2005 Explorer 4.0 SOHC - Engine Shake at Idle

[Curtdh]

Good morning,

Over the last month 1/2 I have been dealing with the "rough engine/shake at idle" issue that many others on here have posted about. I bought this 2005 Explorer from my aunt after my uncle passed last October. It has 118,000 on it now. I want to layout what I have all done thus far and then see if anyone has any ideas moving forward to get this resolved.

1. Replaced Air Filter
2. Cleaned the MAF (also ran truck with it unplugged and the issue was there, just a little worse.
3. Cleaned the throttle body until it looked like a new one.
4. Plugs and wires
5. Fuel Filter

After all of these things (which had never been done so they all really needed to be done anyways) I was still having this issue. Then I found the post about having Ford flash the ECU with an update. Thinking this might fix it I went ahead and had that done. It did bring the idle up to around 700-740 (it was at 600-615 previously) it didn't fix the engine shake at idle, and actually made the shake even more noticeable.

6. Flash ECU

Finally I took the Ex to a very reputable shop that I have had alot of other work done at. They proceeded to diagnose the problem like I hadn't done anything yet. Once they got to the smoke test I admit I was hoping this would be where we figured it out, but they couldn't find any leaks anywhere, except from the EGR valve which they mentioned is somewhat normal, but he would continue checking. After looking at fuel trims and everything else (one of the banks was running a bit lean) he tested the EGR valve from the tool. He would slowly open it up 10% at a time at idle, watching to see if the value changed. It didn't change until 50%, which is where the engine really started to run rough. He was fairly confident that it was the EGR that was causing the issue, so much so that he said he wouldn't charge me for the 3 hour diagnosis if that didn't fix it. Well 2 days later I replaced the EGR valve and no change at all!

7. EGR Valve

So this brings me to where I am now. I have no idea where to go next and am sick of throwing parts at it (even though most of the items above needed to be done).

I am hoping someone on here can point me in the right direction to fix this issue!

Thanks,
Curt

 

[Mr. Truckles]

Mine does something pretty similar but I haven't really done anything about it. Did they check out the Idle air control at all?

 

[Curtdh]

This explorer is the "drive by wire" so it is all computer controlled, meaning nothing can be done with the IAC from what I have read. Someone please correct me if I am mistaken.

 

[turborich]

Good luck, it's a very common issue and even when everything is functioning 100% correctly the idle still is rougher then it should be. Mine isn't very bad, however I don't think it should have any noticeable miss/vibration at idle and it does. After much research and going through everything possible I have just learned to live with it. My neighbor up the road has a 2008 Explorer 4.0 and it runs, sounds, idles the exact same as mine. I will never consider anything powered by the 4.0 liter sohc engine in the future for several reasons. I have thought about having Ford flash the ECU with the newest software, but I've read that it's a crap shoot. Sometimes things get better and sometimes they can be made worse so I'm not going to have it done.

 

[Boogiejones]

Good luck, it's a very common issue and even when everything is functioning 100% correctly the idle still is rougher then it should be. Mine isn't very bad, however I don't think it should have any noticeable miss/vibration at idle and it does. After much research and going through everything possible I have just learned to live with it. My neighbor up the road has a 2008 Explorer 4.0 and it runs, sounds, idles the exact same as mine. I will never consider anything powered by the 4.0 liter sohc engine in the future for several reasons. I have thought about having Ford flash the ECU with the newest software, but I've read that it's a crap shoot. Sometimes things get better and sometimes they can be made worse so I'm not going to have it done.

Hi. Good comment. Thanks. How long did the car run for after this post? I'm thinking about buying a used explorer with this issue and wouldn't mind just living with the idle problem. Thanks again.

 

[Fix4Dirt]

just a note, that poster hasnt been on the forum for 4 years, so chances are you wont hear back.... however, i notice on my SOHC the idle is rougher than with other vehicles, and ive had no apparent issues arise because of that (at 320k at the moment)

 

[J_C]

This explorer is the "drive by wire" so it is all computer controlled, meaning nothing can be done with the IAC from what I have read. Someone please correct me if I am mistaken.

You are mistaken. IAC gets dirty, and it wears. Cleaning helps if not worn too much. Putting a drop of oil on the bushing inside helps reduce wear and promote smooth operation again.

Some other things to check in no particular order (if it is only rough at idle... then we can ignore things like fuel pressure which only makes it worse at higher load). Scan tool, long term fuel trims, codes, especially misfires. Also check the temperature sensor, if the output looks right for the situation.

If you've been burning oil, exhaust pressure, suspecting clogged cat(s).

Stiff bearing on a belt driven component. Take belts off, turn them by hand, or notice whether the poor idle does away running a SHORT time like that (so you don't drain the battery without the alternator powering the system).

Plug and wires, of course this is a routine thing to replace and could contribute to cylinder misfires, as could poor quality fuel or clogged injector(s).

It's been a long day and I'm tired so I'm sure I've missed a few common/potential things it could be, from the two bulk connectors under the hood, vac leak (including intake manifold gasket as a common source but really anywhere when the vac lines get this old), maybe even a jumped timing chain.

I wouldn't just "live with the idle problem" because as other parts degrade a bit, you are left with less margin, less warning when something else goes wrong, before you are stranded and needing a tow.

When considering buying one, a reasonable owner should at least let you hook up a scan tool. If they aren't comfortable with even that, or your doing more and you can't pinpoint the cause before buying, I'd seriously consider paying a shop to do a pre-purchase inspection hoping for a diagnosis of the rough idle. Walk away if the owner won't even let you do that much. Guess it also depends how much the owner is willing to knock off the selling price due to this... crazy times today, where vehicle valuations are skewed higher than they'd normally be.

Anyway, not sure why there was focus on this unresolved topic where there's bound to be plenty of other topics where a rough idle was solved.

 

[Lee's Automotive]

just a note, that poster hasnt been on the forum for 4 years, so chances are you wont hear back.... however, i notice on my SOHC the idle is rougher than with other vehicles, and ive had no apparent issues arise because of that (at 320k at the moment)

Yep mine does the same at idle can you feel it in the steering wheel?

 

[Fix4Dirt]

Yep mine does the same at idle can you feel it in the steering wheel?

no not really, i can see the engine haha motor. mounts still good it appears, since in drive reverse it doesnt move much, just vibrates

 

[Lee's Automotive]

no not really, i can see the engine haha motor. mounts still good it appears, since in drive reverse it doesnt move much, just vibrates

whew good same as mine

 

[Fix4Dirt]

whew good same as mine

if i put a glass of water on it itll fall after a bit though lol

 

[Lee's Automotive]

if i put a glass of water on it itll fall after a bit though lol

Same

 

[Tekreck]

Run some fuel injector cleaner in your next couple of tanks.

 

[Lee's Automotive]

Run some fuel injector cleaner in your next couple of tanks.

ive done techron and 3 cans of b12

 

[Fix4Dirt]

ive done techron and 3 cans of b12

b12 where it at also i will say i have a 4wd with deleted balmcenshaft so inexpect more vibration from it

 

[Lee's Automotive]

b12 where it at also i will say i have a 4wd with deleted balmcenshaft so inexpect more vibration from it

Amazon product ASIN B000CCMNAG

 

[Fix4Dirt]

Amazon product ASIN B000CCMNAG

haha yeah i meant b12 is where its at lol but ye indeed

 

[Lee's Automotive]

haha yeah i meant b12 is where its at lol but ye indeed

Yep 3 cans at a quarter of a tank and let er rip is what i did