I have a 2007 Ford F150 5.4 L V8 started idling rough and knocking changed both VCT solenoids changed oil and filter still running roughly occasionally at idle?
What is your question?
Only does it when engine is warm at the top of a hill, or at a stop sign at idle, change, both the VCT solenoids and oil and filter, and it is still running rough at idle when I come to a stop no codes coming up since changing VCT solenoids
What makes this problem better or worse?
Only does it when it warms up at idle
How long has your 2007 Ford F-150 had this problem?
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Hi, this is Bo, an auto expert on RepairPal's Car Genius team!
Sounds like you've already replaced the VCT solenoids and done some basic maintenance, but that rough idle issue could still be tied to how the engine’s running once it warms up. Since it only happens at idle, I'd bet something's going on with the fuel or air delivery systems when the engine’s at a low RPM. Sometimes, a small vacuum leak or a failing ignition component can create issues that only show up when the engine isn’t under much load. You might want to double-check the vacuum hoses, the condition of the spark plugs, and even the fuel injectors—sometimes they clog up or stop working as they should.
That rough idle could also point to the idle air control valve, which controls how much air the engine gets at idle speeds. If that’s malfunctioning, it can cause your engine to run a bit rough when it's just sitting there.
Since you've already replaced a few things, it might be worth running through the ignition system and checking for any vacuum leaks or air/fuel delivery issues. I’m sure you’ll get it sorted out soon!
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