2002 windstar engine whistle

just had the van serviced. got a tranny flush, rad flush, steering flush,
fuel injector service, oil change etc ,etc

a few days ago wife noticed and pointed out to me a whistle coming from the engine area. in the van this is barely noticeable. i opened the hood and had her give it a bit of gas and here is what i got

the whistle is just a bit more noticeable, it happens ONLY when gas is applied, at engine idle there is no whistle just normal engine noise.

when she gives it a bit of gas and the barely noticeable whistle is present and holds the gas, the whistle is steady.

i am nearly 100% (99.999) certain it is coming from the side of the engine where the alternator and serpentine belt is on.

any thoughts or ideas greatly appreciated.

should mention the alternator was replaced at crappy tire during the summer because the ford one died in a bog way.

thx again for help

rob12345:banghead:

Does the whistle sound mechanical in nature or is it truly whistling air?

Whistling is a classic sign of a vacuum leak; the air going through the leak really can whistle. But I haven't heard of this sound in a Windstar before.

Belt-related problems can also show up as (more mechanical) sounding whistles. Bad serpentine belt idler pulleys can sound like this.

near as i can tell it sounds like whistling air. if i strain in the seat i can hear it. with the hood open there is of course the normal engine noise and its very difficult to hear it then, but it is there.

also i listened again and it si definitely on the alternator/serpentine belt side.

can a bearing make such a sound only at slightly higher engoine speeds?

thx for the reply

rob12345

I've run into idler pulleys that are noisier at certain RPMs.

Use something like this to track down the noise to a particular location:

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=41966

My '96 makes a whistle sound....
Also...I noticed more of the sound when I replaced the serpentine belt with a Goodyear "Gater Belt".

I would expect a idler pulley or tensioner pulley bearing to make more of a growling sound....but then.....that is what my idler pulley bearing did.....as phil mentioned, mine was only above a certain engine speed.

Tough to get a handle on this one without actually hearing it. 'Whistling' is tough. That usually makes me think blowing air, but of course can happen with sucking if the opening is the right size, usually very small. Larger opening would tend to make a slurping or sucking sound- that is if it was a vac hose that was completly off.

I have a bad idler bearing and it doesn't make a terrible sound. The races in there are plastic with metal balls. Poor quality but not likely to make noisy grinding on my 2001.

I've bought belts from crappy tire that were out-of round when measure with a micrometer and they tend to make some noise but not usually constant. When CT changed your alt did they change the belt?

And finally, my Ford factory alternator makes a horrible grinding sound that can be felt in everything connected to it. But keep in mind that CT usually gets factory second parts so there is a possibility you are dealing with a lousy alternator. It may even be something as simple as the new brushes in the alt.

But definitely get that scope. With a little experience that can help you pinpoint the sound.

when CT replaced the alternator they did not replace the belt. they had to take it off to do the alternator, they still wanted $35 to put a new one on. they called it a remounting charge or something like that. i declined. i was planning on having it done elsewhere.

anyway, the noise seems to have stopped for now. i have absolutley no idea why. however i bow to the expetise here. its probably not a vacuum leak, if i understand things correctly they dont just "go away' on their own.

its probably what was mentioned here several times. a tensioner or idler pully whose bearing(s) is slowly going on me.

i will have to wait and see if it starts up again. i hate that, when the problem goes away by itself, cuz i usually wait with baitted breath for it to come back, or go out and get one thing at a time fixed.

anyway, i would like to thank all for the replies and taking the time to do it. i would especially like to thank for the pictures of the brake and other jobs on a windstar.

they will come in handy.

if it comes back i will make another psoting as to the fix. time to browse. this is an excellent forum

Have to keep in mind that a failing bearing is unlikely to just stop making noise. It will more likely get louder if anything. So it probably wasn't that. If you feel compelled, an idler bearing is easy to change and is even easier to pop of and inspect. They are cheap too.

My suggestion about the alternator brushes may still be valid and let me explain a bit. The brushes are usually a rectangle shape and they contact a round surface. When new a minimal amount a surface area may be in contact with the shaft which could cause a noise. Similar to the resonance in brakes. As the brushes wear in more surface area comes in contact and the brushes start to take shape and glaze a bit. As the surface area that comes in contact increases (the brushes become rounder), the noise should change in frequency, likely decrease pitch I believe.

That's just my guess of course :)