03 4.0L Explorer Rough Idle

[joefnh]

I have read several of the threads on rough idle and have attempted most of the possible fixes, so far nothing has worked. Here is what I have tried:

1.) Clean MAF with approved cleaner

2.) Ran 1 treatment of Seafoam (16 oz) through air intake vacuum hose near IAC. This should allow for even distribution to all cylinders.

3.) Cleaned IAC. Note: could not find felt filter pellet mentioned in another thread. This version of the IAC could not be opened to expose the filter. Is this a problem? Is the felt filter normally found on an 03 4.0L?

4.) Replaced plugs with Motocraft platinum.

5.) Ran 1 can (16oz) of Seafoam through the fuel system with a full tank of gas (87 octane)

6.) Changed oil / filter 5W-30 synthetic Mobil 1 Fram Xtreme Guard filter

7.) Replaced fuel filter (Fram)

8.) Replaced air filter (Fram)

9.) Checked for vacuum leaks, nothing found

So far nothing has helped. This engine has only 35K on it, any ideas on what might help??

--Joe

 

[302Xplorer]

When you changed you plugs did you do the wires as well?

 

[bippy93]

Check the harmonic balancer. It might have seperated at the rubber part.
We just had 1 the other day.

 

[joefnh]

No I did not replace the wires yet. At 35k would the factory wires be acting up?

As far as the harmonic balancer, I did have go out on my wifes Town & Country. But this seems like an actual firing / combustion issue since the RPM's do move slightly

 

[302Xplorer]

If they are defective they would. Check for arcing in a dark garage w/ the hood up and the truck running.

 

[ExplorerDMB]

Hard to say when and how many miles wires can begin to arch. I would still look into the IAC if I were you. Is it missing at all? Pull up the history codes on it and see how many times you've had a misfire and in which cylinder. To check for an arch, spray down the wires with some soap and water mix and see if you hear anything or see anything. If not, you may be ok, but it can still arch inside the boot part. Good luck.

-Drew