lsprz

Hello all - I have a 5.4L engine, I've been having a rough idle lately. It feels like stalling when I'm in park, or at a stop. It seems fine when I'm in motion, driving. It's an intermitting problem, there are days it drives normally. I don't have a check engine light on. I changed air filter and fuel filter, but no help. What's next? Oxygen sensor? Spark plugs? Thanks for your help.

Bert

Clean the MAF with MAF cleaner and see what it does. The light doesn't have to be on for it to set a code. Autozone will check for free.

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Bert

lsprz

Thanks for the idea. I cleaned the MAF with MAF cleaner. The engine condition is the same. I would still appreciate some additional assistance. Thanks.

Bert

Did you get any codes?

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Bert

4cylnutmk1

Like sort of a rumble when stationary? Ive seen this before was a dirty spark plug, so I would check them next.

hurk

Just a couple of ideas... I'd clean or replace the idle air control valve (IAC).
After that & since it's intermittent, I'd suspect a coil, but you'd need a misfire code or something to figure out which one. I've read numerous topics on the various Ford forums concerning intermittent power loss & hesitation problems being solved by replacing a coil or coil pack. Similarly, idle problems are often times reported to have been related to the IAC which has a tendency to get clogged & gummed up w carbon n stuff.

lsprz

I went to Autozone, and had the codes read.
P1131 - Ford - Definition; Lack of bank 1 O2 transitions
Explanation; ECM detected bank 1 O2 at its lean limit
P1151 - Ford - Definition; Lack of O2 switches-bank 2 sensor 1
Explanation; ECM could not adjust fuel trim because of a lean or rich condition.
P0174 - Domestic - Definition; Fuel trim bank two condition
Explanation; The ECM has detected a rich or lean Air/Fuel ration condition on engine bank two.
P0171 - Domestic - Definition; Fuel trim bank one condition
Explanation; The computer has recognized a rich or lean condition on one engine bank only

Bert

Those probably indicate a vacuum leak or as hurk mentioned, clean the IAC and see if it helps. There could be a vacuum hose off somewhere too.

OBD-II Trouble Code: P0171 System Too Lean (Bank 1)
OBD-II Trouble Code: P0174 System Too Lean (Bank 2)
OBD Trouble Code: P1151 Lack of HO2S-21 Switch, Sensor Indicates Lean

P1131 is similar to P1151.

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Bert

lsprz

Ok people, first off thanks for the help. The problem became less intermittent, and now it think it's completely gone. I'm waiting for more time to pass to be sure, will keep checking for codes.
This is what I've done. I bought some spark plugs and changed out the four on the passenger side. The third and fouth ones had had a bit of oil on them. That worried me, but I read that that may happen if too much oil is added on an oil change. I had my oil changed at walmart last, it doesn't suprise me that they'd over fill while rushing.
I then bought a cleaner for the IAC valve, which is the same cleaner for the throttle body, and cleaned out the valve and the throttle body. After putting things back together, things have been feeling, sounding, running great.
I still need to change out the other four spark plugs on the driver side, and hope not to find oil on any of them. I am also going to do an oil change myself.
This may sound dumb, but why is it that even though my engine calls for 5w-20, because of it having alot of miles, people suggest an oil thats 5w-30/40/50?

Bert

Ford recommended 5w20 for better mileage. If you're using oil, you could go to 5w30 but I'd stick with what it calls for.

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Bert