Sorry, I know there are a lot of these threads. I have a 02 3.0 with almost 112k on the clock. She is rough at idle, especially when cold. When accelerating though, the engine is smooth. I recently purchased it and it has another 2k to for an oil change on the sticker, so my first thought is plugs and wires. Any other suggestions?

 

If there was any problem you would get a check engine light.

 

Yeah, I'm not losing any sleep over the rough idle, and it goes down a little after its warmed up. I checked the wires and they looked pretty new, so I skipped doing them and the plugs. The fueld filter was less than fun to replace, but it didn't seem to help any. Next is the MAF and maybe the intake. Thanks for input!

 

let the engine warm up to operating temp and let it idle for a while and see if the check engine light comes on or flashes. if it flashes its indicating a misfire. so if it does that, id start with the plugs, wires, test the coil pack, etc. if none of that is the problem, check the egr, the iac and the tps. if not those, run a vaccuum test on the motor and see if it has a vaccuum leak anywheres.

 

ok i just checked on my 02, there is NO egr valve, yet oreillys sells one (wtf) the next thing im checking is the TPS, since i unplugged it and the idle did not change at all (not sure if it is suppossed to or not yet)

 

Figure this out yet? I'm having the same issue. Rough Idle,and slightly increased idle speed most of the time. No check engine light(or codes). Was hoping it was the IACV, but that seems to be functioning properly. Guess i need to go over all the vac lines. I hate these hard plastic lines.

 

I battled the same issue for months. The truck ran so good the idle issue seemed to stand out. I was told by two dealerships that is to be expected from a 3.0l. They all idle somewhat rough. Some more than others. I have had mine diagnosed three times and each time there was nothing wrong with the engine. They went so far as to tell me actually how well it ran.

It is a little unnerving for an **** owner like me, but seems like I will just have to get used to it.

Now I am investigating a minor oil consumption issue. 1 qt every 3000 - 3200 miles.

 

I am having a similar problem, since i got the truck it has idled a little rough. lately I have been getting a check engin code. It says misfire on cylinder #6. there was also a code that was misfire on #5 also. I replaced the plugs, wires, and coil pack. now there is now the #5 misfire but the #6 misfire keeps comming on. does anyone have any ideas what it could be?

 

WRONG. if your plugs start going you dont get a cel... your airfilter is cloged no cel. wires go bad no cel.

hell it took my 02 months to pick up that it was running lean...

 

it could be a clogged injector

 

i took my 02 to the dealership i ork at yesterday and the master took a look at mine and said its idling rough cause the cam syncro jumped a tooth, and thats causing it to idle rough and the oil gauge to be jumpy at low idle (4000-6000 RPM)

 

I being a ford tech and owning a 97 ranger w/3.0 I can say without a doubt that alot of you guys with 100k on your odometers are probably in need of a head job. There is even a ford TSB in regards to the exhaust valve seats cracking and causing the valves not to seal . Which in turn will of course make it run weird at idle but higher revs you wont notice it as much . I myself just did the heads on my ranger at 145k . And without a doubt you could see that my exhaust valves where recessed in the head about 1/8" or more . Now after having new seats installed in my heads the truck idles beautifully and I even have to double check that it is running at stop light it idle so well. I know some of you dont wont to hear this but it is very common and the dealership I work at we have probably done 1/2 a dozen rangers in the last year , and all have never been back for any issues so far .

 

what i was thinkin about doin is gettin some heads out of a junkyard and takin em to the head shop and gettin em magnafluxed, ported, and shaved down a little and just swappin em and rebuilding the stock ones as a spare....would that be a good idea?

 

You could also go on ebay and get a set of head from dover cyclinder heads . They send you a complete set of heads with no cores all ready to go including shipping for around $200 . And I can personaly say I had a friend buy a set and they worked out great for him .

 

I havehad the same rough idle problem for some time now, changed the plugs and wires, new fuel filter, oil changes, injector cleaner etc... all had no impact on the rough idle and blinking engine light. If anything it got worse. I finally took it in and the mechanic said that I need new heads because the vlave seals are out and I have low compression in 3 cylinders and the stock 3.0 heads are junk. Ford now makes improved heads for 3.0 rangers. Best advice is to take them off yourself and get a head job. Probably a couple hundred and a big head ache but its better than blowing the engine

 

First of all valve seals won't lower your compression but valve seats will. And if you take them to a good machine shop they install new seats and there as good as new . Also to the best of my knowledge the heads all years have the same problem but supposedly the newer heads breath a little better. If you decide to pull your heads you will see the exhaust valves will have sunk in and most likely cracks in the seat .