Slightly rough, low idle

[Iniquity]

I picked up my Focus (2001 SE, 2.0L Zetec, AT) nearly two weeks ago. The idle is a bit "rough", i.e. there's a vibration in the engine compartment akin to a clothes washer. Nothing horrible, but it seems to idle a bit low. It looks to be about 600-700 rpm idle. Is this normal, or should I check the MAF out and/or possibly replace some spark plugs? It's been a while since I had a Ford of any type, let alone one this new. (It's been a LONG while... last one I had was a 88 Tempo. Don't laugh.) Thanks in advance. I just want to get her running nice and smooth before I do anything to her. (I even ordered an Actron CP9135 OBD-II scanner for her )

[TXFO]

you probablly just need motor mounts. look over the PCV system for a torn elbow. very common vac leak source on ALL Fords and will cause a poor idle quality.

[Iniquity]

I know of the one on/near the PCV valve, is there any other I should look for specifically? I haven't had a chance to check the motor mounts just yet, but I have two days off now so I get some time to pamper my car.

EDIT: I forgot to mention... it's kind of odd, but it seems like my lights (inside and headlights) flicker ever so slightly when I'm idling. If I weren't anal retentive about my car, I'd probably have never noticed it. And yes, I am on my laptop in my car checking this right now.

[Iniquity]

Okay, I found why the outside lights were flickering. Some genius didn't clip the lamp in properly. When I examined it, I have a lovely melted spot in my passenger side headlight housing. Awesome.

I haven't checked the inside lights just yet, as it's not dark enough.

I did change out the lovely air filter with a simple STP which I'll replace in short order, as I'd like to move to a CAI... but maintenance comes first.
The idle seems to have smoothed out a tiny bit...
I've also got some Bosch Platinum+2's I'm going to be putting in, as soon as I clean the valve cover off a little bit. Something doesn't sit well with the idea of junk going into places it shouldn't. Time to pull out the old toothbrush. I also got a Fram oil filter, as I'm fairly certain that the current one hasn't been changing in like 5 or maybe 6... years. The person that owned the car before me was more or less just a bit careless. I mean... who puts a window switch in upside down?! I digress... If the ride smooths out some more with an oil/filter change, and new plugs, then I'll know what's up. I'll post pics of my MAF soon, but it looked nice and clean. Almost as if it had been replaced recently. Weird.

[carlingskie]

thats sad.. im guessing there's tons of sludge in the engine.. =(

[Iniquity]

From what I can see from just pulling the dipstick, the oil in there is clean... but that doesn't say much about sediment other than that it's not suspended in the oil. I'm going to change the oil out tomorrow, since I:
1) Don't know what's in it. They could have put 10w30 in there for all I know.
2) Assume the oil filter is probably ancient, and at best a "value" filter.
3) Don't know when the oil or filter were last changed.

I'd rather be safe than sorry.
With the new plugs, filter and oil in place I should get at least a better idle. I also moved to 89 octane, instead of 87. I'm not sure if that's good, bad, or moot... but I've always noticed a smoother running engine when I run with 89. I swapped out the air filter as well, since it was looking a little "weathered".

On the flip side, it looks like my idle went up a little. I got a chance to take a more accurate reading of the tach today, both before and after the changes, and it looks like I gained about 30-50 rpm, bringing me to what appears to be just under 700 rpm idle. After the plug change out I'll get a chance to relearn the idle, so that may fix more than anything so far.

[Iniquity]

Okay... work has been eating EVERY moment of my free time... BUT!
I found that the idle gets rougher, and the lights begin to flicker when I put more electrical load on. Like... turning on my headlights...
It's really weird. I'm hoping it's not the alternator... any ideas?

[jessterZX3]

hey glad to hear things are getting better for you. See your in plam bay, me too. Gonna have to hook up sometime, were putting together a meet maybe next weekend at longdoggers.

[bigdaddyG8]

I'm having the same issue with the lights and idle, particularly under load.

My suspicion is the alternator, but I have yet to get to it.

Let me know what you find out.

[Iniquity]

I got my OBDII scanner today, ran a scan on the car and it came back all clear... so I can't imagine it's anything with the electrical system itself... Perhaps the alternator really is going out. If it's something like a bearing in the alternator putting undue stress on the engine, that may cause it to be idling a little low, and thus rough. Above 800 it purrs... it's just when it gets below 800 it starts run a little rougher. Is it possible that more electrical load could cause the alternator to run "harder"?

[Mjasinski]

what kind of scanner did you get? Sorry to pull this off topic i just wondered... but my yellow zx3 does the same thing, i need to fix a bunch of stuff but its colds here and i really don't want to touch tools and get instant frost bite

[Iniquity]

I got the Actron CP9135. http://www.amazon.com/exec/obidos/AS...m-20/ref=nosim
It's a really nice little scanner, though the warning label on the cord worries me.
It says "This cable contains lead, wash your hands after using this device." haha
Either way, it's a handy little tool. I will be changing out the plugs and oil the day after tomorrow, rain permitting... So we'll see if that actually fixes the problem.
I would have done it Sunday, but I had to be a witness for a car accident.

[bigdaddyG8]

I have checked that connector before, and it was fine... maybe I'll double check.

Thanks for the link for the OP though.