Low Idle RPMs- Ford SOHC 4.0 L, Year 2000

In my Explorer 2000 that has a 4.0L SOHC engine, the idle RPMs are about 550 while they are supposed to be 800, at these low RPMs the idle is rough. there is
no other problem, does not stall, shifts normally, has adequate power, yields about 17mpg on highway. I have checked several times over the last 6 months for any codes, there is never any.
When the engine is started from cold, for a couple of minutes the RPMS are about 1000, then as the engine warms up a little the idle RPMs drop to 500-550 and stay there.
The engine has a new IAC, intake manifold gasket and air filter. Also had a new camshaft chain tensioner installed.
The Dealer/Stealer cannot find anything wrong.
Any Ideas ?
Thanks in advance.
Matt Remove asterisk to email, add "Re:" (without quotes) to subject line.
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just tell the damn dealer that the idle is too slow and get a technician to speed it up...and if it's something electronic it might possibly be covered under your smog control warranty....(usually exceeds the common 3/36 they gave ya when they sold ya the car) cause a slow rough idle will undoubdtly effect emmission readings making the car unable to pass pollution control specifications....

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On Fri, 23 Apr 2004 13:43:12 -0400, Admin

If you are not over 50K miles, the emissions warranty should take care of it. If it is idling slow, the emissions are not likely to be within spec. They are required to ensure that it will pass an applicable emissions test. The idle speed has a very definite specification that it should meet. That said, it may simply be something is incredibly gummed up in which case they are going to charge you for a maintenance procedure. If the problem is electronic or mechanical emissions related, they have to take care of it.
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as an after thought if your in california the emmission warrenty covers things like computer, fuel injectors, catalytic convertors and some other surprising components clear up to 100,000...well in excess of the "manufacturers warranty" it's mandated by the state and in some cases Fed's....drag out your owners manual, document all diagnostic charges because once you pay for a faulty diagnosis you didn't get what you paid for and any reputable shop should stick with the diagnosis for free till they find the problem and if it's a dealer...just ask to speak to the district rep and show him the paper trail.....
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wrote:
'as an after thought if your in california the emmission warrenty covers 'things like computer, fuel injectors, catalytic convertors and some other 'surprising components clear up to 100,000...well in excess of the '"manufacturers warranty" it's mandated by the state and in some cases 'Fed's....drag out your owners manual, document all diagnostic charges 'because once you pay for a faulty diagnosis you didn't get what you paid for 'and any reputable shop should stick with the diagnosis for free till they 'find the problem and if it's a dealer...just ask to speak to the district 'rep and show him the paper trail..... '
' ----------------------------------------------------------------------------------------------
Thanks for your suggestions. Here is some additional info.
I am in PA, I am subject to emissions inspection via OBD method, there are no fault codes of any kind in the memory, check engine light has never been on.
Somebody has suggested to me that the engine needs an 'update to engine management software' , Ford itself has no TSB about the need for software update for this engine.
I called the Dealer today, the service manager says that he will have to hook up the vehicle to their WDS system to see if there is any update available and that I will have to pay for update procedure like this.
Any thoughts about the likelihood of success by an update like this, any ideas about a fair price of such update procedure ?
Thanks
Matt Remove asterisk to email, add "Re:" (without quotes) to subject line.
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How are you measuring your RPM? Is the engine hot? In gear or out? Are you using a proper tachometer ( .5% or less accuracy )or the vehicle tachometer ( which is not real accurate ). Vehicle specifications are 670-750, meaning your measurement with a inaccurate measuring device could be off enough that the number you are reading says you are out of specification yet it is really in proper range. That would be a good reason why you have no codes, as far as the processor is concerned the idle is correct. At that point maybe you need to look else where for the rough idle concern. The first step is to compare it to a like vehicle, same year, same basic equipment and mileage. I'm betting it will have no noticeable difference from one to the other.

