My 2000 V10 6.8L Ex does this weird thing when I am drive but with the brake depressed, like at a stop light. It almost sounds like the engine is really annoyed that I am making it stop . It isn't loud but I feel this low level vroom, vroom sound and kind of feel it in brake pedal. I am not a mechanic or even a garage one, with the exception of being up close and personal the last couple months with my frame, drive train and suspension due to a restoring that part of my truck, I don't know much about engines other than the basic fluids, battery, fuses and belts.

This maybe normal? If not what should I check, what other trouble shooting?
Only thing that comes to mind is fuel filter maybe? If so, can someone tell me where it is and how to change it? I warned you I wasn't a mechanic...

Thanks everyone you guys are great.

 

For as much time as you just spent under your truck I bet you looked at that fuel filter 15 odd times...... it looks like this https://www.ford-trucks.com/forums/1...r-r-and-r.html and is under the drivers seat in the fuel line. Also my Grand Maquis w/ the 4.6l will do the same thing you described when the IAC is going bad

 

Ahhh you are exactly right and I know exactly where that is located. Anything I need to know before I open it and change the filter? Is there only one of these on the truck? Does a dirty filter make the engine rev higher than it should when stopped in drive?

Sorry for peppering you with questions. But it's on my Sunday to do list so want to head to the parts store and get a filter and if there is anything else I need.

 

I guess I should have read the entire post you copied, I got it - thanks for replying.

 

No prob. You got it. Should be a easy job. You just made me want to change mine out today too.

 

If you can feel it in the brake pedal I'm inclined to think you may have a vacuum leak. Your brake booster is powered by engine vacuum, and it sounds like you have varying manifold vacuum that can be causing, or a result of, your uneven idle.

Typically a plugged fuel filter will cause a lean condition when you're asking for lots of fuel, like when you are trying to accelerate or climb a hill. But idling is when your truck is asking for as little fuel as it ever will, and so if the filter were that obstructed I would think you'd see major driveability problems when you get on the gas.

If a new fuel filter doesn't help I'd look for a vacuum leak. Let us know how it goes!

 

Does it feel like it wants to accelerate briefly when stopped? If so, it could be the IAC valve sticking. You can try taking it out and giving it a good spray cleaning with carb cleaner. Replacement part is $50-60.

Here's where to find it. https://www.ford-trucks.com/forums/5...rsion-v10.html

 

That is exactly what it feels like and would explain why it doesn't do it all the time, only with the thing sticks. Thanks for the info - now I know what to do and where to find the part. Pictures help I could have looked at the engine for an hour and not figured out that was the IAC.

 

In case helpful:

https://www.ford-trucks.com/forums/1...e-for-v10.html

 

Moved to the Modular V10 (6.8L) forum.

Stewart

 

After I read everyone's response I got in there and took a look today, (with my step ladder) traced as many vacuum lines as I could find to their end point and sure enough I found one that goes to the drivers side brakes (sorry don't know the proper terminology) and it was pulled loose. I am certain I did that this week as I have been stripping the entire under body of this truck and sealing it, so I tightened that up and no more surging when at a stop.

Thanks

 

Glad to hear it was a simple fix!