2002 Ford Explorer stalling at idle.

[NYEngineer]

My sister in law has a 2002 Explorer. It's a V6. She said it runs fine as long as she isn't idling. When at idle, it studders and shakes and sometimes stalls, but the instant it gets moving, it's fine. Her local mechanic has changed the plugs and fuel filter and whatnot. There is no CEL. I live in another state, so I can't just go look at it. Any ideas?

 

[Jason2007]

Check the idle air bypass valve.

 

[punisher]

Pull codes anyway even if the light is not on.

Changing plugs and fuel filter for an idle roughness concern is stupid (bad mechanic, bad mechanic).

Idle problems on those I look for vac leaks,small EGR leaks etc. Either one of those should set some sort of code.

You really don't see engine roughness/idle concerns without at least a missfire code.

 

[GearJammer]

My wife's Explorer was doing something similar and a cleaning of the idle air control fixed the problem. Just remember to disconnect the battery.

 

[mechtech2]

First, all vacuum lines and their connections should be checked and repaired. Double check the PCV system - ALL of it. Manifold and intake leaks should be fixed, as well. Also, the brake booster system is an overlooked cause of vacuum leaks.
CLean the TB bore and plate really well.
Then the idle air motor, if necessary.

 

[NYEngineer]

Thanks for the replies. There are no codes. I relayed the message. I'll let you know how it turns out.