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Tom thanks for your reply, here is the info:
I am reading the RPM from vehicle tachometer, (I said 500 because the dial hand is barely above the 500 mark and sometimes it is even just at the 500 mark) this reading is from a hot engine in idling state, the RPM stay almost the same in hot idling state regardless of vehicle being in gear or not and/or the Climate control is on or not. The vehicle has about 55K miles on it, maintenance wise it is a very well kept vehicle.
According to the dealer, there is no detectable abnormality in any test they ran on it to look for a reason of rough idle. There have been complaints about this engine having rough idle and back firing which in many vehicles were fixed by replacement of intake manifold gasket and camshaft chain tensioner, these procedures actually worsened the roughness of idle on my vehicle instead of improving it, the degradation is only mild though.
Do you think 'engine management software' update could be a possible solution, the dealer says he is aware of at least one such identical engine that was having low idle RPM and was even stalling and it improved with such procedure since there was a calibration update needed for it.
Thanks again,
Matt
==================================================
'How are you measuring your RPM? Is the engine hot? In gear or out? Are you using 'a proper tachometer ( .5% or less accuracy )or the vehicle tachometer ( which is 'not real accurate ). Vehicle specifications are 670-750, meaning your 'measurement with a inaccurate measuring device could be off enough that the 'number you are reading says you are out of specification yet it is really in 'proper range. That would be a good reason why you have no codes, as far as the 'processor is concerned the idle is correct. At that point maybe you need to look 'else where for the rough idle concern. The first step is to compare it to a like 'vehicle, same year, same basic equipment and mileage. I'm betting it will have 'no noticeable difference from one to the other. ' '
' '> In my Explorer 2000 that has a 4.0L SOHC engine, the idle RPMs are about 550 '> while they are supposed to be 800, at these low RPMs the idle is rough. there 'is '> no other problem, does not stall, shifts normally, has adequate power, yields '> about 17mpg on highway. I have checked several times over the last 6 months 'for '> any codes, there is never any. '> '> When the engine is started from cold, for a couple of minutes the RPMS are 'about '> 1000, then as the engine warms up a little the idle RPMs drop to 500-550 and '> stay there. '> '> The engine has a new IAC, intake manifold gasket and air filter. Also had a 'new '> camshaft chain tensioner installed. '> '> The Dealer/Stealer cannot find anything wrong. '> '> Any Ideas ? '> '> Thanks in advance. '> '> Matt '> Remove asterisk to email, add "Re:" (without quotes) to subject line. '
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Tom thanks again for the response.
I understand your point, there is no doubt about human perception being very imprecise, if we go by just the perception then our cars run better after washing and waxing alone.
This is how I say the idle roughness increased after camshaft chain tensioner and intake manifold gasket installation. Before this procedure I would feel a ripple in drivers seat and steering wheel only when the compressor would cycle on/off, now I feel this ripple even without compressor on/off, may be every thirty second or so, but there is no discernable pattern to the frequency of this ripple.
I realize that if the issue is mechanical, software update is not going to fix it. I actually inquired of the dealer if he could just tell me what version of the software is onboard and what is the latest version available from Ford at this point so I could figure out if there is any update available at all. I was told the procedure is to hook up the vehicle to WDS, it will interrogate the onboard system and compare it to the latest version available and if there is an update it would install it and I would have to pay for the procedure, update or no update.
My thought is that if there is an available update, it means the onboard system was deficient to begin with thereby requiring the update, so it is the responsibility of Ford to pay for it. I am UNaware of what industry standard is about such updates, since I am not in this business nor have I been in a similar situation before. I am comparing it to Windows, Bill Gates puts out updates all the time, we do not pay him specifically for that, I know that in case of Windows Bill Gates does not have to arrange for any labor as for as updating my particular machine is concerned.
Matt ===========================================
'
' wrote: '> '> Tom thanks for your reply, here is the info: '> '> I am reading the RPM from vehicle tachometer, (I said 500 because the dial 'hand '> is barely above the 500 mark and sometimes it is even just at the 500 mark) ' 'I pretty much thought that you are using the vehicle tach, I have seen up to a '100 rpm difference from a vehicle tach to a good diagnostic tachometer. ' '> this '> reading is from a hot engine in idling state, the RPM stay almost the same in '> hot idling state regardless of vehicle being in gear or not and/or the Climate '> control is on or not. The vehicle has about 55K miles on it, maintenance wise 'it '> is a very well kept vehicle. '> '> According to the dealer, there is no detectable abnormality in any test they 'ran '> on it to look for a reason of rough idle. There have been complaints about 'this '> engine having rough idle and back firing which in many vehicles were fixed by '> replacement of intake manifold gasket and camshaft chain tensioner, these '> procedures actually worsened the roughness of idle on my vehicle instead of '> improving it, the degradation is only mild though. '> ' 'You are correct in that this engine has been known to have a somewhat rough 'idle. If the problem is actually worse than the norm, or if it is really worse 'from the repair the technician could have done something wrong. It is also a 'possibility there is nothing wrong but is only a perception you have that there 'is something wrong. By having the "problem" fixed you were expecting that the 'idle quality would improve which it may not have but stayed the same. I'm kind 'of trying to say in a nice way that the problem may not have been a problem and 'nothing was actually fixed. Because something was done to the engine and no 'physical change was made in your mind it is now worse. That is why your vehicles 'idle quality needs to be compared to another vehicle. ' ' ' '> Do you think 'engine management software' update could be a possible solution, ' 'If there is actually a problem with the software, yes it is possible. If there 'is a mechanical problem or no real problem, no. ' '> the dealer says he is aware of at least one such identical engine that was '> having low idle RPM and was even stalling and it improved with such procedure '> since there was a calibration update needed for it. '> '> Thanks again, '> '> Matt '> '> ==================================================
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wrote:

