Whistling noise in sync with RPM

[davidg]

I have a '99 SC 4.6 that has been in the shop for this problem more times than I care to think. Without rehashing the last few months here's what I know. During acceleration I hear a whistling noise that goes up/down with engine speed. It only happens in gear, you can drop it in neutral doing 40 mph and the sound instantly disappears. The dealer has replacing the intake, plugged the exhaust while brake tourqing, but the whistling is still there. Could it be in the tranny? Could it be a bearing/gear/port/??. I have had the overdrive OFF light come on once while I was driving (for no apparent reason) and several occassions when a serious hard clunk between 2nd and 3rd gear during shifting. Do any of these problems relate to one another? Has anybody out there experienced this? I've read the horror stories about arbitration and I'd rather have my truck fixed than get a lawyer. ------------------ Dave 1999 F150 S/C 4.6 V8 Auto

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[Y2K 7700 4x4]

My truck's TIRES make a noise similar to what you're describing when under acceleration -- sounds like gear whine.

Not to be 'cute', but turning up the volume on the radio and watching for parts in the rear-view mirror often is the best method while under warranty. Dealers can't fix what isn't brought to them in a basket (cheap shot, but it felt so good).

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XLT SC SB 5.4 4x4 3.73 LS

[davidg]

Not to beat a dead horse here, but something else about this is that the whistle increases in pitch the faster the RPM's go.
When it goes from 2nd to 3rd the whistle pitch drops back down and builds up to a higher pitch until it shifts again. Also, when the torque converter engages the whistle sometimes disappears, or is so faint I can barely hear it. Ford dealers say its intake air noise, but I'm really leaning towards transmission. Am I on the right track?

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Dave
1999 F150 S/C 4.6 V8 Auto

[davidg]

It's definitely not the tires. You can drive any other '99 or '00 F150 and not hear this sound. When going about 40-50 mph you hear the whistle constantly, and even if you lift your foot off the accelerator the whistle remains for a while, almost 20-30 seconds. Does this sound like something inside the transmission? Keep in mind if I drop the tranny from Drive into Neutral going 40 mph with my foot on the gas the whistle goes away instantly. Sound like internal transmission stuff? Any more thoughts on this would be greatly appreciated.

[kkirt1]

Is it soley dependent on engine RPM? Mine is. I hear the "whining" from 2,500 - 3,000 rpm no matter if the tranny is in 1,2,3 or neutral. I am leaning to either a vacume leak or the torque convertor.

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'97 F150 Lariat, Flareside, white/sliver, SC, ORP, 5.4 (FQR 8/99) running Mobil 1
Mods: 305/70/16 GY ATS, AR Baja wheels, dual exhaust, Smittybilt Nerf Bars, Edelbrock IAS Shocks, K&N Filter, Carbon Fiber Bug Gaurd and rigged the fog lights too.

Another great Ford truck site -www.fseries.com

[davidg]

Not solely on engine RPM, although I agree with you that it does it in all gears, except neutral. You can throw it in neutral going any mph and the whistle disappears, not even a trace. What about the whistle sound remaining for a while when I take my foot off the gas? I would think the intake side quits drawing air when my foots off the gas...what about the torque converter? Could it be a bearing or something?

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Dave
1999 F150 S/C 4.6 V8 Auto