My 2001 supercrew - 5.4 liter has a rough idle when sitting still - it is very suttle and appeared as early as 10,000 miles. The dealer said it needed new motor mounts and has ordered them under warranty (currently 28,000 miles). Does this sound right?

 

have you disconnected your battery at any time, if you have you have to relearn the way it idles, the directions are in your handbook, but if its really rough its probally something else?

 

David,

Hard to say. Really sounds like a 'shot in the dark' on the diagnosis but, maybe it'll work. I'm assuming that you're using Greenwood?

I've had good luck with them in the past but, if it doesn't work, I'd be on them like stink on poo to make sure that the problem is resolved.

Best of luck to you and let us know how it turns out.

RP

 

FWIW

I had developed a rough idle before installing my AirRaid intake. The rough idle was still there and I just lived with it.

Recently I started playing with different combinations to get optimum gas mileage. Things like Superchip and stock intake, stock intake and no chip, Premium vs regular gas, etc....

When I reinstalled the AirRaid intake , I decided to clean the MAF with BrakeKleen. As usual after each setup change I would reset the computer by disconnecting the battery. I would start the truck and let it idle for 15-20 minutes.

This time since I cleaned the MAF my truck now has it's smooth idle back.

BTW Superchip and Airaid intake gets the best MPG. Enough MPG increase to make it more economical using the chip and premium gas than no chip and using regular. Plus I get the performance as a bonus.

 

I also have a rough idle problem with my 2002.
I took it into the dealer and they hooked it up.
Naturally it isn't sending any codes so they can't do anything about it.
They told me that while driving at a steady rate of speed the computer leans out the engine to save gas. When you stop the engine is still running lean and that is why it doesn't idle right until the computer corrects it.
I never noticed my 2001 doing this and I think the whole story is a bunch of bunk.

 

canyonslicker what kind of gas milege you getting with that setup?

 

Man...I'm overwhelmed at how many people have already responded so quickly and kindly. Gas Milage...ha..I average 10mpg in town and have done as well as maybe 11. On the road, I've felt good about 17mph. I guess I thought it kind of odd to have to "change motor mounts" as they suggested; however, they seem to sound like they know what they are doing. Literally, it is probably on 250rpm fluctuation only at idle; however, I don't want it to have 50,000 miles, out of warranty and find out I'm super screw..ed.

Thanks!

 

Rough Idle Check this link out it may be what your loooking for.

https://www.f150online.com/forums/sh...*&pagenumber=1

 

16.5 mpg Hiway @ 75 mph avg. 14.8 mixed .

My worse was 12.1 mixed (same basic route). Hiway was 14.2 worse case.

My monetary savings are small.