Buzzing/whistle with changing RPM in 2006 F150
03-04-2019, 06:12 PM
#1
Buzzing/whistle with changing RPM in 2006 F150
I have a 2006 F150 with the Triton 5.4 XLT package. Pretty plain Jane truck. I purchased it last fall with 84K original one owner miles (89500 now). Runs great BUT it has what I can only describe as a whistle or buzz at certain points in time (Intermittent) and typically from about 1700-2000 RPM or at about 60 MPH. Comes back again at about 75 mph, but where I live, I don't get on the interstate that much to know if it is more frequent. When I first heard the sound, I would have said it was in the radio...much like back in the day when I would replace a radio in a vehicle and have the "engine buzz" with out a capacitor or resistor in power the line. The problem with that is it is present with the radio on or off. It is a crescendoing sound that cuts out abruptly at that 2000ish RPM's.
I had it into the local dealership and they had it for a week. The looked at PCV valve which was replaced and did not affect the sound. The also found a belt tension pulley that had a bad bearing and replaced that and the belt itself. This seemed to help in the short term, but the sound is back at as bad as before. They had a 30+ year Ford master mechanic on it and he was/is baffled. They feel that they have ruled out anything that could be a serious or detrimental problem at this point in time. To the driver, it sounds as if the sound is coming from the left front speaker, but to passenger, it sounds like it is just right of center in the front. As it only happens at higher ROM's, I can not hear it other than going down the road. I did hear it one time when the truck was sitting in the garage on a cold start, but can not say for certain if it was in the cab or under the hood. I can try to get an audio recording of the sound if I can post recordings here?
Any thoughts or opinions would be great
I had it into the local dealership and they had it for a week. The looked at PCV valve which was replaced and did not affect the sound. The also found a belt tension pulley that had a bad bearing and replaced that and the belt itself. This seemed to help in the short term, but the sound is back at as bad as before. They had a 30+ year Ford master mechanic on it and he was/is baffled. They feel that they have ruled out anything that could be a serious or detrimental problem at this point in time. To the driver, it sounds as if the sound is coming from the left front speaker, but to passenger, it sounds like it is just right of center in the front. As it only happens at higher ROM's, I can not hear it other than going down the road. I did hear it one time when the truck was sitting in the garage on a cold start, but can not say for certain if it was in the cab or under the hood. I can try to get an audio recording of the sound if I can post recordings here?
Any thoughts or opinions would be great
03-04-2019, 09:27 PM
#2
Member
Wild stab here... but check on the condition of the radio interference capacitors that are bolted to the front of the heads, on the inside corner of the valve cover, and their gray connectors a few inches back.
03-06-2019, 09:43 AM
#3
Mark
iTrader: (1)
Hope you didn't pay Ford for a PCV valve for your 5.4L 3V motor...
03-07-2019, 09:19 AM
#4
Senior Member
Had to laugh that the dealer doesn't know what it is but it's no serious! LOL! I'd remove the fan belt and see if the sound goes away. If it goes away then you have narrowed the problem down.
