bstratton

I have searched these forums for a similar problem and perhaps my description is where I am missing it, but here is my problem....

I have an '06 Scab 5.4L Lariet 2x4 with 100k miles on it. We had taken a trip a few weeks ago up to the mountains and it was a very hot 97 degree day with lots of traffic. We hit a traffic jam near the end of the 400 mile trip and sat on the Interstate for a long time. Once we start moving (stop and go for an hour or more) I would notice that when I would accerate I would hear a deep throaty sound come from the engine. For you older guys like myself, it sounds alot like a 4bbl air sucking sound...but I was only slowly accerating. Once up to speed it would not do this until it went under a load going up hill in the mountains... and once I would get up speed and it would shift up to normal gear it would stop. Never hear it when at driving speed.

Ever since then it will do the same thing from time to time when I am at low speed (5-10mph) and give gas to speed up or under a load. It only happens for a couple of seconds, or until it shifts up. I am only hoping that there is not a problem with the tranny, but the sound seems to be coming from the engine and not under my feet.

Any ideas before I take it to the shop would be greatly appreciated!

OKStateF150

Is it coming from the front drives side of the engine bay? If so, could be your air intake. Mine did it when I was in the mountains. I have a cold air intake so it's usually kinda loud but it was noticeably louder at altitude due to the thin air. Not sure why it would still be doing it now, but it sounds like the same intake noise I noticed when I was in new Mexico on vacation.

bstratton

Thanks for the reply... but I don't think it is normal. I have had this truck for several years and had never heard this before. It also does seem to have a slight loss of power when this happens. By that I mean if I am accelerating and feel the truck pick up speed, it seems to no "pull" as hard when that sounds occurs... but it does pull and will accelerate enough to gain speed and eventually stop making the noise.

The only reason I am concerned about the transmission is that several months ago I was on the highway and attempted to pass a car. When I pressed the gas to go around, the truck down shifted, the rpms jumped up like it should, but it seemed to hang there and not upshift when it should have. I had to back off the throttle to get it to upshift. I was also getting shudder when pulling out and turning left or right. After searching the forums I found that I probably had clutch plates slipping and as a first try I added the tube of "miracle cure" (not sure what it was now... but Ford had it and knew what I needed) and that seemed to fix the shuddering problem. I've not had the nerve to try the stress test and stomp on it while on the highway... I need this vehicle to get to work and don't want to spill my gears out on the road.

nickpatton_189

iTrader: (2)

Is it the fan? I know when my truck gets a little hot it sounds like a damn big rig

OKStateF150

Fur Away 07' Screw

Ok my first post.
2007 f150 5.4 3 v. 49000 miles.
I get a harmonic vibration under load. ( boat / air-condition and hot weather).
Usually going up a onramp. Slow acceleration ( long on ramp)
Took it in last Friday Ford had it all day could not duplicate the sound. Service advisor said come back Monday and leave the truck with us for a few days.
But do a ride along. So I had the mechanic and service manager. I duplicated the sound 3 times. 1 time the mech says is that the worst it gets? I said no. They recognized the sound each time it happened. And still insist the truck is running normal.
Well I expressed my un satisfaction with the end results. I will be getting a second opinion.
As for the symptoms does anyone else have this issue?

screw04

I had this issue when I bought mine, exactly the same and it drove me nuts. To the point where we couldnt figure it out and we yanked the motor. Still could find nothing, then we dropped the oil pan the rest of the way off and the baffle inside had broke off and was floating in the oil. Got a new pan and it went away so I guess thats what it was. Not sure about yours but it cant hurt to drop the pan on your next oil change and look. Not to hard, we spent a week of looking at stuff on the motor before we dropped the pan

BRichards118

Im new here but I have a 04 F150 supercrew doing the same thing. Did you ever find a solution?

BRichards118

It has something to do with the torque converter, it's a "torque converter shudder" as they call it. The reason the guy above me had it go away was because he pulled the motor which the torque converter will normally stay attached to when it comes out.

techrep

iTrader: (1)

Check the gasket/seal on your air box....there's a thread on this...