Whistle Noise Under Hood While Accelerating

[BlackOut33]

Hey Guys,

My 2003 Explorer 4.6L V8

Last 3-4weeks ive been noticing if the vehicle is warm or cold I find when I accelerate with my explorer mind you I do have a K&N air filter in the air box which is clean I checked that I get a whistle noise.

I checked everything that I can really think of but I cant find any issue.

Never use to do it before but lately ive been hearing it especially if I have my windows rolled down.

Idle seems to be idling fine in park its @ 900 RPM and in Drive ruffly 800RPM

Doesnt seem like its stalling or anything but I thought I ask before I take it in to a pro and see what it is?

Any ideas would be greatly appreciated

 

[crazymind]

Is it a drop in or a cone type filter? With my k&n I get a whistel depending on throttle position but I know its the filter so it may just be that. Mine is a cone style but idk about the drop in kind it may be the same thing as well which is fine.

 

[OffTrac]

I have a drop in K&N and occasionally get the whistle too. Normal operation.

 

[BlackOut33]

Hey guys yeah my air filter is the drop in one I'm about to remove it
And put a regular air filter one of those fram tough guards and see if it makes a difference it's driving me nuts

It doesn't matter if the engine is cold or hot it whistles

 

[jp450]

My 05 does this too. It did it with the stock air filter and the drop in K&N. I do not think its the air box but more likely the throttle body. Mine does it, at least I notice it more, usualy when its cold but will occasionaly do it when hot.

 

[mall]

It's probably the idle air control valve http://www.explorerforum.com/forums/showthread.php?t=140213.

 

[BlackOut33]

Had the idle air control valve replaced last August 2012
Not sure what it is anymore

When I go for my oil change I'll have my mechanic look at it

 

[Exproblems]

Hey Guys,

My 2003 Explorer 4.6L V8

Last 3-4weeks ive been noticing if the vehicle is warm or cold I find when I accelerate with my explorer mind you I do have a K&N air filter in the air box which is clean I checked that I get a whistle noise.

I also have a K&N drop in filter and have had it for 2 years and I "do not get" any kind of whistling noise coming from the air intake. Ever have the "Throttle Body" cleaned out before?

 

[BlackOut33]

Yes buddy I cleaned it out last year

 

[BlackOut33]

I'm going back to a stock filter I've been hearing the kn can clog the maf and all sorts of things
I need my baby to last for as long as she can

 

[D Hook]

I'm trying to get rid of my K&N setup that was on the truck when I bought it. Want to go back to stock air box.

If anyone has a stock box and hose they'd like to trade, let me know.

 

[jp450]

I'm going back to a stock filter I've been hearing the kn can clog the maf and all sorts of things
I need my baby to last for as long as she can

As long as the filter does not get over oiled, it will not harm the MAF. I had one on my 99 Ex for close to 200k miles without any issues. I now have one on my 05 and have never had any problems.

 

[BlackOut33]

I'm going to clean throttle body maf iac
Then going to wash the kn filter really well spray it lightly and then go from there and see what happens

Anyways bro good night I'll let you guys know when I'm all done it

Night and thanks for the help

 

[Exproblems]

I'm going to clean throttle body maf iac
Then going to wash the kn filter really well spray it lightly and then go from there and see what happens

In case you did not know, there are "specific" types of cleaners for the Throttle Body and the MAF sensor and it's written right on the product can. You can buy these cleaners in most parts stores for approx $7 a can. Also, when cleaning the MAF sensor, try not to drop it on the ground. It has a couple of very fine wire electrodes in it that could break if it takes a hard enough hit. A new MAF sensor runs around $150. On the K&N filter cleaning, technically they do not need to be cleaned for 50,000 miles of use, unless you drive in really dirty, dusty conditions. After you clean it, make sure you give it time to thoroughly dry before applying a light coating of K&N filter oil. I know some people just re-install them cleaned and dry, no oil. BTW, my Honda Foreman ES ATV came stock with a K&N air filter and no problems with it there as well.

 

[BlackOut33]

Hey guys got the throttle body cleaned today cleaned the kn air filter flat bed
Start up the suv in park idle is st 1000 rpm for a bit then slowly moves down to 900rpm
Pit the vehicle on drive it stays at 900rpm then slowly drops to 900 to 800 rpm in between

My mechanic checked for leaks nothing found

When I drove past 2000rpm a very small faint of a whistle

I asked him should we clean the maf and iac he told me no need because it's clean.

I'm thinking it's the throttle body cleaning that's working itself out
Gonna take it for a nice ride this week n give it some juice

Night guys let me know what u think

 

[D Hook]

In case you did not know, there are "specific" types of cleaners for the Throttle Body and the MAF sensor and it's written right on the product can. You can buy these cleaners in most parts stores for approx $7 a can. Also, when cleaning the MAF sensor, try not to drop it on the ground. It has a couple of very fine wire electrodes in it that could break if it takes a hard enough hit. A new MAF sensor runs around $150. On the K&N filter cleaning, technically they do not need to be cleaned for 50,000 miles of use, unless you drive in really dirty, dusty conditions. After you clean it, make sure you give it time to thoroughly dry before applying a light coating of K&N filter oil. I know some people just re-install them cleaned and dry, no oil. BTW, my Honda Foreman ES ATV came stock with a K&N air filter and no problems with it there as well.

Any advice on cleaning the filter? What to use?

 

[BlackOut33]

If you have kn buy the kn recharger kit it's like 12.99 or something gives you install instruction. Just don't over spray it will cause the maf to clog up
I

 

[OffTrac]

I didn't have the whistle until after everything above was cleaned, including a seafoam treatment. Almost sounds turbo-esque. Doesn't bother me but I can see how some would not like hearing it. My truck runs beautifully though.

 

[Exproblems]

Any advice on cleaning the filter? What to use?

On the filter in my Explorer I haven't fully cleaned it yet because it has only 10k in mileage on it yet and doesn't look dirty at all. For now, till it needs a good cleaning and re-oiling, I just take it out of the air box once or twice a year and lightly tap it on the ground to loosen any larger objects from it if there are any. I wipe out the air box as well while I'm at it. When I do go to clean it, I'll use the cleaner/oil kit in the web link below. I'll spray down the filter with the cleaner first and let it saturate, then hose it off good with water and let it dry before applying a "light" coat of oil. Give the oil some time to saturate the filter element before re-installing it into the vehicle. Wipe off any excess oil that gets on the outer screen and sealing ring around the filter. I have a friend who owns an older model Mustang GT 5.0L, this is how he cleans his K&N filter without any problems. On my ATV, the K&N filter for that is a different design, one made of rubber and foam that you can squeeze or ring out in your hands using a bucket of water and dish soap. You re-oil the foam part when done cleaning it.

http://www.knfilters.com/clningacc.htm