Hey Guys,

So it’s driving me nuts. This morning on my way to work this high pitched whistle was going crazy. Granted it was -5 out on my way to work, but any time it’s at or around 20 and below; then engine compartment has this VERY high pitched loud whistle coming from it.

My question is what the heck is it?

Don’t say, oh because it’s cold outside it should be doing it. I realize it’s doing what its doing because its cold; but every one of the five cars my parents own don’t do this. Granted none of them are Fords either.

Duke

 

maybe the belt squealing? Did the sound vary with the rpms?

 

No it wasn't a squeeling belt and didn't vary with RPMs. It'd just be while cruising, with your foot barely on the throttle going down the road. Could it be the gas coming out of the injectors at such a cold temperature?

It's the most obnoxious high pitched sound, and you can clearly hear it over the radio on a moderate sound level.

Just whistle loudly and as high as you can for about a 30 - 60 second time span and you'll know the exact sound this is making.

Duke

 

I wouldn't drive my truck if it was making a noise like that.
Something is definitely wrong. Sheesh, you have more problems
than Triton XLT dude!

 

Hey Now! I'm not driving it into any garages!

I'll talk to the dealer about it later today.

Duke

 

Duke - Mine has done the same thing for the past two winters. Have heard other talk about this on the board by no-one seem to have discovered what the cause.

With the mild winter we have had this year it has not been much of an issue but the temp dropped yesterday and the multi-pitched whistle is back. It is kind of a strange noise, sounds like three or four off key pitches under light acceleration.

let me know if you find out what it is.

How are the LS HID's coming along... Need some pics Duke

 

I noticed that it only happens in defrost or defrost/floor... so it must be something to do with the compressor trying to run in the cold.


Any yeah, it does get annoying

 

Subscribing, got the same issue

 

hmm, mine was doing it when the heat was just running regularly. It also happened when I turned off the HVAC controls to see if they were what was whistling.

I don't think it's hurting anything but it's driving me up the wall. I called the dealership and they said to bring it in next week to take a look at it. My response...and if it's not 20 or below, what then? He then paused and said, um yeah then we probably wouldn't be able to fix it. I just wanted to hand him a sign like Bill Engval talks about. Just something that says, Hello, I'm stupid. That way you don't waste your time talking to them. You can just see the sign and say, oops I'm sorry, I didn't see your sign.

Unless the compressor continues to stay on when the HVAC system is turned off, I don't think mine is related to that.

Duke

Side Note: We were waiting on silver carbon fiber to finish the HID retrofit. It should be done this weekend and installed next week. (Sounds like I've said that at least a hundred times)

 

Add me to the list. I wonder if it has something to do with the air intake? Mine does vary with RPM's, if I let off the gas it goes away. Mine starts around the 20 degrees mark as well.

 

the compressor runs in defrost mode (whether you run hot or cold air)

if your HVAC is off, then this wouldn't be the whistle/whine that some are getting

 

I noticed it yesterday when it was around 12-15 degrees out. I get the whistle at 2100-2300 RPM. If the temp gets up to around 20 or higher, no whistle or anything. It goes away after the engine gets warm (5 or so minutes after starting) and i won't hear it again for the rest of the time I drive the truck. I only notice it if it is colder then 10-15 degrees out and the truck has been sitting outside long enough for the engine block to completely cool down (aka all day at work.) I commented about this back in December when we had some brutally cold temps (around 10 days where we never got up above 10 degrees) here in Omaha.

I also noticed at that time a whistle when the truck was first started while the idle was high (I think in the 900 rpm range.) Again it dropped away once the engine got warm and i really wouldn't hear it. We talked about it in this thread back in December but never found any conclusions. I figured its just a belt whining until it gets warm. Interestingly enough, the RPM range I notice the whine changes witht he outside temp. Back when it was cold in december it was around 1000-1200 RPM but now that it is 15 out I hear it in the 2100 RPM range.

Going to go drive it at lunch here in 5 minutes and will see if it does it again. (3 degrees this fine morning.)

 

My '93, '97, '04 and '05 F-150's all had a squeel now and again on start-up during the winter. The '97 was the worst and would squeel even while driving. Nothing ever went wrong, and nobody ever could isolate it. Sounded like the noise was coming from the compressor clutch to me. It seemed to happen when it had rained/snowed the previous day and the current temperature was sub 15 degrees. Nothing to worry about I guess.

 

Well this thing is only two years from being sold then. I can't take this whistle sound and it's not related to belts IMO.

This is going to drive me up a wall every time it gets cold then. And that is like 7 mths out of the year in MN.

Duke

 

Frozen PCV Orifice? One of the largest problems in a PCV system is the freezing of the valve. Well on the F-150 there is a long tube that extends into the intake manifold, and there is no valve. It resembles something like a 3/8 diameter straw. The end of the straw can start to freeze over in extremely cold weather. The PCV “valve” is electronically heated, but it takes a few minutes to melt any freeze up. With only a small area not being frozen over this may be causing a whistle. Be careful if you try to remove the PCV valve, there is an “O” ring that you do not want to damage.