whistling sound w/ 4.0 SOHC

[GMM]

I recently bought my 2000 XLT Explorer with 18K miles on it and noticed two problems. One was the timing chain noise upon start up which was taken care of with the recall on the tensioner. The second one is a whistling sound heard from under the hood that disappears when you come to a stop. I read that it may be cause by an IAC valve. I told the dealership about this and they replaced the valve. As soon as I pulled out of the parking lot I heard the noise again. Any suggestions as to what to try next?

 

[DocVijay]

Not IAC valve.

The problem with the IAC Valve seems to be that the sound shows up when you DO stop, not disappear. Mine would make the noise when idling. When I started driving, it would go away. Sorry.

 

[Joe93]

Are you sure it's coming from under the car? Because my friend has a 98 XLT and his will do the same thing. we found out that the noise is the wind going around his mirrors. My jeep had the same problem to. This might be the noise or not.

 

[2001ExpSport]

It's wind noise, you'll probably never find the cause unfortunaetly. Just turn up the radio louder.

 

[GMM]

I ruled out wind noise because the whistling continues for a second or two after I come to a complete stop.

 

[tbomb]

my 98 sohc is making a strange hissing noise (i wouldnt exactly call it whistling.) i think it might be a vacuum leak. sounds like its coming from behind the radio/ac vents area. its going in next week for a 30k tune up (im lazy.) im gonna have the mechanic do a thorough check on it.

 

[SCEXPLORER]

Originally posted by tbomb
my 98 sohc is making a strange hissing noise (i wouldnt exactly call it whistling.) i think it might be a vacuum leak. sounds like its coming from behind the radio/ac vents area. its going in next week for a 30k tune up (im lazy.) im gonna have the mechanic do a thorough check on it.

Keep us updated because i hear that same hising sound coming out of my dashboard.

 

[DocVijay]

Sounds like the vacuum system.

That hissing sound is probably aomewhere in the vacuum system. The cooling/heating system is run in part by vacuum, and a leak would sound like a hissing noise as air is sucked in. I'd check that first, as I believe it's the most definitive diagnosis.

 

[kgd102]

I have the same whistling on my 98 Sport when I'm both stopped and driving. It doesn't get louder or quieter just is always present. I took it to the dealer and he told me that it's the "planetaries" spinning and there is nothing I could do about and to just basically deal with it. I think the guy was just blowing smoke because he probably doesn't know what it is. It's pretty friggen loud and would love for a solution.

 

[tbomb]

guys, i will definately keep you updated on the hissing sound. im bookmarking this thread right now. my truck goes in on wednesday to MY mechanic, not a ford mechanic.

and lucky me, i found nother noise today. i now have an exhaust leak, but i just got my exhaust installed 2 weeks and 2 days ago, so ill call em tomorrow and im sure theyll fix it for free - this place is good like that.

 

[FordFanatic]

I had a whistling sound coming from the front end. They had to replace the dust seals. Luckily it was under warranty at the time. The dust seal tends to melt under high speeds in 4wd. So just have them check it out at the dealership. Hope this helps.
-cj

 

[Robert]

The dust seals will only whistle while you are moving. Squeeking dust seals is a common problem on '95 and up Explorers though. Ford's fix is to grease them.

 

[BajaXplorer]

Theres a TSB for a the seperator plate on the SOHC transmissions same symptoms=whistling it calls for a replacement seperator plate. I spoke with a tech and he HATES doing it Messyalthough it doesn't require removing the tranny.

Im thinking its that, IF your idle isn't effected

If it is affected then look at the IAC. Its appearing that these are failing way too early on the X, and this could be the reason theres a NATIONAL backorder on the IACs at this moment! The part # for IAC is 97JZ-9F715-BA

Sounds like that recall campaign that was on here a few weeks ago is something to look at!

TSB # 98-5-14 Whistling/Hissing Noise From Transmission During Idle

Dont forget the gasket that goes under there as well

have fun,

 

[tbomb]

GENTLEMEN, I FOUND OUT WHAT THAT DAMN HISSING NOISE IS!!!!

i just got off the phone with my mechanic, he said he couldnt find a vacuum leak if his life depended on it. he said that hissing noise is because in later model explorers, ford switched to a 'plastic' (im assuming some sort of plastic composite - possibly phenolics or something) and thats what makes the hissing sound - the air running through the plastic.

as far as my problem with my truck stalling goes, hes pretty much narrowed it down to the superchip. hes gonna do more testing tomorrow and ill have my truck back tomorrow night.

 

[Robert]

Ford issued a TSB for the whistleing noise on my '97. It might still apply to your '98. The fix was to instal a spacer between the throttle body and the intake hose.

A failing Superchip or one that comes loose from the back of the PCM will cause it to stall. Mine stalled twice before I pulled my PCM out and found my Superchip dangling off the back. I put it back on and secured it with duct tape this time instead of electrical tape and haven't had it stall since. The first time it stalled was pretty freaky. Driving down the freeway and lost all power to the engine. My engine still idled, however when I touched the gas pedal it stumbled and bucked. I coasted over to the side and shut it off and restarted it. Ran normal for the rest of the day. A few days later it did the same at a stop light. When I got home I pulled my Superchip out and found it loose.

 

[tbomb]

i had my truck in to ford and they said it was a vacuum leak and replaced my lower intake manifold gasket.

before i got my superchip, i read about how it might come loose, so ive alwasy used tape, and it has never come loose. i actually hope its my superchip, that way, all doubt is eliminated - yeah my truck will be less 'fun' to drive, but itll be reliable which is what i really need.

 

[Jon_Herr]

Whislting noise at idle & cam tensioners

I just got through having both problems addressed by my local ford dealer.

The whistling sound on my explorer is a known problem mentioned in the TSB a few posts back. I paid to have Ford replace the separator plate and while they were at it they did a transmission flush. The whistling is gone.

The whistling noise I'm talking about comes from underneath the vehicle. Not from under the hood or in the cab...

*************************************

There are different situations with the timing chain cassettes and / or tensioners. My dealer replaced them both. Note that my problem was intermittent. The chain would only 'rattle' on occasion. It had nothing to do with being warm / cold / etc.

Ford will cover all expenses related to the timing chain tensioner replacement. Including a rental car while your truck is in for repair.

Now, what Ford cannot control is the competency of your local dealer. My dealer is the best I've ever worked with for reasonable, intelligent repairs.

Good Luck!
Jon

 

[kgd102]

Jon_Herr: I had the separator plate replaced back in early 2000 and the noise had gone away. Since then it has come back though.

You are lucky to have a competent Ford dealer. I've been to 3 in my area and they all seems to have their head up their a$$.

 

[Slick]

I have a 95 sport, and since i put on my KKM true rev kit this sort of "whistling" sound has come up on mine too. I opened the hood and it sounds like it is coming right from my KKM. Anyone know whats up?

 

[SCEXPLORER]

I'm about 95% sure it is your IAC valve. I replaced my and others have too. You can get it for bout $50 from the Terry.