

 

[Turdle]

http://www.explorerforum.com/forums/showthread.php?t=161590&highlight=chirp+squeak

 

[Mkrucejr]

Well, I heard the noise again today, I finally had a chance to pop the hood to hear it....It's NOT the belt....Almost sounds like "air" moving. I want to say its coming from the middle of the engine somewhere. I can't pin point it. When i step on the gas it stops. when i let go it comes back.....once i start driving, it stops.....I wonder if its heat related, b/c it was extremly hot today, and it was just at idle when it started.

 

[xdviper]

Well, I heard the noise again today, I finally had a chance to pop the hood to hear it....It's NOT the belt....Almost sounds like "air" moving. I want to say its coming from the middle of the engine somewhere. I can't pin point it. When i step on the gas it stops. when i let go it comes back.....once i start driving, it stops.....I wonder if its heat related, b/c it was extremly hot today, and it was just at idle when it started.

exactly what i said, when the weather is above 85*F, you'll hear that sound and when you drive off it will stop but at red lights or idle it will come back on. it happens on my explorer and my friends 96 explorer also. i've gotten it checked out at 6 mechanics and they told me theres nothing wrong with the engine.

 

[cybergasm]

Could always try to remove the black cap on the IAC valve and see if that helps too.

 

[manaen]

Could always try to remove the black cap on the IAC valve and see if that helps too.

I'll second that

I had that exact problem on a previous engine, I removed the cap and cleaned out the dirt. Eventually it came back so I just replaced the IAC.

 

[xdviper]

i'll try that out today
damn its 98*F today, it'll be easy to fix and dianagonise.

 

[xdviper]

Today while driving around town, temperature around 102*F I started hearing the sound again so I had the chance to record it on my phone.... Sorry about the mute video, there was too much background noise so I muted the video...

Check it out
http://www.youtube.com/watch?v=2YpvZGcJD74

 

[manaen]

the IAC is on the driver side of the upper intake on the 4.0 OHV motor it is a small cylinder that mounts with two bolts, it has a plug with 2 wires that connect to it, and if you take it off it has 2 small holes in it with a solenoid controlled valve on the inside. there is a small cap (black plastic on OEM, however the newer ones have a metal cap) that has a small filter under it that covers an air bleed hole. For some reason when it gets old / dirty it makes a whining noise. The whole assembly is about $25 if I remember right..

Sometimes if you push on the cap while it is whining it will stop, I removed the cap with a screw driver (just pop it off). it will more than likely stop making noise, if that is the problem. You should be able to feel a vibration coming from it that matches the harmonics of the noise it makes, like a high frequency hum.

Good luck these things can be tough to find sometimes.

 

[manaen]

Oh, also it is a good practice to clean out the valve portion of the IAC with some carb cleaner, and check to make sure that it moves freely

 

[xdviper]

manaen, thanks for the tip, i'll check it out and maybe make it the next project, but on mine i hear it coming from the air filter place just as seen in the video. it was had a slight vibration. maybe that has something to do with it also. anyway i'll also go ahead and get one of those compressed air cans and air inside the pipe of the air filter place. heh, i'm not too car/engine savvy so just bear with me while i give them names.

 

[manaen]

Well it can be deceptive since the IAC is on the top of the intake next to the throttle body, which would resonate out through the intake into the air box. If you hear it again just check the IAC to see if the noise is actually coming from that. Be careful with the compressed air around the MASS too much pressure could potentially cause damage to the MASS. They are best cleaned with carb cleaner that is safe for O2 sensors (It will say it on the can).

I'm still betting on the IAC being the culprit, mine started out on hot days and eventually it got worse to the point it did it all the time no matter what the temperature was.

 

[Vinniety]

I dont know about a 1997 explorer but i had a same problem with my 99 mazda 4.0 OHV and it was a whinning noise coming from the intake which ended up being the MAFS (mass air flow sensor). Not sure if you have one on your 97 and sorry if this doesnt help but i would recommend to look at that. I cleaned it and it never made the noise again.

Good luck and keep us posted.

 

[Mkrucejr]

I THINK the "air filter place" is where i think I pin pointed my noise too, but since i havent heard it since that day, can't single it out. Thanks for the tips

 

[fleettech225]

I've got a stock '99 X w/4.0 ohv, and mine was doing it also. I read here a few weeks back it was the idle air control solenoid. I replaced mine w/new, and the noise stopped. hope this helps!!

________________________

'99 stock explorer 4.0 ohv
110,000

 

[Mkrucejr]

well i heard it today. of course i was in a rush. but i popped the hood. where the air filter is (all the way on the left), looking at it from the front of the truck, behind it, has a small plug thing, with a rubber gasket (i think) and a couple wires coming out of it. when i pushed on it, it changed the sound of the noise, so i am guessing its got something to do with it. anyone fill me in on what that is?

 

[Vinniety]

well i heard it today. of course i was in a rush. but i popped the hood. where the air filter is (all the way on the left), looking at it from the front of the truck, behind it, has a small plug thing, with a rubber gasket (i think) and a couple wires coming out of it. when i pushed on it, it changed the sound of the noise, so i am guessing its got something to do with it. anyone fill me in on what that is?

Take a picture it will make it alot easier to tell you what the part is.

 

[Raulsk8]

Hello to all members, first post so be gentle.... I just bougth a explorer 96 XLT 4.0 OHV and right away i noticed this whinning noise... being annoyed by it i noticed that (at least in my case) the sound is produced from the vibrations that are produced by the air being sucked in by the engine, the culprate (again in my case) is the housing where the MAF sensor goes. It does not assemble as thight as it should to prevent this sound... I have not been able to come up with a solution to it, but at least we now know what the problem is. Hope it's the same case for all....

 

[manaen]

if it is part of the housing for the MAFS, you could use black silicon to stop any vibrations. Take a picture of the item and post it so we can get a better idea what part you are talking about.

Oh, and welcome to the board, you will find a wealth of knowledgeable people here who genuinely want to help. Despite what J**P says, it's an explorer thing