vibration sound problem-help please

[terics]

re 2005 6cyl lincoln ls -- a week after buying the ls last fall ( and just after the ford autostart was installed ) I started to hear a vibration noise when pushing the accelator but felt no vibration ( like loud bees humming ) coming from deep in the front left dash or engine when the vehicle was cold when and only when accelerating at a low speed . When it starts if I hold the acc. at that spot the noise may go for several seconds .It is most annoying during in town driving as you often stop and start or are going at low speeds .It is ruining our enjoyment of the ls .
The ls has been taken to the dealer ( an excellent dealer with whom we have a great relationship over several vehicles )four times for this problem -- the dealer is 60 miles away so it is far less noticeable when I get there as the vehicle is warm by then --their best guess is that it has to do with the " heat shield " ( whatever that is ) and the last time they tried to fix it it came back worse .They checked out the autostart and said that it had nothing to do with the noise.They told me to bring it back if it continued but that seems senceless as no one knows what the problem is .
Does anyone have any idea what this could be ????? THANK YOU !

 

[l-m tech]

it could be the auto start that is causing somthing to go haywire.the resone you dont feel anything in the throttle is because your car has no cable that hooks up to the engine.the trottle position switch sends a signal to the pcm and the pcm operates a motor on the side of the trottle body to the desired opening.i dont understand how you didnt hear the noise until after the auto start was installed. i wish you luck and let us know what you find.

 

[pgilmore]

Lincoln LS low speed vibration noise

I am experiencing the same problem with a 2005 LS (6 cylinder). The problem appears to be temperature related, at least for me. I hear the low speed vibration noise only at around 1600 RPM's, and when it is cold outside (temperatures in 40's or below). It sounds like bees buzzing. The problem is that 1600 RPMs is where the engine speed is at about 40-45 MPH, so the noise is somewhat prevalent. The mechanic was unable to duplicate the noise (the car was tested on an unusually warm day). However, a mechanic friend suggested that it might be the horn, of all things, and indicated that a defective horn has caused those symptoms in Crown Victorias (which may have the same or similar horn). I have not had the car back in the shop yet to try and fix the problem. If the person who had the problem ultimately found a fix, I'd very much like to know what it was. The car is otherwise fun to drive.

 

[n8bachelor]

OMG my car started making this same "humming" noise about 2 months ago. Happens at around 1400 rpm and only at that speed. Also seems to be temperature related, once the car is warm or if it is really warm outside it doesnt do it. I am running a 2004 V6 with no modification to the engine. I havent taken it to the dealer as of yet since it is not a predictable problem. I got some "bad" gas at about that time that caused hesitation and the CEL to be on for a bit but I treated it with Heat and that fixed the problem quickly and the CEL went off. If there is anyone who finds out what is causing this problem please post it.

On another note what kind of gas mileage are you late model V6 guys getting? Mine hasn't been all that good since I got the car.
16-18city/20-22hwy

any input is appreciated,
n8

 

[pgilmore]

V6 fuel efficiency

I generally get 18.5 mpg around town. However, when accelerating, I generally do not go above the low 3,000s rpm. If I do a mix of highway and town driving, the mpg bumps up to about 20-21 mpg, depending on the mix. The one highway trip I took I got 25-26 mpg.

 

[TonyLS]

2004 V6; I get 23mpg, that's about 70% highway 30% city