hey all,
recently i posted regarding a problem with a whining noise coming from the front of my 5.4L engine. it was recommended that i change the PCV valve to stop the whining, but i was driving today, and the noise is back and i can hear it in the cab. i had the alternator tested, and it is pushing 13.97 volts to be exact, which is acceptable. what else could it be?? i have a '99 with 79,000 miles. any advice would be greatly appreciated.

 

I have that same problem...oh wait that's called a supercharger!

Sorry I couldn't resist!

My thoughts would be maybe a slipping belt or a bad bearing in a pulley. If you haven't already thought of those, it might be worth a shot.

Later

 

I have the same problem. I happen to know that mine is coming from the A/C compressor because it only occurs (and always occurs) when the A/C is on. I charged the A/C system and changed to a Goodyear Gatorback belt, but neither helped. So I'm planning to look at the A/C pulley bearing next. Then if it still whines I'll just replace the whole damn compressor.

 

check your idler..you can easily pinpoint noise with an automotive steyhoscope.....

 

Mine does it with the a/c on but I think mine is because of the Airaid intake kit. Didn't start until I put it on.

 

Possibly the fan clutch. Leave the hood open and from outside the driver's door turn off the the engine. Watch the engine stop and if you hear the whine wind down for 1/2 a second or so then it's the clutch. That's the last thing to stop spinning. Mine went bad at roughly 90,000 miles. Don't buy an aftermarket fan clutch if you need one. I tried 2 different brands and both were locked up much of the time causing an extremely loud blowing sound and a loss of power and mileage. Ford wants $120.00 each. Buy a low mileage used one from the junkyard. Mine was $35.00 and works great.

 

idler pulley, tensioner pulley, aternator pulley, pump/crank shaft, or ac. I had the same problem after I installed ASP pulleys. I had an annoying whine while at idle. It was embarrasing, being a newer vehicle.

 

Are we absolutely certain it's not the power steering pump?

 

Yeah... I found that out this weekend on my own. I jacked up the truck and lubricated the A/C bearing (last-ditch effort to not spend money). Started engine and turned on A/C; no sound. Then it began whining a few minutes later. Went to listen for it, and I found it! Right inside the filter of my AF1.

LOL Oh, well. Live and learn. Now I just have to figure out how to make it stop whining. Like mf150 said, it is embarrassing, especially for a newer vehicle.

-Jeff

 

Kind of strange how it only does it with the a/c on. And I noticed that it whines when it gets warm outside, doesn't do it during the winter. Have you noticed that?

 

hey ucfperspicere, what did you use to lube up the bearing?

 

The PS would be my guess also. if it changed when he turned the wheel

 

I pinpointed mine to the cooling fan for the radio. I have the 6-disk CD unit.

 

I also posted about this, and still have the problem with my 98 5.4 that has 75k on it. I also replaced the PCV valve with no change. Mine happens only between 2250 & 2450 RPM. I had my wife rev the engine to that point and with me under the hood, it sounds like it is coming from deep within the top of the engine. I know that could be the throttle body, IAC, or any number of things. I don't think it is a vacumn leak because the engine runs the same as ever. The bend in the PCV elbow is not corroded like others have mentioned. I am certain it is not the P/S pump, and I don't think the AC compressor would make noise as if the top of the engine. One other thing, it does not do it during the first minute or two of driving. It seems like it needs to warm up just a little first.

Thanks,
Jim

 

Yeah, that is weird. Unfortunately my winter is only two months long at best, so it's not much of a break. That may have something to do with the mass density of the air being drawn in (and thus how much volume must be drawn in to get the same oxygen content). May also just be because I don't run my A/C in the winter.

I didn't do anything too evasive. I just sprayed some PB Blaster up inside the triangular plate on the front side of the pulley and inside the back side of the pulley, as best I could access. Either that did the trick or none of the noise was coming from there in the first place.

When I turned my truck back on and heard the noise again it was quite literally coming from the inside the filter. I would guess this results from one or both of the following design issues:
1) The top/end of the AF1 filter has a filter resulting in air flow through an O-shaped orifice, same as when a human whistles.
2) The mating surfaces of the filter and the hard plaster filter mount (which connects to the open-air side of the MAF sensor housing) are both threaded, causing a possible gap. I tried repositioning the filter, but no luck . I'd rather have a flat mating surface, but I didn't design the kit.

I suppose I'll just live with it for now. Embarrassing as it may be, I can still smoke a 5.0 Mustang.

-Jeff