Explorer idling rough

[05explorerXLT]

I have an 05 xlt that started having a rough loping idling. It runs smooth for a second and then runs rough for a second. It did the same thing 10 months ago so I had the plugs changed, new plug wires, air filter, fuel filter and it ran smooth but now it is back. Why would this symptom come back. Any ideas?

 

[LJ4174]

Hmmmm... Mine does this too... 2005 XLT 4.0 engine, with 54,000 miles, has done it for a while...

 

[05explorerXLT]

Mine has 60,000 miles on it.

 

[05explorerXLT]

Anyone? I heard that the only fix known is to have the ECM re-programmed with a new file from Ford and even that does not eliminate the rough idle 100%.

 

[RickM]

I assume you have the six....

 

[wlbrz]

my 03 does it to sometimes and i can not find it. i am thinking a small vacum leak but have sprayed everything but can`t find it.

 

[imp]

Electronic, or Mechanical Problem?

For some reason, it seems most every problem is addressed as computer-related nowadays. A rough idle can be caused by mechanical problems within the engine itself, such as a burnt valve, bad plug, etc.

It is possible to individually check each cylinder, while the engine is running at idle, or slightly off-idle, by "forcing off" the injectors, one by one, and observing any change in speed or run quality. This can single out a bad cylinder more surely than a compression test usually does. (It can also reveal that an injector is partially clogged, another issue!).

No matter how complex the electronic controls becomes, the engine still remains a mechanical device prone to all the old failure possibilities....imp

 

[wlbrz]

over the winter i could here a vacume whistling noise from the engine but i never found it.

 

[RickM]

over the winter i could here a vacume whistling noise from the engine but i never found it.

6 or 8?

 

[wlbrz]

4.0 6 cyl

 

[snickstx]

My 4.0 has been rough since brand new. Dealer flashed it under warranty but that didn't do anything. However, that was before the last software was released. On my list but not very high due to $$$. It really should be a no charge item.

 

[oneeyemike]

I just had mine re-flashed last week trying to solve a rough idle and a gas mileage problem after replacing a TPS. Helped idle somewhat but my mileage keeps dropping. When the TPS was throwing codes I was getting around 19mpg with no idle issues. Now, new TPS , no codes but mileage is down to 16.5. What kind of MPG are you guys with the rough idle getting?

05 xlt 4.0 86,000