Hi all,

I'm hoping I can get some help. I have a 2007 F150 SCREW/Lariat with 6,400 miles on it. I'm a recent Chevy convert and really like my truck.

Recently, I've discovered a vibration at around 1,700 RPM. It sounds/feels almost like a timing or air intake issue, and it occurs in all gears including Park or Neutral. Seems to be at its worts at 60MPH.

I took it to the dealer today and got nervous when I saw the tech taking the rear suspension apart. Seems they felt my suspension was out of alignment and this would cause the vibration. That makes little sense considering the occurenc in non-drive gears, but OK. On check out, my service advisor tells me that the tech got everything tightened up, including a loose clamp on the motor, and that should help. She also informs me that the driveshaft appears to be a little bit out of round, so they are going to order one and that should help the vibration at highway speeds. Dealer also says they reprogrammed the computer.

So I hop in my truck and run it up to 1,700 rpm in park and it is just as bad. At this point I'm late for a pretty important meeting, so I head out and call to let them know I still have an issue. Waiting on a call back.

I have two questions:

1) Any idea what is causing the vibration? What should I ask my deal to check?

2) How in the world does a brand new truck that has only seen 6k highway miles end up with a driveshaft that is is "out of round"?

Please help...I'm getting nervous and my Chevy pals are making fun of me!

--David

 

There are several TSB on vibration issues on these trucks, I think the dealer was just performing a few of them to eliminate possible causes rather than spending time analyzing your particular truck.
It is not so uncommon to have defective drive shafts on new trucks, but I have heard that a lot of vehicles can get unseen damage from the carriers once they leave the assembly plant.
Congrats on losing the Chevy, I did the same thing. I suspect some of these annoyances are because the rest of the truck is so solid and quiet that any little tick or shake seems amplified..

 

I would like to think you are right regarding the quietness amplifying the sound, but it's not really a sound issue.

The whole truck vibrates, like a tire is out of balance or something. In fact, that was my first thought until I realized it did it in park and neutral.

--David

 

I'd have them check the crankshaft bearings cause a vibration in Park is not the rear end.

Does it go away once you get it above 2K ?? and I guess it's not showing any codes.

 

There is also a phenomonon called "low speed stumble" usually a cop is misfiring.The Ford diagnostic bay equipment can check for "cylinder misfiring history". Good luck

 

I would have to agree, that, there seems to me a misfire here. Even the newest of parts can fail. Sometimes, (unless you check) there is normally a bad egg in the carton.

Just from the words of explanation, I would have to guess a misfire or your rotors in the back are out of ballance. !BUT!, that does not explain the park and neutral, same feeling!

I would almost have to bet all of it on the misfire! Are you partial to the dealer doing all of your work or do you do any yourself. Dealers sometimes run you in circles till your warranty is up and then hit you HARD.

I would try to read all of the TSB's on this site and what ever you can find and try to run the problem down yourself. THEN, deny you ever did anything and tell the dealer what you want done. It is under warranty and they have to honor it. AS LONG AS YOU HAVE NOT ATTEMPTED ANYTHING YOURSELF OR MODDED ANYTHING! So, if you do, do anything, DENY THAT YOU DID IT WHEN THE DEALER ASKS! They will do anything they can to get out of the warranty.

 

FWIW, there have been some flex plate issues with the 07s. Yours may be one of them. There is no TSB or recall for this. I wouldn't let this go, a vibration translates into excessive wear somewhere.

 

Thanks for the suggestions so far. Where do I find a list of TSBs on this site?

The problem does go away over 2k rpm. I would think the dealer would check for a misfire and replace something as simple as a plug or even a bad cop before they tear down the rear-end and order a replacement driveshaft. But, I may have to suggest that to them. Also, if it were a misfire, I would think the vibration would occur from idle up to some point in the rpm range. Instead, it seems to only happen between say 1,400 and 1,800 rpm. I'm perplexed.

I do all of my own work on my vehicle, including replacing a bad lifter on the wifes old minivan. But I bought a brand new truck, and make a brand new truck payment for a reason. First new vehicle I've ever owned. I think the dealer is going to have a long way to go to get me out of warranty. Truck was purchased in June and has 6k miles on it.

What if I took the truck to another dealer for a second opinion? Would I get anywhere with a dealer that I didn't purchase from?

I don't know if I'm paying closer attention or not, but the issue seems worse today. Like I said before, I love this truck and I really don't want to start worrying everytime I hear/feel a squeak or rattle.

--David

 

That is my big concern. How much damage have I already done that won't rear its ugly head until mile 36,001!?!?!

I guess the flex-plate could also affect park/neutral as well, right?

What about a harmonic balancer issue?

--David

 

does it show any wiggle at idle?

 

Congrats on your purchase,

I myself have had a similar had a problem when I purchased my new truck .. 2002, some time ago now!lol I feel your pain, very fustrating and countless hours at the dealers, loss of work, and paying for a new car, when the whole purpose was not to have any issuse hense the expression "new car".

Anyways, for myself they had my truck for a toal of a month, must have had the the whole truck apart twice, drove the thing around with sensor's for about three weeks...... my best advice would be to leave it with them, request a rental car for free.... do not pick up the truck untill the problem has been corrected.... and during this time you may have qualified for the "lemon law" and the company, not the dealership will be responsible for a new truck.... again this process takes forever and makes you never make you want to purchase a new truck again.....

The problem with my piticular truck was the rear end... humming noise at all speeds... 3.55ls ..... I guess ford had some problem with some of these... They ended up replacing the whole rear end... I did quality for the new truck... just to stuborn and so pissed ... did not want any more hastle ..

hang in their!

 

Not a bit. It's almost too quiet

I had the wife come out this morning and hold it around the 1,700 RPM range while I crawled underneath to look for tranny/exhaust wiggle. The only place the exhaust seemed to move was in from the collector forward. At least there is nice isolation in the exhaust hangers.

So I had her do the same while I popped the hood. The motor was rocking back and forth like a top fuel dragster's motor when it's staging.

So, my new plan is to go back to the dealer and make the service manager look under the hood with me while someone else (maybe the cute female service rep) holds the truck around 1,700 RPM. Maybe then they will at least accept that it's not a drive shaft issue. I will still take the free drive shaft though!

More to follow...

--David

 

Good luck i hope it's something simple

I've seen a dude replace an engine cause it wouldn't run, too bad the new engine didn't work either. He found out an engine doesn't run to good on an empty tank

 

Something else everyone may want to know about these trucks. The ETC (electronic throttle control) system is designed to work with a torque load on the engine. If you are in park and making the engine run above it's normal idle rpm, with no torque load, the PCM will adjust the throttle opening up to a certain rpm until it decides it is not in control of the throttle it will induce a misfire to reduce rpm. Surely 1700 rpm would not set this off, ususally it would act like a rev limiiter. That said, when engine managment issues arrise, and it is not the basics ... primary and secondary ign, injector wiring and injectors, or fuel delivery>> updating with a reflash may be a common maintenance item to consider.
I would not guess it would be rotating assembly problem if the vibration goes away at 2K rpm. And yes if you have time, feel out your local dealers. Some have a big turnover of staff from time to time and it is important to find a good one and establish a good relationship.

 

I get the same vibration load, or no load.

Again, if it was a mis-fire, wouldn't I feel or see it at idle or are least across a larger rpm range?

Dealer says they reprogrammed the computer too.

--David