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Tom,
Thanks for the insight, we had a lively discussion.
By way of logic and reason I agree that there has to be a cut off point where manufacturer of any product should cease to be responsible for it. We all unwittingly demand perfection of others, so did I in this matter and I erred.
Actually what I had in my mind was that manufacturers of various products churn out half-baked products and use their customers as their beta testers which is a deceptive business technique, but I agree that not all variables of the future can be accounted for at the get go.
You are right, it is my vehicle I should take responsibility for it.
Matt
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
' wrote: '> '> Tom thanks again for the response. '> '> I understand your point, there is no doubt about human perception being very '> imprecise, if we go by just the perception then our cars run better after '> washing and waxing alone. ' 'There is a lot of truth in that, there's been many a time I've caught my self in 'just that scenario. Pilots will tell you they hear noises or feel vibrations in 'the air craft they are flying when over water at night, when in fact there is no 'vibration it is all in the head. It is a very real state of mind. '> '> This is how I say the idle roughness increased after camshaft chain tensioner '> and intake manifold gasket installation. Before this procedure I would feel a '> ripple in drivers seat and steering wheel only when the compressor would cycle '> on/off, now I feel this ripple even without compressor on/off, may be every '> thirty second or so, but there is no discernable pattern to the frequency of '> this ripple. '> '> I realize that if the issue is mechanical, software update is not going to fix '> it. I actually inquired of the dealer if he could just tell me what version 'of '> the software is onboard and what is the latest version available from Ford at '> this point so I could figure out if there is any update available at all. I 'was '> told the procedure is to hook up the vehicle to WDS, it will interrogate the '> onboard system and compare it to the latest version available and if there is 'an '> update it would install it and I would have to pay for the procedure, update 'or '> no update. '> '> My thought is that if there is an available update, it means the onboard 'system '> was deficient to begin with thereby requiring the update, so it is the '> responsibility of Ford to pay for it. ' 'Well yes and no. At the time the software was developed it may have been the 'best it could be. Does that constitute a deficiency? No I do not believe it 'does. There are a number of things a engineer can not possibly or properly 'predict in how software will work on a machine nearly 5 years after it was put 'together. The other factors are the machine is now out of the manufactures 'control. Just how long after warranty do you expect a manufacturer to pay for 'services? If a "deficiency" is found two years after a legal and binding 'contract is up you say the manufacture ought to pay for the "repair"? At that 'pint what is the warranty contract for? It sounds like you want a "life time" 'warranty. You bought the vehicle, now the manufacture is liable to you for life? ' '> I am UNaware of what industry standard is '> about such updates, since I am not in this business nor have I been in a 'similar '> situation before. I am comparing it to Windows, Bill Gates puts out updates 'all '> the time, we do not pay him specifically for that, I know that in case of '> Windows Bill Gates does not have to arrange for any labor as for as updating 'my '> particular machine is concerned. '> '> Matt ' ' Look at Windows for an example. Each version is in a number of ways better than 'the last, but just because you have....... lets say 3.0, does that mean that 'Microsoft should just give you 98 or XP? Yes you can download updates, but there 'is not a infinite amount of time that a version is supported. ' ' '> ============================================
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On Sat, 24 Apr 2004 10:48:37 -0400, "Thomas Moats"

Rough idle can be a little subjective. My dad's benchmark was his '53 Packard Straight 8 that would idle all day with a glass of water on the head without causing a single ripple unless someone slammed a door real hard.

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Yeah, it takes a hell of a lot to vibrate that much steel though. :)
wrote:> Rough idle can be a little subjective. My dad's benchmark

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The more the cylinders the less the vibration, simple fact. Two cylinders vibrate, four vibrate less, and so on. Also inline engines tend to vibrate less than V designs.
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my neighbor's explorer satred doing that. turned out to be the Idle Air Control on the throttle body. took it off and use carb cleaner to get rid of the carbon buildup on the tip and then reinstalled it. that was a year ago and the car was only 2 years old at the time. still runs fine

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