Anyone ever heard of this?

Sometimes I get this loud hum coming from the engine compartment when the engine is at low rpm's, like between 900 and 1200 rpm's. I mostly can get it to happend when I reverse or accelrate very slowly. The only thing is it never last to long, so by the time I get the truck in park and the hood open, the hum is gone and I can't pinpoint it.

Anyone have a clue or a starting point to find it and fix it.

This is the truck of noises, first pitman arm, got rid of that then a rattle. Found out what that was now this hum.

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black 97' x-cab 4x4, 5 speed 4.6, black westin nerf bars, pilot ground searchers, borla SS split rear exhaust, K&N genII, bosch +4 plugs, superchip, flexalite electric fan, v-tech oval side window covers, IAS shocks

premier 720, pioneer 6cd changer, 12 premier sub, premier componets, 2 soso amps

still to come: new spark plug wires, new rims and tires, maybe a supercharger eventually.

 

My truck has a humming noise that, so far, only occurs at idle in cold temperatures. I recently removed my WMS velocity tube to see if this was the culprit, but temperatures have not been as cold recently, so I have not isolated the problem yet.

See this other discussion:

https://www.f150online.com/f150board...ML/002843.html

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2000 F-150 XLT Sport, Silver 4-door Supercab StyleSide
Short Bed (Only way to fit in the garage)
17" Sport Wheels with BFG tires, 3.55 R, 4.6l V8, Auto (First one in 20 years)
In-Dash Single CD Player, 60/40 Split bench dark graphite

Mods So Far
K&N Filter, Gatorback Spray-In Bedliner, Llumar ProShield Window Tint
WMS Velocity Tube, Black Westin Step Bars

Future Plans
Superchip, Upgraded Speakers/Stereo
FlowMaster Exhaust

[This message has been edited by Y2kXLTSport (edited 01-15-2001).]

 

Does the sound or noise sound like its in front of you?? My truck did this too. First I tried the heat sheilds on the converters, not it. Then check all around the engine. This noise is only heard inside? My noise was driving me nuts. I went to Ford they had it 3 different times at the cost of over $200.00 with no luck in a fix. Finally I started looking again. I unhooked the brake booster vac. line no more noise. So I had to get a longer hose with a plastic inner liner & this solve the problem. I hope this helps!!!!! If not their maybe something else You can try. E-mail @ Terrylariat1@aol.com
Lariat#1

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1997 Red/Silver F150 Lariat Flareside 3 Dr. SC..... ORP & Tow Package, Complete Lariat Option Package ,{APPEARANCE} GTS Projector Beam /Carbon Fiber Headlite Covers,AVS Tail Lite Slots & Door Sill Protectors,Flareside tail lites wired to work upper&lower lenses together,Owens Fg. Step Boards, Tinted Windows,Ford 2-Piece Bra,Lighted Ford Logo in Grill,20" Chrome Exhaust Tips,A.R.E Bed Cover Lid,Pendaliner Inner Tail Gate Protector,Zie-Bart Total Paint & Under Coating W/ Sounder Deadener Protection, Lariat #1 Plate under glass on Front Bumper,Custom made Ford Red Window Decals,Blue Tinted Rear Lic. Plate Protector,Blue Billet Valve Stem Caps, Ford Lited Hitch Receiver Cover that works off brakes lites, HD Bed Mat, Red reflectors above Rear Bumper {PERFORMANCE} 4.6L WINDSOR Auto, 3.55LS, 4-Wheel ABS,Platinum 3 Spark Plugs,K&N Air Filter W/ modified stock MAF side air box,Outerwears Blue Pre-Filter Cover,Tornado Air Man.,Perma-Cool Oil Filter Relocation Kit,Motorcraft Racing Oil Filter FL-1HP,Dual Exhaust System W/Stock Muffler,NAPA Ceramix Carbon Ceramic Premuim Brake Pads(Front),Goodyear Wrangler A/TS Tires,55 Watt Halogen(replacement) Reverse Lites, Pilot 55 watt Halogen (add-on) Reverse Lites on Hitch under truck,Driving Lamps upgraded to 55 Watt Cool Blue Halogen Bulbs,Pilot Bright Whites headlite bulb replacements 65/55 watts,Driving Lamps(Foglites) work W/ High Beams On & Driving Lamps(Foglites) also work (ON or OFF) W/ Park Lamps On W/Switched Relay, A.R.E Cover wired W/interior(dome) light wired to a mounted door jam switch thats wired to hood light,SurgeGuard by Calterm {AUDIO} Stock In-Dash Cass. W/6 Disc Changer & 2 Stock Speakers(back) & 2 Pioneer TS-A6865 3- Ways(front),Black felted inner front door speaker openings , all speakers dynomat lined,Trenz Billet #3 Antenna {SECURITY} Ford Total Security System W/ Motion Alarm All on factory Key Fob,Ford Warning Decals on Windows,A.R.E Cover & Hood also wired to Alarm System, Hitch Pin locking system This is LARIAT#1..... IN The Great State Of Indiana "Where more than corn grows in Indiana".........http://hometown.aol.com/terrylariat1...page/auto.html A Very Proud Member of ...www.f150online.com

Soon to have Flareside Rear Step Bumper re-plated (Triple Chrome Plated)

 

I can definitely hear mine outside the truck. It is coming from the engine compartment, but only happens when it is cold outside (below freezing).

 

I also get a humming noise, only on cold mornings. It only lasts about a minute or two. I haven't had a clue as to what is causing it, but sure would like to know what it is.

 

Is the noise you're talking about almost a howling or groaning noise? I have that too, only when it's real cold, and usually when I am coasting up to a stop. A tap on the accelerator will stop it.

I thought maybe it was some weird resonance in my Airforce One FIPK.

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1998 F150 Lariat 4x4 Extended Cab. 4.6L Auto
Mods: Superchip
Airforce One
BFG 255/85R16 M/Ts
Planned: Ravin Z-55

 

The hum I get is definatly from the engine compartment. And it usaully happens when slowing down or accelerating, just above my idle RPM's, around 1000rpm. And it's just strated to happen now that the weather is colder, though sometimes it does it when I think it's decently warm outside (for this time of year).

 

This weekend the hum started just as I pulled in my driveway. I was able to open the hood and look around while it was still making the noise. It seems to be coming from the fan shaft. Any known problems with these? Any place to lubricate it?

Thanks,

Jay

 

dont know about the fan idea, but my dads f250 HD has a whistle or humming noise. Its more pronounced when its cold out and during acceleration. We figured out its a vacume line somewhere, but since the truck still runs fine we dont mess with it.

 

Are you guys sure it's not the clutch fan locking up? It makes quite a roar. Mine had similar symptoms till I put in a PermaCool electric fan.

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97 Lariet-sc-4.6-4x off road-auto-3.55 LS-
superchip-K&N-3"
pvc air box mod-Granetelli MAF

 

Well, mine wasn't locked, since the fan was still turning. But that did seem to be where the noise was coming from.

 

Yhe hum I have is definately not my fan, I have an electric fan installed that works fine.

I read in one of the other posts that someone who put on a FIPK and didn't use that little plastice box piece on the 4.6, then they replaced it and the hum stopped. I might try this because I did use a supplied hose instead of the plastic box, I just don't know where I placed it.

 

jayf
by locked I mean there no slippage between the fan hub & the fan - driving the fan engine speed. Mosty the fan runs slower than the engine. You should be able to turn the fan by hand with the engine off.