Hey guys,

I hate to be one of those people with 1 post on a forum, asking for help with a problem but I have to be that guy. I have a 2010 F150 with the 4.6L engine.

For the last couple of months, my truck has had the same problem. When driving at a steady speed and usually around 2000 RPM (more pronounced at highway speeds) it begins surging up and down by about 200 RPMs and making a high pitched squeal sound. I tried to record it and it's posted here:

https://drive.google.com/file/d/0B-_...ew?usp=sharing

Help! I took it to a local mechanic who was unable to reproduce the problem. It happens almost every day I drive it, but not every time. Any ideas? Anything would be appreciated, I'm losing it here!

Thanks in advance!

 

bump

 

Watched/listened to your vid twice yet saw no noticeable fluctuation in rpm nor heard no squeal. If you haven't changed your serpentine belt recently, I'd start with that 'cus old belts harden, crack and then slip/squeal.

"and this little piggy said; wee wee wee"...

 

AC clutch cycling? Could be the ac clutch is done? When it's doing it. Turn off the ac and see if it continues or goes away.

 

Thanks for the replies.

There is definitely a squeal in the video, you have to turn the volume up pretty high to hear it because of the road noise picked up during recording. Also it was hard to hold the camera steady while driving so I guess that makes it hard to see the RPM variation. The serpentine belt doesn't look worn, but I was thinking it might be one of the pulleys.

I had thought of it being an AC issue, but it does it with and without the AC on.

Any other thoughts?

 

While getting a recording is a great way to help with diagnosis, I just want to make sure I remind you to be careful while you're driving, blandF150! Whenever possible, have a passenger hold that camera while you're behind the wheel.

Have you been to a Ford dealership for this? If you haven't I suggest getting an appointment scheduled, and having a technician ride with you. Feel free to use this to get started. Also, what's the current mileage on your truck?

Let me know how things go!

Brittany

 

Brittany,

I purchased the truck used in November from a Ford dealer. The day after I left the lot (without having purchased an extended warranty), the check engine light came on. I also noticed this noise I have described above. I took the vehicle back to the dealership and they said they would take care of everything free of charge. A couple days later, I got the vehicle back and the engine light problem was taken care of (was told it would have been over $1000 if I had to pay for it).

Still I was noticing this sound and RPM fluctuations. After numerous calls and emails, they basically didn't want to do anything to help me out even though they said they would fix it originally. Long story short, I am done trying to work this through a Ford dealership and Ford of Escondido can kiss my ***.

Just hoping some of the experts here on the site might have some idea or have maybe heard of this problem before. It seems like it would be a simple fix but I don't know...

Brandon

 

I understand, Brandon. What's the current mileage on your truck? I'll research any available options.

Brittany

 

I bought it at 76,000 miles and it currently has almost 84,000.

Also, over the weekend I got a new serpentine belt and replaced one of the idler pulleys. Still getting the same symptoms. Of note, it usually only happens when the engine is being stressed, such as when I am going uphill (not steep hills, but a moderate incline).

Any help you can provide is appreciated.

 

Thanks for giving me the scoop! I'll send this up to your regional customer service manager. All I'll need is a private message with your full name, VIN, servicing dealership (which can be a different one), and your best daytime contact number.

Brittany