Seriously? Rough Idle when WARM OUTSIDE? | Ford Explorer Forums - Serious Explorations

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Seriously? Rough Idle when WARM OUTSIDE?


December 31, 2012
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Year, Model & Trim Level
2001 Ford Explorer Sport
I'm having a rough idle that is made much worse when the temperature outside is higher than 35-40 degrees F. 2001 Explorer 4L SOHC


Temp outside is 30 F: car idles and accelerates perfectly from start up. After engine temp is warmed up to operating temp, at stop/idle there is a barely noticable, rare miss. I'm tempted to say in this situation it doesn't miss at all.

Temp outside is 45+ degrees: the car idles and accelerates fine at start up. Then as the engine reaches operating temp, the RPM's drop and the idle is quite rough (antenna and dash shaking, coins in cup holder jingling). It accelerates fine and there is no miss at speed, only when I am stopped or at idle (in Neutral, Park and Drive it is the exact same).

When it misses, there is no "searching" or fluxuating of RPM, it just dips barely below 500.

2001 Explorer Sport V6 4L SOHC
170,000 miles

Work done:
Replaced intake manifold gaskets
Plugs and wires ~4yrs old
Fuel filter ~3yrs
MAF and Throttle body cleaned a week ago
New O2 sensors

What the heck can be influenced by outside temp? Especially positively influenced by cold weather? I haven't noticed a preference to dry/wet conditions, I think its the same symptoms regardless.

Thanks in advance!