I've been getting a very loud howling/whining noise from my 98 ranger for a few years now and I'd at least like to know what it is for future reference. It only happens in hot weather, never in the fall or winter. If the truck is cold it will not make the noise. If I drive it for a while on the highway, stop somewhere and park it will howl loudly when I start it until I drive for a while which leads me to believe the transmission is overheating. I suspect it is either the pump or the torque converter because the sound disappears over 1500 rpms. It's not coming from the intake, the sound seems to emanate from the rear of the engine compartment but it's so loud I can't pinpoint it. The fluid has not been changed in the trans for 90,000 miles so there's a good chance that has something to do with it. I just want to know if anyone else has a similar experience. I'm not in any financial shape to repair the transmission but I'd at least like to know what it is. Thanks.

 

to me it really sounds like your tranny. hopefully for your case it isn't. your sure it's w/ the drivetrain? cause we had a howling noise with our windstar and had the tranny replaced for $1500 and all we needed was new tires.

 

Based on the symptoms I'm having I'd say that it is something in the transmission. There's no engine noise, I have brand new tires and it's done it over about 4-5 different sets of tires. If it didn't disappear with rpm's and only do this when it's hot out then I'd say it was something else but it's been a bugger to figure out over the last 4 years.

 

The IAC valve has been known to make a howling noise. And since your running a K&N air filter, there is a good chance your IAC valve and throttle body are gummed up from the oil and dirt the K&N passes.....The first thing to try is clean the IAC valve, and see what affect that has on the howling noise.

 

Where exactly is the IAC valve? I cleaned my MAF sensor once and some other little sensor in the intake tube but I'm not even sure what that was. I've heard someone mention the IAC once before to someone with a similar problem, makes me wonder.

 

Brb, going to go out and look at it... I am intrigued to say the least.

 

The IAC valve is located on the upper intake just behind the throttle body.
This is what it looks like:




The other sensor in the intake tube is the IAT (Incoming Air Temperature) sensor.......

 

Did you consider the clutch fan engaging to cool the engine? It's hard to diagnose without hearing it but I would look at the fan.

 

Thanks for the pic. I went out, pulled off the IAC and throttle body, had some electric motor cleaner and cleaned out the IAC good. The spring inside looked very gummed up so maybe it was sticking? I also got some carb and choke cleaner and scrubbed the whole inside of the throttle body. The back side of the butterfly had an easy 1mm thick layer of varnish on it as did the body itself. When I put it back together I didn't hear a thing, went and drove it for a few minutes and completely silent. I think it's too early to tell because the temp outside cooled down but I'll be driving 20 miles to Reading tomorrow so that will tell the tale.

 

Just a little update. I went out around 9:30 to pick up my sister, started the truck and again, a loud howling noise. Just out of curiosity I popped the hood and tried to locate the source. I read on the explorer forums about a guy who had a similar problem and he pulled the black cap off of his IAC valve and it stopped. I though "what the heck" and yanked it off. Sure enough, the noise stopped altogether. As an experiment, I placed my finger over the hole to block it off and the noise came back obnoxiously loud. I think now, that the IAC valve is bad and sticks somehow, pulling the little black cap off cured the problem until I can get a new one. Takeda was spot on with what was causing the sound, thanks for the heads-up.

 

Yea, I knew what the problem was just by the title of the thread. Its so common, many people refer to it as the Ford 4.0 Moose Call.

 

Do your truck a big favor, and replace that K&N with the OEM paper filter!
Dirt and oil are the only things that the K&N passes more than the OEM paper filter, so there is no advantage to the K&N. With the OEM paper filter, you won't have to clean the MAF, or worry about a gumed up IAC valve again. My 1999 3.0L has >150K miles, the MAF sensor, throttle body, and IAC valve are like new, and they have never been cleaned. I've only used Motorcraft, or Purolator air filters, changed once a year.

 

did this IAC valve end up fixing the problem? I've got the same exaclty and replaced the fan clutch but no go. I't sound like the fan's having problems breathing when the clutch kicks in but is better when it's cool out. Thanks for the input

 

Changed fan clutch now I have howling noise. Any ideas?