98 Expedition , rough idle
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98 Expedition , rough idle
Hello All,
I am new here, here it goes. My 4.6L 98 Expedition 70Kmi.
has developed a rough idle. Stopped and idle or light
cruise or on acceleration. No error lights on dash.
I purchased the manual and now I am totally confused.
The Tune up directions say the plugs last about 20-30Kmi and
the ownwers maintanace book says 100Kmi.
Am I even on the right track ? Is it the injectors ? The
infamous computer black box?
Help!
I am new here, here it goes. My 4.6L 98 Expedition 70Kmi.
has developed a rough idle. Stopped and idle or light
cruise or on acceleration. No error lights on dash.
I purchased the manual and now I am totally confused.
The Tune up directions say the plugs last about 20-30Kmi and
the ownwers maintanace book says 100Kmi.
Am I even on the right track ? Is it the injectors ? The
infamous computer black box?
Help!
Logistics Pro
Joined: Oct 2000
Posts: 3,960
Likes: 5
From: All over Texas
98 Expedition , rough idle
Could be a bunch of different problems. Some common items to check are plugs, wires, and/or fuel filter. It could even be bad gas.
The plugs are intended to last 100K miles, but not necessarily the case. If it were my vehicle, I'd replace the fuel filter first ($10) and then proceed to the plugs and wires.
Good Luck.
The plugs are intended to last 100K miles, but not necessarily the case. If it were my vehicle, I'd replace the fuel filter first ($10) and then proceed to the plugs and wires.
Good Luck.
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98 Expedition , rough idle
Thanks Buzaard for your reply ! A couple of Q's : 1) does the check engine light only come on whe a code is stored , or can a code be stored without the chech engine light beig on.
2) What's the best code reader for all vehicles or is their such a device ?
2) What's the best code reader for all vehicles or is their such a device ?
Logistics Pro
Joined: Oct 2000
Posts: 3,960
Likes: 5
From: All over Texas
98 Expedition , rough idle
I've believe that a code could be stored without a light on. I've never (knocks on wood) had a stored code. As far as the best code diagnostic tool, I don't have a clue, but I suppose the equipment at Ford dealerships is the best AND most costly. I've got the Superchip tuner that also reads codes. Do a "Google" search of OBDII. I've heard that Autotap is a great product.
Tuned
Joined: Aug 2002
Posts: 291
Likes: 2
98 Expedition , rough idle
I hope this thread can give you some hint:
https://www.ford-trucks.com/forums/s...hreadid=125499
It's a very easy check.
Good luck!
https://www.ford-trucks.com/forums/s...hreadid=125499
It's a very easy check.
Good luck!
Junior User
Joined: Dec 2002
Posts: 73
Likes: 0
From: Baltimore, MD
98 Expedition , rough idle
I read the string you mentioned a while back, WhyFord. Never thought I would need it, but then I never thought I would blow a spark plug out of my head either. My expe started doing this yesterday. Sure enough, that back 90 degree boot was torn. How the he!! did you guys get your hands back there. The best I could do was put a piece of duct tape on it. Worked like a charm though. Going to Ford today. Hopefully I will be able to get the old boot off.
Eric
Eric
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98 Expedition , rough idle
Well all ,
I finally got the errors code read Thanks to my wifes
cousin (who seems to be able to acquire almost anything).
It turns out that my error code was P0305, missfire on cyl #5.
I brokedown and pulled out the tools and found a mixture
of what looks like oil/water and dirt up to the top electrode of the
spark plug.
Seems that the thermostat seal has a slight leak in it and
it dribbles down into the spark plug location along with all the oil & dirt it can gather up.
The plug was in good condition (for almost 70K mi.). I will
replace them all in a while. But I will take it in for that bit of work.
Thanks all !!!!!!!!
I finally got the errors code read Thanks to my wifes
cousin (who seems to be able to acquire almost anything).
It turns out that my error code was P0305, missfire on cyl #5.
I brokedown and pulled out the tools and found a mixture
of what looks like oil/water and dirt up to the top electrode of the
spark plug.
Seems that the thermostat seal has a slight leak in it and
it dribbles down into the spark plug location along with all the oil & dirt it can gather up.
The plug was in good condition (for almost 70K mi.). I will
replace them all in a while. But I will take it in for that bit of work.
Thanks all !!!!!!!!
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98 Expedition , rough idle
Hi All,
I've been busy working on my ride. Had to change the spark plugs. You guys were right on , took me 6+ hours . The
parts store guy even gave me the wrong plugs first time . Went
back with original part to match up (finaly).
The car still ran shakey so , I checked the wires and
#5 front drivers side read open (with ohm meter) book said
approximately 2-4K ohms of resistance per foot (new one read 12K ohms).
Now with the new plugs and wires seems to back to it's
great running self. Now maybe a run to TJ for a relaxing vacation
or other stuff.
Ciao All
I've been busy working on my ride. Had to change the spark plugs. You guys were right on , took me 6+ hours . The
parts store guy even gave me the wrong plugs first time . Went
back with original part to match up (finaly).
The car still ran shakey so , I checked the wires and
#5 front drivers side read open (with ohm meter) book said
approximately 2-4K ohms of resistance per foot (new one read 12K ohms).
Now with the new plugs and wires seems to back to it's
great running self. Now maybe a run to TJ for a relaxing vacation
or other stuff.
Ciao All